Entry Type ID Date Applicable Rating System Primary Credit Inquiry (LIs) Ruling (LIs) Related Addenda/LIs Related Resources Campus Applicable Internationally Applicable Country Applicability Reference Guide (Addenda) Page (Addenda) Location (Addenda) Description of Change (Addenda) "LEED Interpretation" "10017" "2011-05-09" "Core and Shell" "EAc1 - Optimize energy performance" "In regards to the new LEED-CSv2.0 document posted 03/12/2010, will projects now be required to meet both a minimum energy for the Core and Shell only and also a minimum for the whole building based on an adjusted percentage? For the EAC1 template, should whole building energy be reported? What is considered Tenant energy? Should tenant HVAC energy be included in core and shell energy or tenant energy? Should two sets of calculations be run, one for whole building and one without tenant energy?" "The spreadsheet establishes new point thresholds for the project based on the percentage of energy influenced by the developer versus the total predicted building energy consumption. There is only one target minimum energy savings. Reporting will remain the same. All HVAC energy is considered to be ""influenced by the developer"" with the exception of server room energy since the developer influences the HVAC energy through the envelope design, and the outside air distribution design. One model should be run, with submetering for tenant energy. Applicable internationally." "None" "None" "X" "LEED Interpretation" "10020" "2011-05-09" "New Construction, Schools - New Construction, Core and Shell" "EAc1 - Optimize energy performance" "Is it acceptable for a project to utilize a campus solar farm to achieve points under EAc2, and at the same time utilize rooftop solar panels, tied directly into the building power system, to achieve points under EAc1?" "The solar farm can count towards EAc2, while the solar panels can count towards EAc1, and in fact, the PV generated on the building could be counted towards both EAc1 and EAc2 points. Applicable internationally." "None" "None" "X" "LEED Interpretation" "10021" "2011-05-09" "New Construction, Core and Shell" "EAc1 - Optimize energy performance" "For a building renovation where building employees participate in flexible working arrangements, resulting in a significant decrease in building energy and transportation costs per employee, is it acceptable to use the current building size, plus the expansion that would have been necessary to accommodate all existing plus new employees working from the building, as the baseline building case?" "ASHRAE 90.1-2004 Appendix G requires, under Table 3.1, that the equivalent dimensions for the proposed and baseline envelope, including roof, exterior wall, doors and perimeter area, shall be the same in both models. Applicable internationally." "None" "None" "X" "LEED Interpretation" "10022" "2011-05-09" "New Construction, Core and Shell" "EAc1 - Optimize energy performance" "For a Distribution Center, is it acceptable to distribute lighting in a manner that takes into account shelve placement, eliminating unnecessary energy consumption illuminating the shelves\' tops?" " Yes, design teams are encouraged to develop integrated lighting designs that improve efficiency while meeting the design intent of the owner. Strategic placement of lighting fixtures is an appropriate strategy for accomplishing improved lighting efficiency. Applicable internationally." "None" "None" "X" "LEED Interpretation" "10023" "2011-05-09" "New Construction, Schools - New Construction, Core and Shell" "EAc1 - Optimize energy performance" "If an area adopts ASHRAE 90.1-2007 as its energy code, is it acceptable to still use ASHRAE 90.1-2004 for the baseline model, even though such a building would no longer meet code in the area?" "The rating system language for EA Credit 1 specifically references ASHRAE 90.1-2004 Appendix G (without addenda) as the basis for documenting credit performance under Option 1. As such, there is no requirement for project teams to use ASHRAE 90.1-2007 to document compliance even if their local jurisdiction requires compliance with ASHRAE 90.1-2007. Applicable internationally." "None" "None" "X" "LEED Interpretation" "10025" "2011-05-09" "New Construction, Schools - New Construction, Core and Shell" "EAc1 - Optimize energy performance" "Per ASHRAE 90.1 Appendix G, in order to model an addition excluding the existing building, the HVAC system must be completely separate. Is it acceptable to model the addition separately if it shares steam to hot water heat exchangers with the existing building, but the air handling system is completely independent?" "It is acceptable to model the addition separately. Applicable internationally." "None" "None" "X" "LEED Interpretation" "10026" "2011-05-09" "New Construction, Schools - New Construction, Core and Shell" "EAc1 - Optimize energy performance" "Is it acceptable to use research on potential efficiencies of data center equipment, as published in an ASHRAE Journal article, to demonstrate the difference between baseline and design performance of a data center?" "The performance metrics in the article itself are based on models generated by authors to demonstrate ""order of magnitude savings possible"" and do not provide any confidence in the effectiveness of the measures listed. Efficiencies and energy savings should come from manufacturers\' documentation. Applicable internationally." "None" "None" "X" "LEED Interpretation" "10027" "2011-05-09" "New Construction, Schools - New Construction, Core and Shell" "EAc1 - Optimize energy performance" "For a building with two tenants, only one of whom is currently building out the space, is it necessary to include the space to be occupied by the future tenant within the project boundary?" "Because the tenant space comprises less than 50% of the total building area, the project should pursue certification under LEED for New Construction and include the tenant space in the credit calculations. For unfinished tenant spaces, tenant guidelines must be provided. Applicable internationally." "None" "None" "X" "LEED Interpretation" "10129" "2011-11-01" "New Construction, Core and Shell, Retail - Commercial Interiors" "EAc1 - Optimize energy performance" "LEED Core and Shell projects are is allowed to show energy savings associated with tenant improvement measures if documented in the lease agreement. Can anchor tenant leases, were executed well before the start of design, also be used? As a result of timing issues, it is not always practical to include specific energy efficiency measures in the lease agreement. Many of our tenants, especially supermarkets and other anchors, are extremely interested in energy efficiency and include these measures in their build-outs. All of these measures are documented in the tenants\' construction drawings, which are typically completed simultaneously with the core and shell drawings. \nWe desire to be able to include tenant energy efficiency measures that are documented in the tenants\' construction drawings in the LEED for Core and Shell energy model. We would argue that this approach has more certainty and credibility than measures documented in the lease agreement. We would be using measures in permitted, final construction drawings, not requirements that were agreed to during lease negotiations.\nPlease confirm that the LEED for Core and Shell project can include energy efficiency measures documented in the tenant\'s final construction drawings as part of the LEED for Core-and-Shell energy model. " "The energy efficiency measures for tenant spaces documented in the tenant\'s final construction drawings can be used as part of the LEED Core and Shell energy model if the tenant signs a letter confirming that the final construction documents will be implemented as designed; that any modifications to the final construction documents will be evaluated for their impact on energy efficiency; and that the overall efficiency savings contributed by the tenant improvements will be maintained between the final construction documents and the construction phase. Applicable internationally." "None" "None" "X" "LEED Interpretation" "10158" "2012-04-01" "New Construction, Core and Shell, Schools - New Construction, Retail - New Construction, Healthcare, Data centers - New Construction, Hospitality - New Construction, Commercial Interiors, Retail - Commercial Interiors, Neighborhood Development" "EAc1 - Optimize energy performance" "Can we take credit for a demand ventilation system for an automotive service area?\n\nEssentially we propose to model the service area in the Baseline Cases at 100% outside air at 1.5 CFM/sq.ft. during occupied periods to meet ASHRAE 62.1. We plan to model the service area in the Proposed Case with typical storage ventilation rate. See rationale below to validate our assumptions.\n\nWe further propose to model this energy efficiency measure in the standard credit energy models (not as an exceptional calculation) as part of the Baseline and Proposed Cases in order to accurately account for the differences in ventilation load. The differences are based on outside air conditions which change throughout the year and they also impact the supply air unit and fan sizes. The simulation program must size the equipment for the Baseline Case at the peak load and model it use 8760 hours in the year. \n\nASHRAE 62.1 lists a specific minimum ventilation rate for automotive service areas at 1.5 CFM/sq. ft. Ventilation reduction controls are not stated in Ashrae 62.1, nor are they mandated in ASHRAE 90.1-2007. The governing Mechanical Code (International Mechanical Code) optionally permits the use of approved automatic detection devices to control the required ventilation fans and/or make-up air systems. Large make-up air systems providing 100% outside air are still readily available and utilized in order to meet the mandated code. \n\nWe have utilized the following assumptions for modeling energy usage:\n\nBaseline Case - The exhaust ventilation system is modeled to operate at 1.5 CFM/sq.ft. during occupied hours per occupancy schedule. The modeling software automatically sizes the air conditioning system to operate as a 100% outside air system as the total CFM requirement exceeds the design load amount. The unoccupied fan cycle does not include the ventilation and only operates to maintain unoccupied thermostat set point.\n\nProposed Case - The exhaust ventilation system is modeled to be non-operational at any time. We make this assumption based on calculation and witnessed operation at like facilities with the identical control system in place. We have calculated carbon monoxide production based upon maximum estimated daily vehicle round trips through the service area. Eighteen service stalls with an average of 3 vehicles per day and 1 minute round trip drive time yields an estimated total vehicle drive time in the service area to be 54 minutes. The average modern vehicle with catalytic converter produces approximately 150 CFM of exhaust airflow at idle to slow speed containing approximately 1,000 PPM of carbon monoxide. 150 CFM X (0.1%) = 0.15 CFM of carbon monoxide production. The requirement to engage the exhaust ventilation system is 50 PPM of carbon monoxide. The volume of the space is 236,900 cu.ft. and would require 11.845 cu.ft. of carbon monoxide to engage the system. This would require 78.97 minutes of continuous operation without any dilution in a facility this size which exceeds the estimated maximum vehicle operation time of 54 minutes by 30%. The air conditioning equipment serving the area provides 800 CFM outside air and is equivalent to a complete air change twice a day and therefore doubling the daily total required operation time to 157.94 minutes. Operation of vehicles for diagnostic testing is excluded as there is a separate tailpipe extraction system in place to remove all exhaust during testing. \n\nCalculations are no substitute for actual conditions. We have interviewed service managers as to the operations of the emergency exhaust system controlled with a CO monitor system. The feed back is overwhelming that the emergency system is never engaged during normal operation. The technicians in these facilities have been trained in the control systems operations and do not desire to have their ""conditioned"" air purged from the building due to excessive operation of the vehicles within the space." "A project team cannot be awarded credit for demand controlled ventilation in an automotive service area, due to concerns over contaminants, and possible effects on indoor evironmental quality. As there is no current accepted methodology, the potential human health risks outweigh the energy savings." "None" "None" "LEED Interpretation" "10240" "2012-10-01" "Core and Shell" "EAc1 - Optimize energy performance" "The project is a retail shopping center. The developer proposes to seek Core & Shell (CS) LEED certification, and to encourage, but not require, tenants to seek Commercial Interiors (CI) certification. The interpretations requested apply to EA Credit 1, Option 1, Whole Building Energy Simulation, also referred to as Building Energy Modeling (BEM). We propose to use the Performance Rating Method for all energy consuming systems served by the Landlords meter, including the building envelope enclosing those spaces. There are no Landlord controlled energy consuming systems in the parts of the building enclosing tenant space. We propose for the building envelope enclosing tenant space to conform to ASHRAE 90.1 2007. This will be done by the prescriptive method if possible; otherwise we will use the Energy Cost Budget Method to prove equivalence. For this project, the core and each tenant space is separately metered by utility company meters. The developer will control only the core space and the building envelope. The building envelope will conform to ASRAE 90.1 2007, but will not be relied upon for major energy cost saving by the developer or by tenants. If the CS BEM includes all energy consuming systems served by the Landlord\'s meter; and excludes all energy consuming systems served by the tenant meters, the energy conserving measures applied by the Landlord will earn the maximum available EA 1 credits, and the project will be eligible for CS certification. If the CS BEM also includes tenant energy consuming systems, with no tenant energy cost reduction measures, the Landlord cannot apply enough reasonable energy cost reduction measures to qualify for the EA prerequisite, and cannot qualify for CS certification. The basic question is, can the Landlord qualify for CS LEED certification based only on work under his direct control, or must he mandate tenant energy cost reduction measures, as required to reduce total building energy cost by the prescribed level? A secondary question is how to apply the floor area limits of various requirements to the building. The building functions as a series of small spaces, not as a total building. Should the area of each space be used, or the total building area? " "The project is inquiring as to how to achieve credit for a prescriptive method under EAc1 for a Core and Shell Building in which the owner/developer will not require tenants to pursue increased performance measures. For Option 2, page 264 of the LEED Reference Guide for Green Building Design and Construction 2009 Edition (Updated June 2010) states ""To apply for credit under this option, a Core and Shell Project must comply with all requirements for the ASHRAE Advanced Energy Design Guidelines, including those that may be in the tenant\'s scope of work. A sales agreement or tenant leases may be necessary."" As a result, it does not appear the owner will have sufficient control over the future tenant installations to pursue Option 2. Also, for Option 3, it does not appear the project would comply with the credit requirements. Section 2 includes both lighting and mechanical system efficiency requirements which appear to be outside of the scope of owner control. If Option 3 is pursued, both Section 1 and Section 2 would need to be complied with to achieve credit. Please note, that there is a path available for credit under EAc1, Option 1 for Core and Shell buildings where the owner does not have control over the future tenant spaces. For these situations, owner/developer controlled spaces should be modeled in the proposed case as designed. For spaces/systems not controlled by the owner/developer, the proposed case should be modeled identically to the baseline case. A spreadsheet tool is available (here) which prorates the point threshold based on the owner/ developer controlled percentages. If the prescriptive options are pursued, documentation such as tenant requirements and a tenant lease agreement must be provided to verify the future tenants will meet the prescriptive requirements. The project also is inquiring as to how the floor area limits are applied to the various requirements to the building. The total building area within the scope of the LEED project submittal should be used to determine the building requirements. Applicable Internationally." "None" "CS 2009 EAp2-c1 ACP " "X" "LEED Interpretation" "10241" "2012-10-01" "New Construction, Existing Buildings, Core and Shell, Schools - New Construction, Retail - Commercial Interiors, Healthcare" "EAc1 - Optimize energy performance" "Many projects in Europe are connected to highly efficient district energy systems. However, the EAp2/EAc1 Option 2 guidance provided in the ""Treatment of District or Campus Thermal Energy in LEED V2 and LEED 2009 - Design & Construction"" (DESv2) document is not well-suited for the complex interconnected district energy systems with multiple fuel sources that are common in Europe. Many European countries already make use of the Primary Energy Factor (PEF) as a means of evaluating district energy performance and building energy performance. Is there an alternative compliance path available to document EAp2/EAc1 credit for the district energy system using the Primary Energy Factor in lieu of the DESv2 Option 2 compliance path?" "An alternative EAp2/EAc1 compliance path is available to document the energy performance for complex interconnected district energy systems in Europe using the Primary Energy Factor and the greenhouse gas emissions associated with these systems. The Sweden Green Building Council developed an approved method, ""Treatment of European District Energy Systems in LEED"" (available November 1, 2012), which may be used in lieu of EAp2 Option 2 of the ""Treatment of District or Campus Thermal Energy in LEED V2 and LEED 2009 - Design & Construction"" guidance. This compliance path is currently available for projects located in Europe only. The guidance is located at \n \nNote: The ""Treatment of District or Campus Thermal Energy in LEED V2 and LEED 2009 - Design & Construction"" (DESv2) is Optional Guidance for LEED 2009 projects. However, project teams that use the guidance must apply all relevant portions of the guidance. The alternative compliance path outlined in the ""Treatment of European District Energy Systems in LEED"" may only be used to replace Option 2 of the EAp2/EAc1 Energy Modeling Path defined in the DES v2 guidance. Project teams that opt to use the ""Treatment of European District Energy Systems in LEED"" method must comply with all other applicable requirements of the DES v2 guidance such as those defined for EA Credit 3, EA Credit 4, EA Credit 5, etc.\n \nApplicable Internationally; only for projects located in the Europe region. " "10239, 10243" "Treatment of Scandinavian District Energy Systems in LEED" "X" "LEED Interpretation" "10243" "2012-10-01" "New Construction, Core and Shell, Schools - New Construction, Healthcare, Retail - Commercial Interiors, Existing Buildings" "EAc1 - Optimize energy performance" "Many projects in Europe are connected to highly efficient district energy systems. However, the EAp2/EAc1 Option 2 guidance provided in the ""Treatment of District or Campus Thermal Energy in LEED V2 and LEED 2009 - Design & Construction"" (DESv2) document is not well-suited for the complex interconnected district energy systems with multiple fuel sources that are common in Europe. Many European countries already make use of the Primary Energy Factor (PEF) as a means of evaluating district energy performance and building energy performance. Is there an alternative compliance path available to document EAp2/EAc1 credit for the district energy system using the Primary Energy Factor in lieu of the DESv2 Option 2 compliance path?" "An alternative EAp2/EAc1 compliance path is available to document the energy performance for complex interconnected district energy systems in Europe using the Primary Energy Factor and the greenhouse gas emissions associated with these systems. The Sweden Green Building Council developed an approved method, ""Treatment of European District Energy Systems in LEED"" (available November 1, 2012), which may be used in lieu of EAp2 Option 2 of the ""Treatment of District or Campus Thermal Energy in LEED V2 and LEED 2009 - Design & Construction"" guidance. This compliance path is currently available for projects located in Europe only. \n \nNote: The ""Treatment of District or Campus Thermal Energy in LEED V2 and LEED 2009 - Design & Construction"" (DESv2) is Optional Guidance for LEED 2009 projects. However, project teams that use the guidance must apply all relevant portions of the guidance. The alternative compliance path outlined in the ""Treatment of European District Energy Systems in LEED"" may only be used to replace Option 2 of the EAp2/EAc1 Energy Modeling Path defined in the DES v2 guidance. Project teams that opt to use the ""Treatment of European District Energy Systems in LEED"" method must comply with all other applicable requirements of the DES v2 guidance such as those defined for EA Credit 3, EA Credit 4, EA Credit 5, etc.\n \nApplicable Internationally; only for projects located in the Europe region. " "10239, 10241" "Treatment of Scandinavian District Energy Systems in LEED" "X" "LEED Interpretation" "1600" "2006-10-23" "Core and Shell" "EAc1 - Optimize energy performance" "Our question deals with selecting the most appropriate HVAC system baseline for our project. Our project is a 3-story, 40,000 sf office building. It includes 10,000 sf parking, and 30,000 sf tenant improvement office and core space. Most of the offices and all core spaces will be served by a single VAV system consisting of a rooftop packaged air conditioning unit and electric resistance reheat at series fan-powered boxes in each zone. The rooftop unit delivers low-temperature supply air to the spaces, reset to a temperature dictated by the zone requiring the greatest amount of cooling. The rooftop unit also contains a gas furnace, which provides heating for the following infrequent scenarios: 1. During night low limit control, when three perimeter zones and one interior zone on any floor fall below the night low limit temperature setpoint. 2. During morning warmup, when outside air temperature is below an adjustable setpoint. Virtually all other heating needs are served by the electric resistance heaters at the series fan-powered boxes. Based on this predominant use of electric resistance heat, we have categorized our heating source as ""electric"" and have selected a ""packaged rooftop heat pump"" (System 4) for our baseline HVAC system per ASHRAE 90.1-2004 Appendix G Table G3.1.1A. Four considerations affected our interpretation of which baseline to use: 1. Heating source for the design. The two scenarios in which heating is provided by the gas furnace, identified above, do not comprise a significant proportion of the total heating required by the building. Rather, the majority of the building heating (approximately 90% of the total annual heating energy), is provided by electric resistance reheat at the fan-powered boxes. 2. Avoidance of fuel-switching. Although a ""packaged rooftop air conditioner"" with fossil fuel furnace (System 3) is specified for design buildings using a ""fossil/electric hybrid"" HVAC system, use of a System 3 baseline appears to create a situation of fuel-switching. Our design building heating source is predominantly electric, whereas the System 3 baseline heating source is a fossil fuel furnace. 3. Consideration of reheat strategy for both design and baseline models. The System 3 ""packaged rooftop air conditioner"" with fossil fuel furnace might be considered a reasonable baseline for comparison to our design building if the baseline system included electric reheat at each zone. However, based on Appendix G rules and guidance provided in the ASHRAE 90.1-2004 User\'s Manual, the System 3 HVAC system must be represented with a separate packaged single zone unit for each thermal zone in the baseline model, which implies that no zone level reheat is necessary. 4. Consequence of baseline requirement on future building HVAC designs. If the intent of Table G3.1.1A is to require a System 3 baseline for our particular design, the baseline has the effect of encouraging replacement of infrequently-used gas furnace heaters in rooftop units with less energy-efficient, electric heaters. Such a design change could occur relatively easily, especially during value engineering. These reasons - lower initial cost of an electric heater and the opportunity to show higher energy cost savings relative to an electric heat pump baseline - would seem to provide a compelling reason for changing the design by eliminating the gas furnace. It does not seem reasonable that this type of small design change to a rooftop packaged unit, replacing gas heat with electric, should become a pivotal issue in determining the correct baseline for LEED calculations. For these reasons, we consider System 4 to be the appropriate baseline for our project. Is this an acceptable baseline selection?" "The project team is seeking clarification regarding the Baseline Building system type selection. The proposed design system is heated predominantly by electric resistance reheat controls, but includes some fossil fuel heating for morning warm-up and night-cycle control. Based on the size and number of floors for the building, the Baseline system type selection will be either System 3 (PSZ-AC) or System 4 (PSZ-HP). The functions described for the gas furnace appear to be consistent with the functions accomplished with a preheat coil. Per ASHRAE 90.1-2004 Section G3.1.2.3, if the HVAC system in the proposed design has a preheat coil, and a preheat coil can be modeled in the baseline system, the baseline system shall be modeled with a preheat coil controlled in the same manner as the proposed design. The ASHRAE User\'s Manual states ""This means that adding a preheat coil is not something that can be credited toward a building performance rating."" System 4 is a valid selection for the Baseline Building system, assuming that the project does not attempt to take credit for natural gas heating versus electric heating in the Proposed Building energy model. If the energy modeling software is incapable of modeling a gas furnace preheat coil for PSZ-HP systems, then the heating source would have to be labeled ""Fossil/Electric Hybrid"", and the Baseline system type would be System 3. Applicable Internationally." "None" "None" "X" "LEED Interpretation" "1693" "2007-02-26" "New Construction, Core and Shell, Schools - New Construction" "EAc1 - Optimize energy performance" "We request the USGBC confirm our understanding that the 90.1-1999 ECBM and LEED modeling protocol allows us to receive credit for EAc1 energy cost savings for desuperheaters recovering heat from water source heat pump compressors, and using this heat to preheat service water heating, and that this can be done without an Exceptional Calculation, with the supporting discussion below. We understand that the heat recovery method would qualify as site-recovered energy as discussed under section 11.2.3 and its Exception, and is not included in the design energy cost, and the equivalent usage is met in the budget model by the backup energy source, which is electricity. Therefore, the measure is eligible for savings credit and to be modeled differently in the design model from the budget model. The desuperheaters and their heat recovery to service water heating can be readily modeled within eQuest and its computational engine, DOE-2.2, and therefore do not become an exceptional calculation for that reason. Therefore, the measure appears eligible for savings credit, and does not seem to require an exceptional calculation. Is this approach considered acceptable?" "The applicant is requesting clarification regarding whether desuperheaters must be modeled using the exceptional calculation methodology when the energy software program used for EAc1 compliance is capable of modeling heat recovery. The exceptional calculation methodology is only required when one of the following conditions are met: 1. The simulation program being used for the LEED EAc1 calculations cannot adequately model a design material or device 2. Input parameters that ASHRAE 90.1 requires to be modeled identically in the budget and proposed case must be modified to show the impact of the efficiency measure (e.g. schedule changes must be used to demonstrate improved efficiency, such as for demand control ventilation). 3. Previous LEED CIRs have mandated the use of the exceptional calculation methodology (e.g. - eQUEST is capable of modeling demand controlled ventilation, but since eQUEST accomplishes this by internally editing schedule values, the exceptional calculation methodology is still required for LEED v2.1 projects). In the case of desuperheaters, ASHRAE 90.1-1999 specifically requires condenser heat recovery to preheat service hot water under certain conditions (Section 6.3.6.2). Since heat recovery is prescriptively required under certain conditions, and since the software is capable of modeling desuperheaters without the use of supplemental spreadsheet calculations, the measure may be modeled without using the exceptional calculation method. The applicant should be sure to include all input assumptions regarding the desuperheaters in the input comparison table, and should provide sufficient information to confirm that condenser heat recovery does not have to be modeled in the budget case under the requirements of section 6.3.6.2. Applicable Internationally." "None" "None" "X" "LEED Interpretation" "1794" "2007-05-30" "Core and Shell" "EAc1 - Optimize energy performance" "The base building project is a new shell and core office tower of approximately 1.4 million gross square feet and 46 occupied floors. The building owner intends to only occupy approximately half of the total building general office space square footage, with the remaining tower floors and retail space available for future third party tenants. For this reason the LEED scope was defined to appropriately address these project parameters and registered under the guidelines: 1.LEED for Core and Shell Development v2.0 - Owner of Office Tower/Base Building 2.LEED for Commercial Interiors v2.0 - Owner occupied half of the tower general office space Can known tenant area building efficiencies associated with the owner occupied spaces be accounted for in the Core & Shell submission? The ""Core and Shell Energy Modeling Guidelines"" section of the Core & Shell reference guide states in subsection 2.2.1.2, ""If tenant lighting is designed and installed as part of the core and shell work, the project team may model the designed or installed lighting systems."" This has been interpreted to credit the Core & Shell submittal, and subsequently the owner, for designing the owner occupied spaces in concert with the base building. For our project, the same design team has designed both the owner occupied tenant spaces and the base building, and thus is more similar to a NC project for this portion of the project. Please confirm that the proposed model could include the As-Designed lighting systems throughout all C/S spaces and owner occupied tenant spaces, while the basecase building would include ASHRAE 90.1-2004 thresholds for all spaces. As an extension of this intent, please confirm building efficiency measures targeted at the owner occupied tenant plug and process loads (in particular, the high performance data center), can be accounted for in the C&S submittal. Assuming well documented baseline and as-designed conditions, please confirm that the proposed model could include equipment power calculated from the high performance data center and plug load data, while the basecase model would include equipment power calculated from the baseline data center and plug load data. An NC submittal would allow credit to be taken for the high performance data center, while the Commercial Interior submittal does not allow credit to be taken. The high performance data center will provide significant energy savings that the design team would not like to have lost in the LEED process. Similarly, can building energy savings due to daylighting be accounted for in the Core & Shell submittal? Daylighting energy savings are a product of daylighting systems and lighting controls. For this project, all daylighting systems are designed for all spaces, they are integral to the shell, and furthermore, are included in the base building or Core & Shell budget. All owner occupied spaces have daylight photosensors, while it is planned for tenant spaces to be contractually required to utilize daylight photosensors upon interior build out. Please confirm that the proposed model could include the daylighting impact on the As-Designed or ASHRAE 90.1-2004 lighting systems throughout all owner occupied and non-occupied tenant spaces, while the basecase building would include no impact from daylighting." "Where daylighting controls are designed and installed as part of the Core & Shell package, they can be included in the model of the proposed design. Contractual requirements for tenant spaces to use daylighting photosensors cannot be included in the model of the proposed design because it is unknown as to how these spaces will be occupied and how the controls will be integrated into the tenant finish. As for process load efficiency improvements, if the data center is being designed and installed as part of the Core & Shell package, then an exceptional calculation can be provided per ASHRAE 90.1-2004 to document the claimed savings. Those energy efficiency measures accounted for in the LEED Core & Shell project under EAc1, cannot be claimed in the EAc1 submittal for Commercial Interiors. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "1849" "2007-08-13" "New Construction, Core and Shell, Schools - New Construction" "EAc1 - Optimize energy performance" "Our LEED project consists of two office buildings of approximately 160,000 sf each plus a central refrigeration plant and parking deck. All buildings will be submitted as one LEED project. The project is currently under construction. The energy model for the project was constructed using Trace700 and is a comprehensive model of all three structures. In addition to the 20% energy savings already being reflected in the model, substantial energy savings will be realized by the investments the Owner has made in advanced energy efficiency measures such as daylighting through a central atrium and interior glazing, raised floor thermodynamics and a hybrid HVAC system. Due to limitations of the Trace700 modeling software, the contributions of these sophisticated energy efficiency measures are not currently reflected in the modeled energy savings. To support the ongoing operations of the building, the Owner has invested in a measurement and verification system, which per EA Credit 5, will include measurement of all electrical power panels, lighting panels broken into interior and exterior lighting, and all hvac equipment. The M&V system will measure and trend demand and consumption of electricity, water and natural gas on an hourly basis for all hours of the year. The project cannot bear the added expense that would be required to perform extensive hand calculations, daylight models or to use more sophisticated energy modeling software, but we would like the Owner to be recognized with LEED points for the contribution that their investment in energy efficient design strategies represents. We would like to incorporate the actual measured performance of the lighting, power, and HVAC systems into the Trace700 model. We propose to delay our LEED application at the end of construction and with all buildings in operation, to measure the building systems performance for 3 to 6 months through the M&V devices. We would then substitute values from the measured performance into the design case energy model. The data would be input on a watt/sqft, kw/cfm, btu/hr, cfh, or gal/min basis. We believe that using measured performance data in the creation of the final design case model would be a cost-effective, accurate means of accounting for the contributions of sophisticated energy efficiency measures, and request permission to use this approach on our project." "The CIR is asking if actual logged energy use data being collected for EAc5 can be used to more accurately represent the proposed building energy use for EAc1, with the caveat that the project certification will be held up until this data has been collected and the energy model has been calibrated. It should be noted that incorporating measured data into an energy model is a strategy fraught with many technical challenges. USGBC encourages project teams to use energy models as a design tool. That said, the proposed technique is acceptable, provided the following conditions are met: [1] One full year\'s worth of energy use data must be included to account for seasonal effects. Additionally, this gives time for the commissioning of the facility to be completed and the ""bugs"" worked out of the system. [2] The collected energy data cannot be directly compared to the baseline modeled energy data. Instead the collected data should be used to populate the inputs to the energy modeling program (ie- plug loads, lighting densities, etc). This is because modeling programs inherently contain assumptions and methodologies that do not directly correspond to actual building energy use. By still running a simulation for the baseline and proposed cases, these discrepancies effectively cancel each other out. [3] The applicant must be able to show that the occupancy schedules, building set points, and intended use of the facility are the same in the baseline and proposed case. [4 The baseline energy simulation must utilize a weather file that represents the same metrological conditions that occurred during collection of the energy use data. [5] Submit all documentation required for an Exceptional Calculation Methodology, as described in ASHRAE 90.1-2004 Appendix G. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "1853" "2007-08-13" "New Construction, Core and Shell" "EAc1 - Optimize energy performance" "Our project is a 573,000 SF warehouse facility in a mild climate. The facility is designed to function as a distribution facility at a trucking hub used to store and transfer goods. The typical set-up for a project of this type in the region is to have no mechanical cooling, ventilation and heating (for freeze protection only, temperature set-point 45F) is provided by series of roof-top units with gas-fired furnace. These units are typically constant volume. Since this project is pursuing certification under the LEED-CS v 2.0 rating system, to attempt any points under EA credit 1, we have to follow ASHRAE 90.1-2004, Appendix G - Performance Rating Method. Following the ASHRAE 90.1-2004, Appendix G - Performance Rating Method for a project of this type and size, we will have to model the baseline system as a packaged rooftop VAV with reheat provided by a fossil fuel boiler. A project of this size and type would not have anything even close to this baseline system. Also the modeling protocol requires the project to be modeled with mechanical cooling. Due to the unique nature of the project and its sheer size, it appears that the credit requires the project to use more energy to show that it saves energy. To address this issue, we are proposing the following adjustment to the modeling protocol - Proposed building - Model as designed in terms of envelope, HVAC systems, lighting systems, power distribution and schedules of operations Baseline building - Use the ASHRAE 90.1 section 11 and model as system 11 without mechanical cooling. All other systems will be modeled at minimum required efficiencies as per ASHRAE 90.1-2004. All schedules will be modeled as in the proposed model. Also the outside air rates will be maintained as per the proposed model. We believe that this approach will allow the project to pursue energy efficiency and take credit for any measures that they may apply. We also believe that this variance will allow the integrity of the rating system as it will not require the team to spend extra energy and money to demonstrate achievement of a credit. While the team acknowledges that not all credits apply to all projects, it is very difficult to make a case for green building without demonstrating energy efficiency from the view-point of the owner." "The CIR is asking what to use for proposed and baseline systems to meet the requirements of ASHRAE 90.1-2004 while still fairly representing the warehouse nature of the project. The answer depends on whether the space is classified as conditioned, semi-heated, or unconditioned. As per the ASHRAE 90.1-2004 Users Manual, a space is ""unconditioned"" if it has no cooling and a heating system of less than 3.4 BTUH/SF. A space is considered ""semi-heated"" if it has a heating system with a capacity greater than 3.4 BTUH/SF, but less than the climate specific value that can be looked up on table 3.1 of the ASHRAE 90.1-2004 Standard. If a space contains a cooling system greater than 5.0 BTUH/SF or a heating system greater than that listed in Table 3.1, then it falls in the ""conditioned"" category. The above criteria are based on the total output capacity of the equipment. IF THE SPACE IS UNCONDITIONED OR SEMI-HEATED: ASHRAE 90.1 modeling protocol is based around typical occupied and conditioned buildings. It is not meant to address industrial/manufacturing ""process"" areas, which warehouses may fall under if they meet the requirements of unconditioned or semi-heated spaces. These spaces fall outside the realm of ASHRAE 90.1-2004 and the modeler is asked to include them in the model ""as-is,"" meaning, in this case, including only a heating system and no cooling. The systems should be identical in both the baseline and proposed cases. If the project wishes to show energy savings due to the HVAC system in these areas, an Exceptional Calculation Method (ECM) must be used. See ASHRAE 90.1-2004 G2.5 for this procedure. IF THE SPACE IS CONDITIONED: If the heating provided to the space exceeds the thresholds set forth in Table 3.1 of ASHRAE 90.1-2004, then the standard modeling methodology should be used even if it results in systems that are different than the industry standard for the space type. Please note that typically in a warehouse facility there are some spaces that are fully conditioned (offices, break rooms, etc.). Please follow the standard ASHRAE 90.1-2004 Appendix G protocol for these areas. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "1858" "2007-08-27" "Core and Shell" "EAc1 - Optimize energy performance" "Our project is a 50,000 sq.ft. speculative office building applying for LEED-CS v 2.0 certification. When the design process began, no tenant space was leased. Presently, a potential tenant is proposing altering the base building. For example, the client wishes to add skylights to the building as part of their tenant fit-up (not as a part of our contract). Since this is not part of our scope of work, we would like confirmation that this kind of change is not to be included in our energy model and overall application." "The inquiry is seeking clarification on how to distinguish between the core and shell scope and the tenant portion of scope for a project. If the work performed is not within the core and shell scope, it can be excluded from the all relevant prerequisite and credit calculations and should be modeled as energy neutral. A clear delineation of the scope of the core and shell project relative to the tenant portion should be provided with the LEED submission, including a list of all the alterations requested by the tenant. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "1870" "2007-09-10" "Core and Shell" "EAc1 - Optimize energy performance" "The Washington Street Office Project\'s original owners, McShane Corporation has been considering pursuing LEED CS certification for some time. As the building was not originally designed with LEED CS intent, modifications are required to meet several of the requirements to receive certification. McShane recently sold the building prior to finalizing the decision to pursue LEED CS. The sale of the property and the timing of the ownership change happened to coincide with the timing of the LEED credit change, now requiring 14% energy optimization as a prerequisite. A decision of whether to pursue LEED certification then rested in the new owner\'s hands. The close of the sale and subsequently the decision to pursue LEED certification was agreed to by the new owner. At initial review, the project budget would need to be increased by at least $850,000 to achieve the 2 credits, significantly impact the schedule due to the redesign of the mechanical systems and governing agency reviews and the new owners are not prepared to increase the budget or schedule by this significant amount. They are willing to increase the budget to achieve many other credits that have much less impact, and are excited about the prospect of a LEED CS certified office building in this high profile location along the new light rail line running through Phoenix. Unfortunately we have been informed that if it is the decision of the USGBC that these credits must be achieved, the owner\'s plan to pursue certification would be stifled. This, in turn, would eliminate most of the environmental elements that we have discussed incorporating into the project to achieve the LEED certification. We have been further informed by our energy modeler has 3 large office buildings (150,000 + sf) in the last two weeks who are in danger of not meeting the USGBC requirement of 2 energy credits. This is largely due to Appendix G HVAC system requirements (Chilled water VAV) as compared to the water-cooled self contained VAV (DX) in the design. We are concerned that for LEED CS especially large buildings, this criteria may be too restrictive as the code itself provides for an extremely efficient design. Please let us know your decision as soon as possible. Thank you" "As per the member-balloted update posted to the registration page of the USGBC website, all projects registering after 6/26/2007 (excepting LEED for Homes and LEED for Neighborhood Development projects) must achieve a two-point minimum savings for EAc1. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "1930" "2007-12-05" "Core and Shell" "EAc1 - Optimize energy performance" "The project in question will be a core & shell warehouse building. The first sixty feet inside the loading dock doors is considered a staging area. Due to the nature of this space, this area will remain an open area, without walls or storage racks, regardless of the tenant layout. Our core & shell warehouse project developer/owner proposes to install skylights in the perimeter zone (staging area) of the facility to afford the tenant daylighting in the loading areas of the facility. In addition, the developer/owner will install a daylighting control system with photosensors (minimum one per perimeter zone and tenant) in the core & shell facility. Tenant design guidelines will require that the tenant connect their installed lighting in these perimeter zones to the daylighting control system. Appendix G of ASHRAE 90.1-2004 states that the proposed case may take advantage of daylighting controls when installed. The ambiguity and thus our question lies in the case when the tenant will install the lighting but the owner has provided both a building envelope congruent with interior daylighting design strategies and a control system that will reduce electric lighting automatically due to the available daylight. With regards to Energy & Atmosphere Credit 1, Appendix G of ASHRAE 90.1-2004 and a core & shell building, can the proposed case energy model account for the electric lighting savings (lighting designed and installed by the tenant) that result from use of daylighting controls (provided by the owner) in conjunction with the installed skylights (provided by the owner)? In our model, the savings and skylights will be restricted to perimeter zones only." "The proposed case can account for the electric lighting savings from daylighting controls relative to the allowed lighting power density as long as connecting the installed lights to the daylighting controls is required in the tenant lease agreement. Please see the LEED-CS errata posted on November 2 for details on the tenant sales and lease agreement credit compliance path. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "1931" "2007-10-23" "New Construction, Schools - New Construction, Core and Shell" "EAc1 - Optimize energy performance" "The project is an existing landmarked building in NYC pursuing LEED Core & Shell certification. Specifically, the building will undergo a gut rehab of all its floors. The building is currently served by four CFC chillers. To increase the energy efficiency of the building, and to obtain the two EAc1 points, the building plans to replace the CFC chillers with efficient chillers that also comply with the requirements of EAc4 Enhanced Refrigerant Management. Energy modeling projects that chiller replacement will result in $48,200/year energy cost savings. The cost of replacing chillers is high, because piping and ducting added over the years to the mechanical room are making the removal of the chillers impossible without changes to the MER. The cost of replacement including changes that would be needed for piping, controls and modifications to existing mechanical room is estimated to be 4-5 million dollars, resulting in a simple-payback above 80 years. Under LEED-EB, the Ozone protection prerequisite recognizes that if replacing chillers is not economically feasible, or if the simple-payback of the replacement is greater than 10 years, an alternate compliance path would be acceptable. The path recommended is that the CFC-based refrigerants be maintained, and the annual leakage be reduced to 5 percent for the life of the units (the requirements for LEED-EB). We believe that this indicates that flexibility can be granted when economic conditions are adverse, and would like to propose that such flexibility to granted to the LEED CS EAc1 in this particular case. Chiller replacement in this building is not economically feasible, but the owner has committed nonetheless to phase in new chillers over the period of 5 years. The 5-year period is primarily due to the large economic burden required by a replacement that does not have a reasonable payback. Computer modeling projects that with this replacement the Core & Shell will meet the 2 credit requirement for EAc1. We propose that replacing the chillers over 5 years is much better than retaining the current chillers, both for energy use and for ozone-depletion reasons - even with care for CFC leakage. With the owners committed to phasing in the new non-CFC chillers within 5 years, will this be acceptable to use the new, planned chillers for meeting the 2 point requirement for EAc1?" "Phasing in of new, non-CFC chillers within 5 years appears to meet the intent of EA prerequisite 3 on Fundamental Refrigerant Management. Prior to phase-out, the annual leakage of CFC-based refrigerants must be reduced to 5% or less using EPA Clean Air Act, Title VI, Rule 608 procedures governing refrigerant management and reporting. EAc1, Energy Performance Optimization, should not include the future chillers. This is covered by Appendix G, section G1.3 (p.169), which states that parameters relating to future components shall be identical in determining the baseline and proposed building performance. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "1943" "2007-11-28" "Core and Shell" "EAc1 - Optimize energy performance" "Our project is a core and shell 6 story office building. The project was registered after June 29, 2007, and, therefore is required to meet 14% energy savings over the baseline building performance. Currently, our energy model reflects a proposed design of 12% improvement. Unfortunately, we cannot make any modifications to the mechanical design or building envelope at this point in the project. The last option to meet the new requirement is to include lighting efficiencies in the tenant space by specifying and requiring that tenants design not to exceed 1.10 watts/sqft (which brings the overall project above 14% for the proposed building performance) This requirement will be stipulated in the lease with the proper verification process approval by the owner before each tenant improvement is submitted to the Building Department. If all the tenant improvements specifications require the lighting to be designed not to exceed 1.10 watts/sqft., can we include the tenant space in the model to allow us to meet the new 14% requirement?" "The applicant is requesting a variance to the LEED-CS energy modeling protocol to allow them to include the future design for tenant lighting. This approach is acceptable based on published erratum for LEED-CS v2.0 on the USGBC website (http://www.usgbc.org/ShowFile.aspx?DocumentID=3334). Please note in your submittal that this approach is being followed. Also please provide copies of the typical lease/sales agreements clearly highlighting the lighting requirements, per the modeling for this credit, that need to be met, as well as how these requirements will be enforced. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2030" "2008-03-04" "New Construction, Schools - New Construction, Core and Shell" "EAc1 - Optimize energy performance" "The project is a large mixed use complex which will include a high rise residential tower, a mid rise hotel, a theater, retail base under each of the above 3 buildings and parking facilities associated with all of the above. There are several energy saving measures being considered for systems which are not addressed in ASHRAE 90.1-2004 prescriptive requirements or appendix G. Please advise if the proposed approach to modeling is acceptable. 1. The high rise residential tower includes provisions for individual clothes dryers in each apartment. Thus the building will include engineered dryer exhaust systems to serve the stacked clothes dryers. In accordance with manufacturers recommendations and good engineering practice, the exhaust systems will be sized based on a 60% diversity factor to be able to function during periods of high usage. Typically such systems are constant volume systems that exhaust air continuously, even when most of the dryers are off. We are proposing to use a variable volume system which will modulate the fan speed to maintain the recommended pressure in the riser at all times. This will substantially reduce fan energy and also reduce the required make-up air heating and cooling costs, since the make-up air unit will be VAV and reduce volume in proportion to the reduction in dryer exhaust volume. ASHRAE 90.1 - 2004 does not address requirements for such systems therefore we believe it is justified to model the baseline system as constant volume exhaust with corresponding constant volume make-up air. The make-up air unit also includes capacity to match the toilet exhaust. However the toilet exhaust is less than the dryer exhaust and makes up only about 40% of total exhaust. We propose to provide heat recovery from the toilet exhaust to the make-up air. We believe that the baseline model can be set up without heat recovery from the toilet exhaust based on the fact that the system meets exception 6.5.6.1 (h) where the largest exhaust source is less than 75% of the design outdoor airflow and thus is not required to have heat recovery. 2. The lower level parking garage is classified as enclosed and thus mechanically ventilated. The parking garage serves the hotel and residential building and thus will be in use 24 hours a day. We are proposing to provide a system of carbon monoxide sensors and associated controls to operate the ventilation for areas of the garage only as needed to maintain" "Three proposed modeling approaches have been described in this request. 1. The project team proposes to model the baseline case toilet exhaust without heat recovery. This approach is not acceptable. Sub-section (f) under ASHRAE 90.1-2004 Section G3.1.2.10 (f) states that ""this exception shall only be used if exhaust air recovery is not used in the proposed design."" While Section 6.5 is a mandatory section for the purposes of meeting EAp2; modeling guidelines should be followed as per ASHRAE 90.1-2004, Appendix G. 2. The project team proposes modeling the parking garage ventilation system as variable, dependent on carbon monoxide sensor readings and the baseline case as constant. This is acceptable, but should be modeled as an exceptional calculation method if automatic controls cannot be explicitly modeled using the approved energy modeling software. Documentation must be provided that supports the savings and assumptions made if using an Exceptional Calculation Method. Please refer to ASHRAE 90.1-2004 Section G2.5 for further guidance. 3. The project team proposes that heat recovery does not have to be modeled in the baseline case for a central boiler plant/transformer vault ventilation system. This approach is acceptable, given that the air is tempered to 50" "None" "None" "X" "LEED Interpretation" "2047" "2008-03-04" "New Construction, Schools - New Construction, Core and Shell" "EAc1 - Optimize energy performance" "ENERGY & ATMOSPHERE: Minimum Energy Performance (EAp20) 4/30/2005 - Credit Interpretation Request The Saranac is a renovation and historic preservation of a 4 story hotel. The building will be converted into a multi-use facility that will include housing, offices, symposium space, theater and restaurant uses. The building is designated as a contributing structure to the Downtown Spokane National Historic district. the building is also on the local Historic Register and is subject to review of the local Landmark Commission. The design restrictions will result in restoring the storefront and primary elevations to 1900 era appearance. In our case the entire building will be renovated but the esterior appearance of the building will remain largely unchange with the exception of the addition of exterior sun shades on the non-primary elevations. The building systems will be replaced. Can the buildings existing envelope chariteristics be used to extablish the energy usage baseline per ASHRAE 90.1 (Section 4.1.2.2)? 5/23/2005 - Ruling Yes. As established in the EAp2 CIR Ruling dated 3-11-03 and ASHRAE 90.1 Sections 4.1.2.2, the historical facade is exempt from minimum energy performance. Section 11.4.2 also states ""for existing buildings, the budget building design shall reflect existing conditions prior to any revisions that are part of this permit."" _________________________________ Based upon this CIR I have a question about our current project, the renovation of an existing mill building into spec office space. Please note that the mill building is ""specifically designated as historically significant by the adopting authority or is listed in \'The National Register of Historic Places\' or has been determined to be eligible for listing by the US Secretary of the Interior"" per ASHRAE 4.2.1.3. I would like to confirm the following: 1. This CIR which was filed for a New Construction project applies to a Core and Shell project. Please confirm. 2. We believe this CIR allows us to use the original facade/envelope conditions to set our minimum energy performance as required for EA Prerequisite 2. Please confirm. 3. We believe this CIR allows us to run our energy model using the original facade/envelope design conditions to set the baseline for energy model comparison with the renovated facade/envelope design. Please confirm. 4. When we compare the original envelope against the renovated envelope (which can only consist of new windows and added roof insulation per the Historic Registry guidelines) our energy performance, based upon cost, increases by 23%. -We believe that this means we meet EA Prerequisite 2. Please confirm. -We also believe that under credit EA-1 we would qualify for 6 points as this is an Existing Building Renovation. Please confirm." "Based on the information provided, it appears that the requirements for EAp2 have been met and if this project achieves 23% savings in energy, incumbent on verification of documentation submitted during the review process, it would qualify for 6 points for an existing building renovation. In response to the questions raised: 1. This particular CIR, which was filed for a New Construction project, can be applied to a Core and Shell project. 2. Yes, the referenced CIR and ASHRAE 90.1-2004 Section 4.2.1.3 Exception (a) allows the project to meet the minimum energy performance requirements of EAp2. 3. This issue is unrelated to the original CIR, but the approach is acceptable under the requirements of ASHRAE 90.1-2004 Table G3.1 No. 5, (f) under Baseline Building Performance, which states that ""for existing building envelopes, the baseline building design shall reflect existing conditions prior to any revisions that are part of the scope of work being evaluated."" Applicable Internationally\n" "None" "None" "X" "LEED Interpretation" "2048" "2008-03-04" "New Construction, Schools - New Construction, Core and Shell" "EAc1 - Optimize energy performance" "This project is seeking a single LEED-CS certification for 12 free standing structures in close proximity at a single retail outlet shopping mall. Per ASHRAE 90.1-App. G protocol, each structure will be modeled individually to accurately represent the thermal envelope and building orientation comparisons. When inputting information into the EA credit-1 online template, should the energy performance for all twelve buildings be totaled and input as a single amount for both baseline and proposed (i.e. will a single EA template input be allowed by adding the energy model performance of each structure to reach a total for input on the template)? The alternative would be treating each structure individually (12 EA template inputs) and averaging all energy performance differentials to determine the total project EA credit." "The project team is requesting confirmation on submitting the energy performance information for 12 free-standing structures. USGBC has an application guide for LEED-NC projects submitting multiple buildings in one application (http://www.usgbc.org/ShowFile.aspx?DocumentID=1097). This guidance can be used by Core and Shell projects when applicable. For EAc1, you may input the data for all buildings into one template. Applicable Internationally." "None" "None" "X" "LEED Interpretation" "2078" "2008-04-23" "New Construction, Core and Shell" "EAc1 - Optimize energy performance" "The project is a large mixed use complex which will include a high rise residential tower, a mid rise hotel, a theatre, retail base under each of the above 3 buildings and parking facilities associated with all of the above. The following important energy saving measures is being considered for a system which is not addressed in ASHRAE 90.1-2004 prescriptive requirements or appendix G. Please advise if the proposed approach to modeling is acceptable. 1. The high rise residential tower includes provisions for individual clothes dryers in each apartment and will include engineered dryer exhaust systems to serve the stacked clothes dryers. In accordance with manufacturer\'s recommendations and good engineering practice, the exhaust systems will be sized based on a 60% diversity factor to be able to function during periods of high usage. Typically such systems are constant volume systems that exhaust air continuously, even when most of the dryers are off. We are proposing to use a variable volume exhaust system which will modulate the fan speed to maintain the recommended pressure in the riser at all times. We are also proposing to use a variable volume make-up air system which will vary the make-up air volume to match the exhaust flow rate. Both systems will substantially reduce fan energy and also reduce the required make-up air heating and cooling costs. ASHRAE 90.1 - 2004 does not address requirements for such dryer exhaust systems therefore we believe it is justified to model the baseline system as constant volume dryer exhaust with constant volume make-up air system. The proposed design will reflect the discussion above and be modeled as variable volume exhaust with variable volume recovery. Neither the baseline nor proposed design will include heat recovery because applicable codes prohibit any obstruction in the dryer exhaust systems. Please confirm whether modeling the baseline as constant volume exhaust and constant make-up without heat recovery and the proposed design as variable volume exhaust and variable volume make-up air without heat recovery is an acceptable modeling approach." "The project team is requesting verification of whether a variable volume exhaust system and variable volume make-up air system for stacked dryers in a residential building can be compared to a constant volume exhaust system in the Baseline energy model. As indicated by the project team, this issue is not addressed in ASHRAE 90.1-2004 prescriptive requirements or in Appendix G. Credit for systems not specifically addressed in the Appendix G modeling methodology must be modeled using the Exceptional Calculation Method, and theoretical and/or empirical information supporting the accuracy of the calculation method must be included. If the project submits an Exceptional Calculation Method to document credit for variable volume exhaust system and variable volume make-up air system for stacked dryers, they would need to clearly document: 1. That the Baseline system defined (including both the constant volume controls and fan capacities) is consistent with standard practice for similarly sized, newly constructed high-rise residential buildings. 2. How the control sequences will be applied to the project to achieve a true reduction in make-up air and exhaust-air volume during periods of low dryer usage (it is unclear how the pressure in the riser will correlate to the quantity of dryers in use, or how the makeup air and exhaust air volumes will be tracked with one another). Applicable Internationally." "None" "None" "X" "LEED Interpretation" "2084" "2008-04-23" "Core and Shell" "EAc1 - Optimize energy performance" "This question is in regard to a mixed use series of buildings planning to apply for certification as a LEED CS Campus project. The project is designed to be built containing no interior public common areas. The only common area air conditioned space will be the elevator mechanical room. The interior tenant spaces within the project will be built only to raw shell specifications with no electrical or mechanical fixtures or finishes, lighting or air conditioning. All interior lighting and HVAC equipment for specific tenant areas will be installed by the future tenants. Only exterior project lighting will be provided by the Developer. Therefore, the question is as follows: What is considered baseline for energy use by USGBC in a CS Campus building project, where the core and shell is delivered in a raw shell condition, with no interior lighting or HVAC to be installed by the Developer?" "The applicant is requesting clarification regarding what is considered the baseline for energy use in a Core and Shell building where all interior lighting and HVAC systems will be installed by the tenant. Concerns relating to modeling for CS applicants are outlined in the LEED-CS Reference Guide under Core and Shell Modeling Guidelines and Core and Shell Concerns and Calculations. Interior lighting in the baseline building should be modeled using the Building Area method or the Space-by-Space method as defined in ASHRAE 90.1-2004, Table 9.5.1 or 9.6.1. The baseline building HVAC system should be based on Table G3.1.1.A and Table G3.1.1B in ASHRAE 90.1-2004. Where no heating or cooling system exists in the proposed building, or, the system will be installed by the tenant and is unknown, the system characteristics in the proposed building shall be identical to the system in the baseline building design according to ASHRAE 90.1-2004, Table G3.1 (10) and LEED-CS Reference guide. Table G3.1 (10) in ASHRAE also states that, if no proposed heating system exists, the baseline system determined in Table G3.1.1.A should be electric. In addition to HVAC systems and lighting, the project should also include equipment and process energy according to certain requirements outlined in the LEED-CS Reference Guide. It is important to point out that in the case of Core and Shell buildings, not only the baseline, but also the proposed building needs to follow a certain modeling protocol to meet Option 1- Whole Building Energy Simulation in accordance to LEED-CS. Since tenants install all or part of HVAC systems, lighting, equipment etc, and full design might not exist, certain stipulations need to be incorporated in the proposed building simulation as well. In addition, tenant spaces are treated separately to core and shell spaces in the outlined requirements in LEED-CS. Concerns relating to modeling for CS applicants are outlined in the LEED-CS Reference Guide under Core and Shell Modeling Guidelines and Core and Shell Concerns and Calculations. The applicant is recommended to study theses guidelines carefully since these guidelines should be followed in parallel to ASHRAE-90.1-2004, Appendix G. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2095" "2008-04-25" "New Construction, Core and Shell" "EAc1 - Optimize energy performance" "The project is a high-rise residential building that is being applied under LEED-CS certification. Living units are being designed without air-conditioning system, since generally the people use natural ventilation during summer. Building spaces with regular occupation, such as bedrooms and living rooms, will be furnished with operable windows only, without mechanical systems. Therefore, under ASHRAE Standard 90.1 the entire building would be defined as unconditioned space, and the envelope does not need to comply with mandatory provisions of that Standard. Following this interpretation, the scope of work for this project would be limited to sections 7, 8, 9 and 10 of ASHRAE Standard 90.1, as the building will be provided with: service water heating; power distribution systems; lighting systems for common areas; and electric motors (stairs ventilators, water pumps and sewage pumps). In order to achieve the minimum energy performance prerequisite needed for LEED certification, only the lighting system for common areas and the service water heating were identified by the design team as the scope of work to be treated under ASHRAE Standard 90.1 and modeling rules of appendix G. This CIR is to clarify three questions: 1. Is this building eligible to certification under LEED, even without HVAC system? 2. If affirmative, the minimum energy performance has to be achieved only for those systems that will be provided by the owner, i. e., lighting system for common areas and service water heating? 3. Can natural ventilation be used as an energy efficiency strategy to achieve the minimum energy performance, in similar way as discussed in a CIR posted in 03/22/2007 (through an Exceptional Calculation Methodology)?" "1) Yes, the project is eligible for LEED certification. 2) Yes, the minimum energy performance and energy savings only applies to systems supplied by the owner. PLEASE NOTE that this project must comply with the mandatory provisions (Sections 5.4, 6.4 (when applicable), 7.4, 8.4, 9.4, and 10.4) of ASHRAE 90.1-2004, which includes the Building Envelope. Section 5.1.2.2 of ASHRAE 90.1-2004 clearly states that ""spaces shall be assumed to be conditioned space and shall comply with the requirements for conditioned space at the time of construction, regardless of whether mechanical or electrical equipment is included in the building permit application or installed at that time."" 3) Yes, natural ventilation can be used as an energy efficiency strategy to achieve minimum energy performance through the Exceptional Calculations Methodology approach outlined in CIR Ruling 3/22/2007. Credit achievement is contingent on the submittal documentation and compliance with the stated method to the satisfaction of the certification reviewer. Please be sure to submit the documentation outlined in the CIR in order to determine compliance during LEED certification. Applicable Internationally. " "1734, 5152" "None" "X" "LEED Interpretation" "2113" "2008-05-27" "Core and Shell" "EAc1 - Optimize energy performance" "A project consists of the renovation of 8 floors of an existing building intended for multi-tenant mixed office and retail use. The building qualifies as a historic building. The project is registered under the LEED Core and Shell (CS) rating system. The floor plan layouts have been designed in such a way that essentially all Core areas have been eliminated (Core and Tenant areas being defined thru the LEED CS v2.0 guidelines). The only owner-operated equipment is portions of a common ventilation system serving select floor areas. All remaining floor areas, entranceways, perimeter areas, and elevator lobbies will be served by equipment operated by the Tenants. Our intent is to only model the energy consumption used by the Proposed owner-operated ventilation system and compare that to a Baseline ventilation system created thru ASHRAE\'s Performance Rating Guidelines. Is this acceptable?" "The applicant is requesting confirmation about the modeling protocol for the project; however, not enough information has been provided to understand the unique aspects of the project. As a general rule, the applicant must model all buildings to meet all the requirements of ASHRAE 90.1-2004, Performance Rating Method, LEED-CSv2.0 EA Credit 1 requirements and LEED-CS v2.0 Appendix 2 - Core and Shell Energy Modeling protocol. For items out of owner\'s control, the parameters for the proposed and the baseline models must be maintained as identical. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2177" "2008-05-28" "New Construction, Schools - New Construction, Commercial Interiors, Core and Shell" "EAc1 - Optimize energy performance" "See below for treatment of District Thermal Energy systems in LEED-NCv2.2, LEED-CSv2.0, and LEED-CIv2.0." "USGBC has developed a document that clarifies how district or campus heating or cooling systems are to be treated in all Energy and Atmosphere prerequisites and credits for LEED-NC, LEED-CS, and SSc1, Options K & L under LEED-CI. That document is available for download from the LEED Reference Documents page, here: https://www.usgbc.org/ShowFile.aspx?DocumentID=4176. All LEED-NC, LEED-CS, and LEED-CI projects involving district or campus heating or cooling systems that registered for LEED after this posting date must follow that guidance, and such projects that registered before this date may optionally follow that guidance." "None" "None" "LEED Interpretation" "2194" "2008-09-18" "Core and Shell" "EAc1 - Optimize energy performance" "We are working on roughly 2 million SF of retail and office space spread over 30 buildings. This development is pursuing LEED CS in Las Vegas, NV. The project team is seeking information on modeling methodology for multiple buildings being certified under one submittal for Energy and Atmosphere Credit 1, Option 1. The LEED Application Guide for Multiple Buildings and On-Campus Building Projects states the following for EAc1: ""To receive a single rating for a group of buildings, use a weighted average for the group of buildings based on their conditioned square footage, or aggregate the data into one PRM calculation, so that the performance in achieved by buildings of varying sizes within a certifying group."" We are wondering if creating representative models for buildings with similar characteristics would be an acceptable approach. Each representative model would demonstrate the savings that we could anticipate for buildings with the same characteristics. A weighted average would then be taken of the results and the overall energy cost savings for the development would be calculated. We would carefully determine the number of representative models in order to truly make an accurate portrayal of each building on site. The number of representative models would be dependent on the similarities in building layout, size, construction, use, orientation, adjacencies, HVAC, lighting, and operation. For instance, one representative model would demonstrate the energy cost for all buildings on site with the same construction, use, orientation, adjacency, HVAC, lighting and operation. The baseline cases would adhere to ASHRAE Standard 90.1-2004, as per LEED requirements. Please let us know if the proposed representative modeling methodology is acceptable." "For a project comprising of 30 buildings with roughly 2 million sf of retail and office space, the applicant is enquiring, whether it is acceptable to model representative buildings in cases where a number of buildings have similar characteristics such as construction, orientation, adjacency, HVAC, lighting and operation. The modeling methodology as described by the applicant, however, is not acceptable. The applicant has stated as an example, that one building model would represent the number of buildings having similar above mentioned characteristics. A representative building may only be used if the buildings with similar characteristics outlined above also have identical footprints. In this case, the energy cost of one representative building may be multiplied by the number of identical buildings to get the total energy cost. If this is not the case then each building must be modeled separately.\n\nUpdate April 15, 2011: Please note that all 2009 projects in multiple building situations must follow the 2010 Application Guide for Multiple Buildings and On-Campus Building Projects, located here: https://www.usgbc.org/ShowFile.aspx?DocumentID=7987. 2009 project teams should check this document for up to date guidance on all multiple building issues. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2230" "2008-09-30" "Core and Shell" "EAc1 - Optimize energy performance" "This project is seeking a single LEED-CS certification for a mixed-use campus via multiple building approach. The Retail District will include roughly 1.6 million square feet of new construction. The following development summary represents the anticipated size and distribution of uses planned: Development Summary Residential Uses (31.3% Floor Area Weight) 511,200 sf Mix of town homes, row houses, apartments and condominiums in medium-density, high-rise and vertical mixed-use buildings; 4,000 - 6,000 estimated dwelling units The residential component planned for the site will be divided among for-sale and rental units of different sizes and price points. There will be town homes, row houses and live/work studios fronting onto residential streets and parks within the residential district. The mixed-use portion of the project will have lofts, apartments and condominiums in mid-rise buildings over retail and high-rise residential. Office Uses (8.5% Floor Area Weight) 138,194 sf Office over retail in a mixed-use setting Class A office building Existing office to remain Office space will likewise be available for a wide spectrum of users. The master plan envisions up to 3 million square feet of office space of various sizes ranging from small spaces over retail in the heart of the mixed-use core, to stand-alone class A office buildings. The master plan can accommodate up to a million square feet in a three building office complex at the northern portion of the site that would provide space for a single large corporate tenant or national headquarters. Retail Uses (32 % Floor Area Weight) 522,441 sf Restaurants & Entertainment Shop space in a mixed-use setting The retail planned will include department stores, a mix of national and unique retail shops, neighborhood services, restaurants and bars. Freestanding Retail Uses (13.9% Floor Area Weight) 226,673 sf Department store #1 Department store #2 Hotel Uses (14.3% Floor Area Weight) 233,500 sf Two - three hotels over retail in a mixed-use setting Total Building Areas 1,632,008 sf Per CIR 2/13/2008 ENERGY AND ATMOSPHERE: Optimize Energy Performance USGBC has an application guide for LEED-NC projects submitting multiple buildings in one application (http://www.usgbc.org/ShowFile.aspx?DocumentID=1097). This guidance can be used by Core and Shell projects when applicable. For EAc1, we can input the data for all buildings into one template. Per the letter of the document (the Application Guide for Multiple Buildings and On-Campus Building Projects, or AGMBC, that is), aggregate performance is required to achieve the 14% threshold required under EAc1 should a project choose to aggregate energy cost performance data. According to the language of the AGMBC, it is required that individually each building must only meet the requirements of EAp2, not the 14% threshold for EAc1. The project team is requesting confirmation on submitting the energy performance information for freestanding structures. If the individual retail-only core & shell buildings (13.9% Floor Area Weight) have less than 14% energy optimization but meet the ASHRAE 90.1, 2004 requirement (EAp1) can they be counter balanced by the aggregate calculations? Nevertheless with several buildings\' LEED status in the balance we need confirmation that this approach is acceptable especially for the freestanding retail buildings." "The applicant is inquiring whether each building in a campus setting must individually meet the 14% threshold for EAc1, provided each building individually satisfies the requirements of EAp2. The Application Guide for Multiple Buildings and On-Campus (AGMBC) allows projects with multiple buildings to demonstrate energy savings based on the aggregate of all of the buildings. Therefore, each building is not required to individually meet the threshold for EAc1.\n\nUpdate April 15, 2011: Please note that all 2009 projects in multiple building situations must follow the 2010 Application Guide for Multiple Buildings and On-Campus Building Projects, located here: https://www.usgbc.org/ShowFile.aspx?DocumentID=7987. 2009 project teams should check this document for up to date guidance on all multiple building issues. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2231" "2008-10-23" "Core and Shell" "EAc1 - Optimize energy performance" "We are designing a project that will be seeking LEED certification with DES supplied district cooling. The project involves a large capital expenditure and recovery for district cooling infrastructure. This capital recovery fee and subsequent maintenance fees from the district cooling significantly affect the price for delivered chilled water. We are requesting a CIR regarding the recently adopted Required Treatment of District Thermal Energy in LEED-NC version 2.2, Version 1.0 May 22, 2008. The question specifically relates to the third sentence of the section of the document below: Energy Model Implementation - Energy Rates Energy rates for both the proposed and baseline buildings must be identical to each other for the corresponding energy types, and are defined in the models as follows: Step 1 (Building stand-alone method) - energy rates for all non-DES-supplied energy are assigned using the normal ASHRAE and LEED modeling rules, using the local utility rate schedules as they would normally apply to the project building. ""All DES-supplied energy is modeled using the actual purchased energy rates if it is purchased from a third-party organization (i.e., private DES utility or municipal system)."" If the DES-supplied energy is not actually purchased, (i.g., if a single organization owns or operates both the DES and the satellite project building, or if the DES uses free qualifying renewable energy generated on-site), can we use approximations of local market rates as explained in the LEED-NC v2.2 Reference Guide? Our project includes substantial costs related to creating and building the infrastructure within our development to deliver the DES-supplied chilled water. Along with those costs, there are maintenance fees associated with the utility owned DES plant that are also included in the cost of the delivered chilled water to DES purchasers. The delivered price of chilled water, per ton-hour, is $0.2031 per ton-hour. This amount, however, includes Capital Recovery and Maintenance fees in the amount of $0.1094 per ton hour, which would make the actual manufactured purchased price for chilled water $0.0937 per ton hour. When modeling our buildings for this project, would there be a requirement to hold the cost model constant (Building Stand Alone Method) to include all fees ($0.2031 per ton hour), or can we exclude the Capital Recovery and Maintenance fees from our model. When modeling traditional mechanical systems, the capital (equipment) and maintenance costs would not be included in purchased electricity rates for local generation of chilled water. In order to make the energy-based cost comparison fair, those same maintenance and capital costs should be allowed to be removed from the DES energy model as well. The inclusion of capital and maintenance costs penalizes the DES systems unfairly when comparing them to other traditional systems in the energy modeling. What is USGBC recommended approach regarding this issue?" "The applicant is requesting that the capital recovery and maintenance fees for DES-supplied chilled water be excluded from the purchased energy rate. The actual purchased energy rates must be used to model the DES-supplied energy costs per the LEED reference document identified in the request (https://www.usgbc.org/ShowFile.aspx?DocumentID=4176) since the project purchases DES-supplied energy from a third-party organization. The actual purchased DES energy rate is the delivered price of the chilled water (i.e., $0.2031 per ton-hour), which includes capital recovery and maintenance fees. The applicant does not seem to understand the DES guidance document. In the situation that has been mentioned (Step 1), the energy source is modeled as purchased energy (same rate) in both the baseline and proposed cases. Therefore, the DES is cost neutral, and the capital and maintenance costs should not penalize the DES system. In Step 2 (to determine EAc1 points), the DES is modeled as a virtual (on-site) plant in the proposed case and compared to a code-compliant on-site plant in the baseline case. In this scenario, the purchased rates are not used in either the proposed or baseline cases. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2242" "2008-10-03" "Core and Shell" "EAc1 - Optimize energy performance" "Our project is a 19,000 sq.ft., one-story retail shell building in Oro Valley, Arizona, registered under LEED for Core and Shell V.2.0. Unfortunately, the project was already fully designed when the owner decided to seek a LEED Certification. In this building, we expect to have six to ten retail tenants in the building. The project expects to begin construction in July and be occupied sometime in the fall of 2008. Since the LEED for Retail program is not accepting any new applicants and appears to be unlikely to release a final version before the end of 2008, we are left with some not very good options for meeting the LEED EAp1. As it stands, the current LEED-CS Reference Guide is way out of date and cannot be used easily to cover this type of project. In this type of ""vanilla shell"" building, the owner is providing about 12 rooftop HVAC units, but tenants are responsible for providing lighting and lighting controls. We have integrated LEED-specific tenant build-out requirements in the tenant leases, based on the ASHRAE Advanced Energy Design Guide (AEDG) for Small Retail. Currently, the LEED for Retail rating system version 2, pilot program, allows the use of the AEDG for Small Retail for meeting EAc1. Specifically, we propose to ""Comply with the prescriptive measures of ASHRAE Advanced Energy Design Guide for Small Retail Buildings 2004,"" to achieve the two-point minimum under EAc1. As it stands, the only other (non-modeling) compliance option, found as Option 3 of the LEED-CS Reference Guide, is out of date and cannot be used for any project. Therefore, it seems logical in retail projects such as this one, to use the AEDG for Small Retail instead. Based on our current assessment, this project is likely to meet the requirements for LEED Silver certification. An earlier Credit Interpretation Ruling for EAc1, dated 2/22/08, appears to rule out the use of the AEDG for Small Office for office projects with a retail component. However, the CIR didn\'t specifically deal with an all-retail project and the possibility of using the ASHRAE Small Retail guide. The AEDG for Small Retail is currently the best (and in some cases the only good) option available for meeting the EA1 prerequisite in this type of core and shell retail project and for assessing compliance with the EA1 standards. Therefore, we propose to use the prescriptive path in the AEDG for Small Retail buildings, since it will yield approximately the same energy savings results as the AEDG for Small Offices, but is more appropriate for this type of core and shell retail building." "The applicant requests the capability to use the prescriptive compliance path, Option 2, in LEED for Retail to document compliance with EA Credit 1 in LEED-CS. This prescriptive compliance approach is acceptable if the project team can document that the following requirements, along with all other requirements reflected in the Draft version of LEED-NC for Retail Version 2 (October 2007) are met: " "None" "None" "X" "LEED Interpretation" "2247" "2008-08-26" "New Construction, Schools - New Construction, Core and Shell" "EAc1 - Optimize energy performance" "The project is a major renovation of primarily the common areas in a 37-year old, one and two story, multi-tenant retail mall. The mall was originally designed, permitted and built as an open air mall where the tenants were grouped into multiple buildings with common areas open to the sky between them. During the 1980s, these common areas were enclosed using separate structural and mechanical systems. The total building area inside the LEED boundary is 500,575 sf. The common areas encompass 145, 282 sf. The tenant areas are aggregated in sectors from 20,000 sf to 50,000 sf and separated by one and two hour fire rated exit corridors (the common area of the mall). Both the common and tenant areas of the mall are independently conditioned with multiple small, air-cooled, roof-top systems ranging from 1 to 20 years of age. One of the main goals of the project is to decrease the building\'s energy and carbon footprint by incorporating an extensive HVAC upgrade package to the common areas and requiring all new leases to incorporate sustainable guidelines including HVAC equipment that exceeds ASHRAE 90.1. Question: Will it satisfy the requirements of CS EA Prerequisite 2 and EA Credit 1 to classify the tenant spaces and common areas of an existing multi-tenant retail mall as separate adjacent buildings similar to the requirements found in the LEED for Multiple Buildings under NC v2.2 for the purposes of determining the baseline HVAC system type(s) as defined in ASHRAE 90.1 Table G3.1A? Proposed Interpretation: The design team proposes to classify each tenant sector and the common area as separate campus buildings at the location of the fire rated partitions for the purposes of establishing the baseline HVAC system type. This would allow the baseline HVAC system types for the tenant areas (75,000 sf &" "The applicant is requesting clarification regarding the term ""building"" as it applies to energy efficiency modeling for a multi-tenant retail mall that was previously converted from an outdoor mall to an indoor mall with indoor common areas. From the description provided above, it appears that the retail mall should be classified as a single building: the common areas are directly connected to all of the retail spaces and/or the retail spaces are connected to one another; significant transfer of air is likely between the retail spaces and the common area spaces; and the use of the building (as a retail mall) is consistent throughout the whole project. There was no strong justification provided by the applicant to justify why the retail spaces should be considered as separate buildings. Therefore, the project should be considered a single building. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2249" "2008-08-26" "New Construction, Core and Shell, Schools - New Construction" "EAc1 - Optimize energy performance" "This project is a commercial office building located in New York City on a uniquely shaped parcel of land. The building is located on an asymmetrical triangular shaped lot of 5,549 sq. ft. While the building is six stories tall, the total square footage of the building is only 34,300 sq. ft. This type of building is quite unique to dense urban areas in making the most of a small lot. Due to the fact that this building is unique in terms of its height in comparison as compared to its sq footage, this CIR is asking if an allowance can be made to use a more comparable baseline per ASHRAE 90.1-2004 in the energy model. The following are the baseline building types outlined in ASHRAE 90.1-2004 for selection of Baseline HVAC System Types: - Residential - Nonresidential & 3 floors or Less & < 75,000 sq. f.t or 5 Floors or Less & 75,000 sq. ft. to 150,000 sq. ft. - Nonresidential & More than 5 Floors or >150,000 sq. ft. Per these requirements this small 34,300 sq. ft. building would be using the same baseline system descriptions as significantly larger facilities. We are proposing that because of this discrepancy that the third option of Nonresidential & 4 or 5 Floors & < 75,000 sq. f.t or 5 Floors or Less & 75,000 sq. ft. to 150,000 sq. ft. be a viable baseline for the project to use in the energy model. The systems that differ between the two baselines are as follows: Nonresidential & 4 or 5 Floors & < 75,000 sq. ft. - System 5 Packaged VAV w/ Reheat OR System 6 - Packaged VAV w/ PFP Boxes Nonresidential & More than 5 Floors or >150,000 sq. ft. - System 7 VAV w/ Reheat OR System 8 - VAV w/ PFP Boxes." "The applicant requests an exception to ASHRAE 90.1-2004 Appendix G modeling methodology that would allow the project to model a Baseline HVAC system type that more closely reflects the system type used for similarly-sized buildings. While the project\'s efficient use of land is commendable, the CIR process cannot be used to grant exceptions from ASHRAE modeling requirements. The project team must model the building using the applicable system type determined from the system mapping in Table G3.1.1A. Since the project is less than 100,000 square feet, the project team may opt to document credit compliance using the Option 3 prescriptive compliance path (the Advanced Buildings Core Performance Guide) rather than the Option 1 Whole Building Simulation compliance path. However, if the whole building simulation compliance path is selected, the project must follow all applicable ASHRAE Appendix G modeling protocol. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2349" "2008-10-24" "New Construction, Core and Shell" "EAc1 - Optimize energy performance" "The project is a 400,000 SF office building. The building structure and core spaces (stairwells, elevators, etc.) will remain. A new building envelope (skin) on the south and east elevations will be provided. Existing exterior walls will remain on the north and west elevation, with new insulation and windows. The majority of existing building systems will be replaced, with the following exceptions: - There are two existing chillers, one will be replaced and one will remain - Existing mechanical, storm, sanitary, and fire protection pipe risers will remain - The existing garage ventilation system will remain Since we are reusing the building structure, which limits some of our energy reduction strategies (building orientation, daylighting, etc.), and also salvaging existing exterior walls, mechanical equipment, and piping, we feel that we should qualify as an Existing Building Renovation. Please clarify if this assumption is correct." "The project team is requesting guidance to classify the project as an Existing Building Renovation. Due to the large portion of the building and systems excluded, this is acceptable. However, care must be taken to follow the requirements of ASHRAE 90.1-2004 Appendix G, as specific requirements for modeling existing building portions must not be ignored. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2352" "2009-02-03" "Core and Shell" "EAc1 - Optimize energy performance" "The project is a large mixed use complex which will include several buildings: 1. Building A, which consists of a retail base of 101,000 square feet (SF). It is connected to the other buildings only thru a utility corridor below grade. 2. Building B, which consists of a retail base of 88,000 square feet (SF) under a 175,000 SF high rise residential tower. It connects to the loading dock thru a small area on the lower level. 3. Building C, which consists of a retail base of 125,000 square feet (SF) and a 80,000 SF theatre/entertainment complex. It connects to the loading dock thru a small area on the lower level. 4. Building P, which consists of a 403,000 SF, 7 level, aboveground parking facility and a 30,000 SF below ground loading dock with ancillary support spaces. Building P shares a common wall with building B and another with building C. The design team has determined that it is feasible to certify buildings A, B and P. Because building P is adjunct to building B it is proposed to include this building with building B since there is no provision to certify an un-heated parking structure independently. This was accepted in a previous correspondence with USGBC. Thus there will be 2 separate certifications, one for building A and one for building B and P. The proposed HVAC system for the majority of the complex is a closed loop heat pump system. Each space will be provided with condenser water and will provide its own heat pumps. Because heat pumps are not effective at treating outside air it is expected that they will be used primarily to offset skin losses, while electric resistance heat is used to temper ventilation air. A central plant will be located in building C, with cooling tower, pumps, heat exchangers and auxiliary heat source to circulate water for use by heat pumps in building A, B, C and the lower level of P. Building D is not planned to be served by the central system due to the nature of the occupancy. The question to be verified is as follows: The central condenser water distribution does not constitute a district energy system, since it provides only a heat sink for the heat pump units which generate the heating and cooling for the spaces. It does have one similarity to a district energy system in the sense that there is energy consumed at the central system which is serving multiple buildings. However, unlike a district energy system, the energy consumed at the central system is only a small portion of the energy used for heating and cooling. Based on the above, it is requested to use the approach of modeling downstream energy equipment in each building based on using condenser water from the central system and modeling the portion of energy consumed by the central system based on a virtual central system sized only for the building modeled. The central condenser water system for the proposed design would be modeled based on electric resistance as the auxiliary heat source. The baseline buildings would be modeled for system 6 for the commercial areas (less than 150,000 SF, all electric) and system 2 for the residential areas. The owner would consider using gas boilers for the auxiliary heat source at the central plant, reducing total energy cost for the project, but would likely not do this if it was interpreted that this requires modeling the baseline systems as systems 5 and 1 respectively. We request that this decision of improving the central system energy cost not impact the energy modeling of the individual buildings, since the decision of how to construct the central system is separate from the design of the individual buildings which are being certified. Again, the requested modeling approach is for the proposed design would use electric resistance heating for the auxiliary heat source in the virtual central system to provide a fair comparison against systems 6 and 2 in the baseline model. Please confirm acceptability of the above approach." "The project team is requesting guidance on a proposed modeling approach, as well as baseline system type selection. As stated, the project should treat the central system much in the same way as a District Energy System, in which a virtual central system is modeled for each building onsite. For more guidance on modeling procedure, please see http://www.usgbc.org/ShowFile.aspx?DocumentID=4176. This document also gives guidance on appropriate baseline systems. Regarding the question of baseline system selection, an earlier NCv2.2 EAc1 CIR dated 9/27/2006 allows for a Baseline system to be specified under the ""Electric and Other"" category though equipment uses natural gas under some circumstances, as long as the modeling does not ""attempt to take credit for natural gas heating versus electric heating."" If electric resistance auxiliary heating is used in the proposed virtual system, systems 2 and 6 can be used for comparison. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2550" "2009-04-14" "New Construction, Schools - New Construction, Commercial Interiors, Core and Shell" "EAc1 - Optimize energy performance" "Background: Our project is a 3 story, 16,500-sq.ft. addition to an existing 3 story, 84,000 sq.ft. building. The existing building is predominately laboratory space with some office space. The addition will be of similar use. The heating and cooling of the existing building is served by a central utility plant which provides chilled water and hot water via a steam boiler and heat exchanger. It is proposed that the addition also be served by the central plant. The central plant serves several other buildings on the site as well. In order to make a decision on whether we would like to obtain LEED registration on just the new addition or on the entire building with the new addition, a preliminary building simulation is being modeled. For the ASHRAE baseline, the system is modeled as a ""System 3 - PSZ-AC"" (packaged rooftop, constant volume, direct expansion, and fossil fuel furnace) per table G3.1.1A of ASHRAE 90.1-2004. Though the combined building size would categorize building with addition as a ""System 5 - Packaged VAV w/ Reheat."", section G3.1.1(c) mandates conforming to the requirements of System 3 as an exception due to the special pressurization relationship/ cross-contamination requirement of the laboratory. Interpretation Request: Little is stated in ASHRAE 90.1 2004 on the most appropriate way to model a system that has chilled water and hot water heat supplied from a central plant. However, there are a few CIRs concerning similar circumstance that allude to it such as the 1/27/2004-2/24/2004 EA1.1 CIR. In it, it is stated that ""While the situation described is not using purchased chilled water or steam, this HVAC description for the budget building is the closest to the proposed design and should be used for the energy modeling purposes."" This approach for the budget building model is quite workable since the building owner has costs available for both chilled water and heating hot water. However, the baseline is modeled as a DX cooling and gas fired furnace. Is it appropriate to model the budget building with chilled water and heating hot water, when the baseline model is using neither of these? If not, how should the baseline and budget building be modeled?" "The applicant is requesting clarification regarding modeling methodologies for projects which include a central utility plant. Note that the USGBC published a document titled ""Required Treatment of District Thermal Energy in LEED-NC version 2.2 and LEED for Schools"" in May of 2008 located at the following website: http://www.usgbc.org/ShowFile.aspx?DocumentID=4176 Please refer to this guidance document, which is also referenced in a CIR dated 5/28/2008. Also note that the exception in ASHRAE 90.1-2004 Section G3.1.1 Exception (c) is only applicable for zones that have special pressurization requirements. All zones of the building or addition that do not meet the exception requirements must be modeled using System 5 - Packaged VAV w/ Reheat in the baseline. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "282" "2001-09-05" "New Construction, Schools - New Construction, Core and Shell" "EAc1 - Optimize energy performance" "For the Blanchard College Center project, we are asking the USGBC to clarify the criteria for declaring whether a building is New or Existing in relation to the available points for this credit. In the specific case of the Blanchard College Center, the project is primarily a gut renovation of an existing historical facility, to which two new additions will be added. The area of the existing facility is approximately 33,403 s.f. The area of the two additions totals approximately 13, 885 s.f. The additions therefore represent approximately 29.4% of the total building area. From a systems standpoint, approximately 95% of the existing shell will be reused, however, there will be new furring/insulation for the walls and roof, new lighting, and new mechanical systems. We are assuming that this facility qualifies as an existing building, primarily because the existing facility represents the majority of the overall square footage of the project. In addition, the efforts to preserve the form and shell of the existing building has restricted the designer opportunities to pursue more aggressive energy reduction strategies (e.g., building orientation, daylighting/ventilation strategies, high performance envelope, etc.). Please clarify that this is the correct assumption for this project." "THIS LEED INTERPRETATION HAS BEEN REVISED AS OF 9/21/06 TO PROVIDE A CALCULATION THAT IS MORE WIDELY APPLICABLE (AND IS EQUIVALENT FOR THIS SCENARIO). To calculate the optimization point table for a project that has both existing and new construction, use the following formula for each line of the table: target percent = (existing SF / total SF) * (existing percent) + (new SF / total SF) * (new percent) *This equation applies to LEED NC v2.0, v2.1, and v2.2 and LEED CS v2.0 ORIGINAL LEED INTERPRETATION 9/5/01: To calculate the optimization point table for a project that has both existing and new construction, use the following formula for each line of the table: existing percent + ((new SF / total SF) * 10) = target percent. Applicable Internationally." "None" "None" "X" "LEED Interpretation" "3300" "2003-03-11" "New Construction, Core and Shell, Schools - New Construction" "EAc1 - Optimize energy performance" "ASHRAE 90.1 does not allow credit for air leakage reduction. However, it does indicate that windows are allowed to have 1 cfm per square foot air leakage (at 0.30"" water.) The windows we are using in this project are very high performance, with significantly lower air leakage rates. The manufacturer has supplied test results indicating the tested air leakage rate. Further, we are using a blower door and infra-red camera simultaneously to locate and seal any air leaks in the window system that result from installation. We propose to take credit for this air leakage reduction, with the following methodology:\n\nThe tested air leakage rate at 0.30"" can be established for the windows as installed, based on manufacturer\'s data, and for the base case windows based on ASHRAE 90.1. Both these values will be extrapolated to expected winter heating season air leakage rate, using the LBL correlation for blower door test data. We have run two blower door tests, and will use the most recent (during which most of the air leakage has been taken care of) test data to establish the relationship between the air leakage rate at 0.30"" static pressure (75 Pa) and the average heating season air leakage rate, which is calculated at the building pressure established by the LBL correlation, which is based, in part, on the exposure of the building to wind. In this case exposure is significant, as the building is fully exposed on the west side of the building to windows ranging from south to west to north.\n\n We then propose to run the base case building, in the energy modeling, using TRACE, with the air leakage rate for the windows established in the above manner. The building as built would be modeled with zero air leakage rate. Preliminary estimates indicate that the difference in overall extrapolate natural air leakage rates in 0.04 air changes per hour, at typical heating season winter conditions.\n\n Blower door guided air leakage reduction: A significant effort at air sealing is part of the energy saving strategy for this building. With the location noted above, air leakage reduction is particularly important. Two blower door tests with simultaneous infrared scanning, have been completed. The first identified a number of areas that were not complete as designed. Most of these were completed by the time of the second test, and a number of areas were identified during the second test that, in my opinion, would not have subsequently been air sealed had this procedure not been in place. A list of further items was developed from this second air leakage test, and this list has been circulated by the GC to responsible parties, who will sign off when they have completed the items. When those items are complete, a third, and hopefully final, blower test will be conducted.\n\nWe propose to take credit in our energy calculations for the air leakage reduction between the second and third blower door tests, using the LBL correlation to extrapolate to typical heating and cooling season air leakage rates, as described in number 2 above. The extrapolated seasonal air leakage rate reduction would be applied to the base case building. For example, if the extrapolated air leakage reduction were 0.1 heating season air changes per hour from blower door test #2 to test #3, we would assign 0.1 ACH to the base case building and zero air leakage to the building as built.\n\nWe feel that this third round of testing and air leakage reduction is well beyond typical attention paid to air leakage, that air leakage control is particularly important in this very cold (7700 degree-day) climate and at this exposed site, and that we have demonstrated a method using accepted principals to quantify the savings. Blower door test results and LBL correlation spreadsheets for each test would be provided as part of the submission. We would also submit the list of items to be air sealed as part of the final air leakage reduction package.\n\n Windows and air leakage reduction together: We propose to add the two air leakage reductions - from window improvements and blower-door-guided air leakage reduction. For example, if the blower-door-guided heating season air leakage rate reduction were 0.1 ACH and the window air leakage reduction were 0.04 ACH, the base case building would be modeled at 0.14 ACH and the building as built at 0.0 ACH.)" "Advanced air sealing is a strategy that can lead to measurable energy savings, particularly in cold climates. Although this measure is outside the scope of ASHRAE 90.1 modeling protocol, you may be able to make a case for the significance of this strategy in improving energy performance. However, this will require clear and thorough documentation in order to be considered under the requirements of this credit.\n\n The following guidelines are provided to help strengthen your approach:\n\n(1) Provide manufacturer\'s air leakage test results that use the same testing protocol as that by which ASHRAE identified the baseline for window air leakage.\n\n(2) Use a typical infiltration rate as a baseline, and reduce it by the amount of improvement you can document or estimate from the air sealing strategies employed. Do not use zero infiltration in the model, as this is not a realistic assumption. A zero infiltration strategy would over-emphasize the percentage of overall energy use reduction represented by infiltration improvements.\n\n(3) Include required fresh air ventilation rates (per ASHRAE 62) in both the proposed and baseline model results.\n\n(4) Provide clear documentation of air sealing strategies and blower door test results, corrected for wind and temperature effects, to clarify anticipated air sealing performance.\n\n(5) Provide documentation which clarifies the percentage of energy savings attributed to the air sealing strategy, as opposed to other energy performance measures incorporated into the building.\n Applicable Internationally. \n\n **Updated January 1, 2014\n Advanced air sealing is a strategy that can lead to measurable energy savings, particularly in cold climates, though its effectiveness is especially dependent on the quality of construction and cannot easily be predicted during the design phase. Recognizing this, the ASHRAE 90.1 committee developed Addendum ag to Standard 90.1-2010, which establishes guidelines for claiming energy savings that result from reduced infiltration in Appendix G. The approved change allows credit only for buildings that complete envelope pressurization testing in accordance with ASTM E779. The appendix establishes a baseline air leakage rate of 0.40 cfm/ft2 (2.03 L/s•m2) at 0.3 in. wc (75 Pa) pressure differential compared to the measured leakage results in the proposed building.\n\n Projects wishing to claim energy savings from advanced air sealing may do so given they meet the following requirements:\n\n 1. Utilize Addendum ag to Standard 90.1-2010 to document savings.\n\n 2. Provide clear documentation of air sealing strategies and air leakage results from ASTM E779-10 Standard Test Method for Determining Air Leakage Rate by Fan Pressurization, including confirmation that all testing criteria defined in the standard have been met.\n\n 3. Provide documentation that clarifies how energy savings from reduced air leakage has been estimated from the ASTM E779 test results and identifies the percentage of energy savings attributed to the air sealing strategy, as opposed to other energy performance measures incorporated into the building. " "5060, 5691, 5456, Update LI 3300 Applicable Credits" "None" "X" "LEED Interpretation" "5027" "2007-01-08" "New Construction, Schools - New Construction, Core and Shell" "EAc1 - Optimize energy performance" "For our project, a high rise condominium tower, we are considering providing at move-in, full coverage, insulated, automated blinds on the interior of the building as part of the energy use reduction design strategy. These blinds will be built-in, non-optional, and fully automated with a manual override to allow occupants to override the automatic settings. The alternative would normally be owner provided blinds with a wide range of characteristics, but not likely to include the heavy, insulated blinds envisioned by this energy measure. We are considering sizing the design cooling and heating so that comfort can be maintained most effectively by using the blinds. Cooling reduction will probably include some venting between the fenestration and the interior blinds so that heat that enters the glazing does not stay in the space. Can we take credit for automatic shading by using the DOE2.2 shading inputs so the energy impacts are integrated with the rest of the model? ASHRAE 90.1-2004 Appendix G indicates that manual shades and blinds not be modeled in the baseline or the design. Automatic blinds or shades can be modeled for the design, and the baseline description does not say if these are to be modeled or not. For this energy measure, variations in model schedules between the design and baseline, with clearly stated assumptions and documentation, would be the appropriate way to model the difference in the operation of blinds between the design and baseline. Other inputs would account for differences in the design blinds and typical owner blinds including R-value, and shading coefficient. Please clarify whether we can capture the efficiency benefits of this strategy within our EAc1 model, and if so, the modeling requirements per the questions above and any other factors that might apply." "The project team is seeking clarification regarding how to document the savings achieved from automated shading. ASHRAE 90.1-2004 Appendix G does allow credit in the Proposed Building model for automated shading devices, including automated blinds. No manual or automated window shading devices should be modeled in the Baseline Building model. If the energy software does not have the capability to model automated shading devices, the assumptions used for defining automated shading schedules should be clearly documented. Also, if the automated shading devices include a manual override for user control, the assumptions regarding percentage use of the automated controls should be clearly stated. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5037" "2008-06-20" "New Construction, Core and Shell" "EAc1 - Optimize energy performance" "We are requesting clarification regarding what percentage of a building must be open 24 hours for the building to be considered a 24-hour facility. ASHRAE 90.1-2004, Section 6.5.6.2 requires condenser heat recovery for preheating service hot water for facilities operating twenty-four hours per day, when the total installed heat rejection capacity of the water-cooled systems servicing the building exceed 6,000,000 Btuh, and the design service water heating load exceeds 1,000,000 Btu/h. Our project is a large retail complex which most likely exceeds the total installed heat rejection and service water heating loads listed. However, only 17% of the complex (a large arcade facility) is open 24 hours per day. The rest of the complex will be closed for a portion of each day. We believe we are exempted from the heat recovery requirement since the domestic water heating loads are mostly coming from the areas of the building that are not open 24 hours, and since only a fraction of the complex is open 24 hours per day. We would like confirmation that our interpretation is correct." "The applicant is asking to confirm their interpretation of a specific ASHRAE 90.1-2004 requirement. Based on the description provided, if the project is served by a single system, it should be considered as a 24 hour facility. If the system used for the conditioning of only the 17% of the complex (open as a 24 hour facility) does not meet the heat rejection or service water heating requirement, it would be exempt from the requirements of ASHRAE 90.1-2004, Section 6.5.6.2. Table G3.1 section 11 of ASHRAE 90.1-2004 describes the modeling requirements for service water heating systems including those covered by ASHRAE 90.1-2004, Section 6.5.6.2." "None" "None" "LEED Interpretation" "5038" "2007-02-07" "New Construction, Core and Shell" "EAc1 - Optimize energy performance" "We are requesting clarification regarding what percentage of a building must be open 24 hours for the building to be considered a 24-hour facility. ASHRAE 90.1-2004, Section 6.5.6.2 requires condenser heat recovery for preheating service hot water for facilities operating twenty-four hours per day, when the total installed heat rejection capacity of the water-cooled systems servicing the building exceed 6,000,000 Btuh, and the design service water heating load exceeds 1,000,000 Btu/h. Our project is a large retail complex which most likely exceeds the total installed heat rejection and service water heating loads listed. However, only 17% of the complex (a large arcade facility) is open 24 hours per day. The rest of the complex will be closed for a portion of each day. We believe we are exempted from the heat recovery requirement since the domestic water heating loads are mostly coming from the areas of the building that are not open 24 hours, and since only a fraction of the complex is open 24 hours per day. We would like confirmation that our interpretation is correct." "The applicant is asking to confirm their interpretation of a specific ASHRAE 90.1-2004 requirement. If the capacity that serves the 24 hour facility (described as 17% of the project) is below the ASHRAE defined limits for installed heat rejection capacity and service hot water heating loads, then the project does not need to follow the requirements of ASHRAE 90.1-2004 Section 6.5.6.2. If the capacity is greater than the defined limits, then the project must follow the requirements." "None" "None" "LEED Interpretation" "5060" "2007-07-09" "New Construction, Schools - New Construction, Core and Shell" "EAc1 - Optimize energy performance" "ASHRAE 90.1 sets specific requirements for the building envelope, including meeting all requirements of Section 5.4. Air Leakage, Section 5.4.3, requires sealing, caulking, gaskets and weather stripping of the building envelop to minimize air leakage. For the Barkesdale Dormitory, additional methods were used to minimize air infiltration. Additional barriers, taping, and low leakage panels per ASTM E283-84 (0.06 cfm per square foot of fixed wall at 63.3 mph wind and 1.92 iwg.) were used. Additionally, the building was pressurized to prevent infiltration. A baseline building model is neutral with average construction. With the value added benefit of additional barriers, taping and low leakage panels and pressurization, the Barkesdale Dormitory can be considered a ""tight-pressurized construction"". These differences could effect the energy calculations. Is this a logical conclusion?" "This CIR seeks to use reduced infiltration rates from a superior building envelope as a variable in the energy cost budget calculation for optimizing energy efficiency. The ASHRAE modeling protocol does not allow the infiltration rate to be changed between the budget and the design case. The CIR ruling of 3/11/2003 for EAc1.2 provides some guidelines on how a case might be made for advanced air sealing. The methodology proposed for this project does not address all the issues raised in that ruling and would be insufficient to grant an exception to the modeling protocol. Applicable Internationally. " "3300, Update LI 3300 Applicable Credits" "None" "X" "LEED Interpretation" "5072" "2007-11-14" "Core and Shell" "EAc1 - Optimize energy performance" "Central Park East (CPE) is a 26 story office building with retail on the first level, 9 floors of parking above the retail, and approximately 490,000 sf of office above the parking area. This development is a very unique development, particularly in downtown Phoenix, which has not seen any major new office buildings in nearly fifteen years. Our project is building on an existing surface parking lot in downtown Phoenix, is adjacent to the Arizona State University downtown campus and is directly across the street from the Valley Metro Rail and Regional Public Transportation Authorities downtown bus hub. We began the design of the CPE project in its current state in early spring of 2006 and are going to break ground in early October of this year. The overall building design and in particular the MEP and building enclosure systems, were designed to meet specific requirements of the LEED-CS program as it stood in early 2006 with the full intent to pursue certification. The issue that we are now facing with regard to CPE is that we did not register the CPE project prior to the June 26, 2007 rating system change which now requires the (2) Optimize Energy Performance credits. Unfortunately for our project, we are now up against a wall. Based on our timing for groundbreaking, a number of the scopes have already been bought and released. The primary challenge we are facing is that a redesign and scope modification to meet the new requirements would be extremely costly and would impact our schedule substantially. As designed, we currently exceed the performance requirements of ASHRAE 90.1-2004 Chapter 11 for the Energy and Atmosphere Prerequisites; the building exceeds energy requirements by 4% and costs by 10%. Since we are not able to meet the specific requirements of the now required (2) Optimize Energy Performance credits, we would like to propose an alternate plan to achieve the 14% cost savings for the building. Based on the whole building energy simulation under appendix \'G\' , we are operating at 97% of ASHRAE 90.1-2004, leaving us with a deficit of 17%. We propose to close this 17% gap with the following methods: -Require tenants through the lease(s) to design to no greater then 0.9 Watts/SF for their lighting build out. This will result in a minimum increase in energy performance of 2.6%. -Switch ""high efficiency"" motors to ""premium efficiency"" motors. This will result in a minimum increase in energy performance of 1.0%. -The balance of the energy optimization, 13.4%, to get to the +14%, will be handled through the purchase of energy from a renewable source(s) as defined by the Center for Resource Solutions (CRS) Green-e product certification requirements for the life expectancy of the building (50 years). We did also review the use of the higher efficient coolant (R-22) in the water cooled Dx system designed for this project. This would have increased the energy efficiency of the building by approximately 4.7%, however, there are considerable environmental and longevity concerns with using the R-22 coolant. Therefore, this option was not pursued beyond the initial study. In addition, we also studied the installation of a 50kw -150kw photo voltaic array on the roof of the building. Due to limitations of available roof area, high perimeter parapets and shading through the winter and partial spring and fall by a taller building to our south, we were not able to effectively design a viable PV array on the roof of this building. Building a sustainable building and obtaining LEED-CS certification for our CPE project is very important to our team , future tenants and public at large; we really want to make this happen. Although the above proposal does not necessarily meet the exact intent of the recent LEED - CS 2.0 requirement of two Energy Performance credits, we feel that based on the timing of our design, trade buyout, and groundbreaking for the project, that the same end goal will be achieved." "The applicant is requesting clarification regarding an acceptable method for achieving the 2-point LEED EAc1 minimum requirement for a LEED-CS project exceeding 100,000 square feet, where the systems included in the Core & Shell Design contribute only a small percentage towards the total energy that will be consumed by the building. The applicant proposes an alternate compliance method that includes a combination of Core & Shell building efficiency improvements, tenant leasing efficiency requirements, and Green Power purchase to achieve the 2-point minimum requirement. It is acceptable for the project team to use Core & Shell building efficiency improvements, tenant leasing efficiency requirements, and/or site-generated renewable power (pursuant to the requirements stipulated by the rating system) to achieve the minimum energy performance requirements. However, Green Power purchase may not be used towards achieving points under EAc1. The LEED-CS errata for EAc1 (dated November 2, 2007) allows a project to meet the EAc1 credit requirements by incorporating tenant sales or lease agreements requirements as part of the tenant scope of work. Credit for these efficiency requirements can be reflected in the EAc1 energy model. For example, if tenant sales and lease requirements state that the installed lighting power density may not exceed 0.9 Watts per square foot in an office building, this may be modeled for credit in the energy analysis ( please reference the LEED-CS Errata: http://www.usgbc.org/ShowFile.aspx?DocumentID=3203 for details). Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5085" "2008-08-26" "New Construction, Schools - New Construction, Core and Shell" "EAc1 - Optimize energy performance" "We are proposing a 180,000 sf office building in Austin, TX that is tying into an existing Austin Energy District Cooling loop. This chiller plant is part of a larger campus that is being changed over from a manufacturing and office campus to a multi-use development. The was designed to achieve an Austin Energy Green Building (AEGB)commercial 2-star rating, but the goal was changed to LEED-CS since the AEGB program does not include provisions for Core and Shell projects. Upon switching over to LEED-CS, it was discovered that the energy efficiency minimum had changed. In modeling the building to determine if we could meet the revised minimum energy efficiency, we found that the baseline we are to compare to per ASHRAE 90.1-2004 Appendix G is the same as our proposed building: district cooling. As a result, the inherent efficiencies found in the district cooling system are lost, unless we construct our own chiller as part of this project. Given that lighting, process, and plug loads must also be equivalent in the baseline and proposed cases, it is very difficult to see reasonable efficiency percentage changes, even with the most efficient envelope and heating systems. Their overall percentage effect on the total energy use is too small to make the 14% reasonably achievable as a minimum efficiency. Based on discussions with similar project teams in the area, our situation is not unique. What we are requesting is either that: 1. The baseline is revised such that the use of an existing district chilling plant is not penalized. We feel that the intent of the current baseline is to encourage sustainable energy use on a holistic level, not to encourage individual projects to build their own chiller plants. 2. The minimum percentage be revised for such Core & Shell scenarios where areas in which there are opportunities for improvement in energy efficiency are minimal." "The applicant is requesting clarification on the LEED-CS v 2.0 requirements for energy analysis. For the proposed design using purchased chilled water, the design must use the actual utility rate for the purchased chilled water. The baseline model must use chillers designed to meet all requirements of sections G3.1.3.7 and related sections of ASHRAE 90.1-2004 Appendix G. The inherent efficiencies in the central plant are accounted for in the cost of the chilled water versus the cost of electricity to generate and circulate the chilled water on site. Please also see the document titled, ""District Thermal Energy Treatment"" on USGBC\'s website (http://www.usgbc.org/ShowFile.aspx?DocumentID=4176). This may also be used as an acceptable modeling compliance path. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5110" "2008-02-11" "Core and Shell" "EAc1 - Optimize energy performance" "The project is a speculative office highrise building, where the Owner will rent floors, or portion of floors, to multiple tenants. The owner will supply Core & Shell HVAC equipment including a central boiler plant, floor-by-floor water-cooled DX equipment, and cooling towers that serve the owner-provided DX units and any supplemental tenant-installed DX units for data rooms, etc. The owner also provides lighting for the Core and Shell spaces (public lobbies, elevators, bathrooms, garage). The tenants provide all partitions, HVAC distribution, appliances, equipment and lighting in their areas, and any supplementary DX equipment mentioned above. We want to clarify whether the calculations for percentage of energy cost savings under LEED-CS EAc1 should be performed using the total energy cost of the building, or only the energy cost for the Core & Shell. PROPOSAL: We propose to calculate the percentage savings as follows: 1. Model the energy consumption for the entire building > For the Design Model, model the building envelope, the Core & Shell areas, lighting, elevators, plug loads and any other equipment controlled by the Owner according to the design. For the Baseline Model, create a model that complies with the requirements of ASHRAE/IESNA Standard 90.1-2004 Appendix G. > Since tenants are unknown, assume that the lighting in tenant spaces of the Design Model is in accordance to the requirements of the ASHRAE/IESNA Standard 90.1-2004 -- the same as in the Baseline Model. > Assume that the plug loads in the tenant spaces of the Design Model is the same as in the Baseline Model. The plug loads will be no less than 25% of the electricity use of the Design Model. 2. Calculate the energy cost for the entire building - both Design and Baseline models 3. Calculate the energy cost paid for by the tenant, i.e., for uses over which the tenants have control. This energy use is identical for both the Design Model and the Baseline Model: > Lighting in tenant spaces > Plug loads in tenant spaces > Any DX equipment installed by tenants in their spaces 4. Subtract the cost of tenant-controlled energy use from the total cost: (2) - (3). This yields the energy cost for the Core and Shell for both Design and Baseline Models 5. Calculate the percentage savings per LEED-NC and LEED-CS method, using the energy costs for the Core & Shell, as noted in (4) above. We request USGBC\'s ruling on whether this method of calculating percentage energy savings for Core & Shell projects is acceptable. JUSTIFICATION: We believe that this method meets LEED requirements based on the following reasoning: 1. Consistency with other LEED CS credits: The above methodology is consistent with other LEED-CS credits. LEED-CS is intended for the portion of the building that is controlled by the Core & Shell project team, as opposed to the portion of the building that is controlled by the tenant design team. For example, Material Resource credit calculations are based on the cost for the Core & Shell portion only. No cost is assumed for the tenant fitout areas. 2. Correlation between LEED-NC 2.2 and LEED-CS 2.0: The same percentage savings is required to obtain energy points under both LEED-NC 2.2 and LEED-CS 2.0, yet buildings under LEED-CS 2.0 have less opportunity to reduce the energy cost, since Core & Shell developers do not control tenant fitout. If the percentage savings are calculated using the total energy cost (not just the Core and Shell energy cost), the Core and Shell of a LEED-CS building would have to perform much better than the Core & Shell of a LEED-NC building, to make up for the lack of available energy cost reductions in tenant areas. Examples of energy savings that can be achieved within tenant spaces, and that are not available to the Core & Shell Developer, include but are not limited to the following: 1. Lighting load reduction > Reduce lighting density below that of ASHRAE/IESNA Standard 90.1-2004 (the Standard) > Motion detector sensors in areas where they are not already required by the Standard > Perimeter daylight dimming > Lumen maintenance depreciation system for core spaces > Addressable lighting 2. HVAC controlled by tenants > If the HVAC system is configured for fan-powered VAV boxes, or if the HVAC system employs fan-coils, use electronically-commutated motors > Water-cooled DX equipment more efficient than required by the Standard > DDC controls of terminal units 3. Plug load reductions > EnergyStar computers and appliances > Power management software > Motion detection sensors for computer monitors While in very rare circumstances the Developer may mandate certain (but not all) energy cost features to the tenants, including such requirements in the lease is unfeasible for the great majority of Core & Shell developments. In summary, it is our understanding that LEED CS and LEED CI were created to acknowledge the limits of control over design and construction in these project types when compared to owner-occupied buildings (the typical LEED NC project). Our proposed approach to credit EAc1, we believe, is in keeping with this intent." "The applicant is requesting acceptance of proposed modifications in the calculation methodology used for this credit. The proposed methodology is not, however, acceptable as it significantly modified the approved calculation methodology. The applicant should note that the methodology published in the LEED-CS v2.0 Reference Guide was balloted and approved by the USGBC members and cannot be modified via a CIR. The applicant should also note that for Core and Shell, credit can be taken for any energy efficiency measure required by the owner and enforced through the leasing requirements. Examples of these may include limiting installed lighting power or the type and efficiency of HVAC equipment." "None" "None" "LEED Interpretation" "5118" "2008-04-23" "New Construction, Schools - New Construction, Core and Shell" "EAc1 - Optimize energy performance" "The project has developed a strategy for energy savings using diesel power generators on site and considering fossil fuel rates in lieu of utility demand rates during peak time. EnergyPlus results for the project have confirmed that savings with this particular strategy correspond to 14% of the baseline energy cost. Energy consumption rates are regulated by the local utility. - Peak Time: 107.56 USD/MWh | Off-Peak Time: 67.33 USD/MWh During off-peak time, the energy consumption rate will be considered in both baseline and proposed design calculations. During peak time, the energy consumption rate will be considered only in baseline. In the proposed design, power generators will operate on site during this period and the local utility will not be the supplier; consequently, the energy consumption rate will consider only the fossil fuel to operate the power generators. - Fossil Fuel: 405.50 USD/MWh Demand rates are regulated by the local utility. - Peak Time: 16.93 USD/kW | Off-peak Time: 4.15 USD/kW During off-peak time, the demand rate will be considered in both baseline and proposed design calculations. During peak time, the demand rate will be considered only in baseline. In the proposed design, power generators will operate on site during this period and the local utility will not be the supplier; consequently, the demand is free of charge. Running Energy Plus for a single month, the project has had the following results. - Energy Consumption Peak Time: 65 MWh | Off-Peak Time: 610 MWh - Demand Peak Time: 1,918 kW | Off-Peak Time: 3,196 kW Considering only this month as an example of energy savings (the actual simulation takes into account the whole year), calculations should go as follows. Baseline: 65 MWh x USD 107.56 + 610 MWh x USD 67.33 + 1,918 kW x USD 16.93 + 3,196 kW x USD 4.15 = USD 93,797.84 Proposed: 65 MWh x USD 405.50 + 610 MWh x US$ 67.33 + 1,918 kW x USD 0.00 + 3,196 kW x US$ 4.15 = USD 80,692.20 (14% less cost than that from the baseline) This CIR is to confirm that the approach described above is acceptable for achieving points in EA credit 1, considering power generators on site and reducing billing rates." "The applicant is requesting clarification regarding whether peak shaving of purchased electric demand accomplished through on-site diesel generators may be used to demonstrate energy cost savings for EAc1. These cost savings may only be reflected if the generators are modeled using the methodology defined in the CHP Calculation Methodology for LEED-NC v2.2 EA Credit 1 (https://www.usgbc.org/ShowFile.aspx?DocumentID=1354) and the generation system meets all of the CHP System Qualifications criteria listed in this document. Most diesel generators will not meet the requirements spelled out in the CHP calculation methodology. Applicable Internationally." "None" "None" "X" "LEED Interpretation" "5135" "2008-08-02" "New Construction, Schools - New Construction, Core and Shell" "EAc1 - Optimize energy performance" "Saint Ann Court is a LEED registered 26-story high rise office project being developed by Dallas-based Harwood International. Saint Ann Court is located in the Uptown area of Dallas, Texas, adjacent to Dallas\' Central Business District. The Saint Ann Court project team is currently expecting to acquire 38 LEED points on the Core and Shell v2.0 Registered Project Checklist. At the completion of design, the building was in full compliance with LEED Standards and received a building permit prior to June 26, 2007. Due to escalating construction costs and negotiations with the general contractor, the project was not registered with the USGBC after June 26th. The energy modeling for credit EAc1 Optimized Energy Performance was completed last week and the building is currently only 8% more efficient than the baseline design. The first thought was to change the glass since 65% of the building is glass. This solution may no longer be an option, as the Owner has also made move-in date commitments to tenants that do not allow time for losing our production slot at the glass manufacturer should a change in glass be necessary. The mechanical/electrical design engineer is in the process or reviewing efficiency of the HVAC systems to see if additional reduction in energy consumption is possible. This high profile urban project attempting a Gold level certification is in jeopardy of not achieving any certification level with the additional energy performance requirements becoming effective after design and permitting of the project was completed. We believe we can reach the 10.5% in Eac1 with additional insulation installed behind the glass and precast concrete spandrel panels and modifications to the HVAC equipment. We are, however, respectfully requested a variance for this project to continue attempting Gold level certification under the pre June 26, 2007 date allowing 1 credit minimum to be met under Eac1. Harwood International has always constructed developments under strict guidelines to create high performance green buildings. Harwood has made LEED certification a standard requirement in the Harwood Master PD as well as other PD\'s within its Uptown holdings. At completion, the Harwood master planned development will encompasses 8 million square feet of city approved, LEED Certified square footage in 20 development projects. Among the five operating buildings located in Uptown Dallas that Harwood has developed, many have received awards. The Rolex building recently won the Dallas Toby ""Office Building of the Year"" Award, and the Centex building received the EPA Energy Star award as well as it being rated the most energy efficient office building in the U.S. Harwood International has never taken tax dollars from the city, and continues to beautify the area by planting their own trees and incorporating 6.5 acres of parks on private property at owner\'s cost." "The project team is requesting a variance from meeting the mandatory achievement of 2 points under EAc1. Per CIR Rulings dated 11/14/2007 and 11/28/2007, and the errata for LEED-CS v2.0 on the USGBC website (http://www.usgbc.org/ShowFile.aspx?DocumentID=3334), there are other efficiency measures that can and should be pursued to meet the minimum target of 14% in energy cost savings. As the opportunity to pursue measures mentioned in the above CIRs and errata exists for this project, the request for variance is denied." "None" "None" "LEED Interpretation" "5139" "2008-08-26" "New Construction, Core and Shell" "EAc1 - Optimize energy performance" "Our project is being considered for re-registration from LEED-CS v2.0 to LEED-NC v2.2. The building is 65,762 GSF with 48,664 SF of total leasable space. 25,997 SF (53%) of the building has been leased, designed, and under construction. However, the remaining 22,667 SF (47%) is unleased shell space. The unleased shell space is outside of the project scope and there is no design currently underway for this to complete work in this area. In order to pursue EA Credit 1 (Optimize Energy Performance), our engineers would like guidance on how to create their energy model based on our building situation of 53%-to-47% leased vs. shell spaces. It is their intention to model the unleased shell space as if the space were ""upfit"" to the same standard as the leased portion of the building. This standard would be described in a tenant improvement guidelines provided to future tenants. Please verify this method is acceptable or provide an alternate method for energy modeling." "The applicant is requesting clarification regarding energy modeling of shell spaces that do not yet include tenant fitouts. This topic has been extensively addressed in the published erratum for LEED-CSv2.0 (http://www.usgbc.org/ShowFile.aspx?DocumentID=3334), as well as previous CIR rulings (CSv2.0 Rulings dated 05/27/2008, 04/25/2008, 04/23/2008, 04/24/2008, 02/11/2008, 11/28/2007, 12/5/2007, 11/14/2007, and 05/30/2007). For LEED-CS, tenant guidelines alone are not sufficient to verify energy efficiency measures incorporated into future leased space. The published erratum indicates that documentation should be provided including lease or sales agreements verifying that 100% of the leased square footage complies with the credit requirement, and a statement signed by the owner / developer verifying that all leases and/or sales agreements will comply with the credit requirements. For future leased spaces, the letter from the owner / developer is only required if efficiency measure improvements beyond ASHRAE 90.1-2004 are reflected in the future leased spaces (e.g. improved lighting power density, improved HVAC efficiency, etc.). Applicable Internationally." "None" "None" "X" "LEED Interpretation" "5158" "2008-10-24" "Core and Shell" "EAc1 - Optimize energy performance" "Our project is a cold dark shell, suburban retail development registered for LEED NC certification in 2008. The project is a group of eight buildings being submitted for a single LEED certification for the project. Only 3% of the project is core and shell space. Other than this small CS percentage, Tenants\' scope of work includes wall insulation, HVAC systems and interior lighting for the leased area in the project. Tenants will install these components related to EA credit 1. Tenants are not yet under agreement and details of their improvements are not yet known. We intend to meet the intent of EAc1 in part by inserting requirements in the lease agreements for energy optimization of the Tenant installed energy systems and wall insulation levels. We will also provide modeled solutions to Tenant\'s to help guide their initial analyses. Would the USGBC TAG please clarify whether the stipulations of Tenant Sales/Lease Agreements, which are permitted to be used in conjunction with compliance for EAc1 under the LEED-CSv2.0 Rating System, Addendum 2 and errata dated 11/2/2007, are to be modeled identically in the Proposed/Design and Baseline energy models for the tenant spaces, or if Tenant requirements are permitted to be modeled only in the Proposed/Design energy model (while holding the tenant spaces to the standard minimum performance criteria of ASHRAE 90.1-2004 for the Baseline energy model)? CIRs subsequent to the errata allowing the use of Tenant Sales/Lease Agreements have given contradictory or unclear indications on this matter: Some CIRs appear to indicate that baseline and proposed assumptions for Tenant scope must be equal: CIR 5/27/08 - All buildings are to be modeled per ASHRAE 90.1-2004, LEED-CSv2.0 EA Credit 1 and Appendix 2. For items out of owner\'s control, the parameters for the proposed and the baseline models must be maintained as identical. CIR 4/23/08 - Tenant installed HVAC systems are assumed to be identical to the baseline system Other CIRs appear to suggest that lease agreement requirements can be incorporated in the proposed building energy model: CIR 11/14/2007 - It is acceptable to use Core & Shell building efficiency improvements and tenant leasing efficiency requirements to achieve the minimum energy efficiency requirements. LEED-CS errata for EAc1 (dated November 2, 2007) allows a project to meet the EAc1 credit requirements by incorporating tenant sales or lease agreements requirements as part of the tenant scope of work and should be reflected in the project energy model. CIR 11/28/07 - It is acceptable to include the future design for tenant lighting per published erratum. Submit typical lease/sales agreements clearly highlighting the lighting requirements, per the modeling for this credit, that need to be met, as well as how these requirements will be enforced. And other CIRs seem to contradict the above suggesting only Owner installed systems are to be modeled: CIR 4/25/08 - Minimum energy performance and energy savings only applies to systems supplied by the owner. ASHRAE 90.1-2004 clearly states that ""spaces shall be assumed to be conditioned space and shall comply with the requirements for conditioned space at the time of construction, regardless of whether mechanical or electrical equipment is included in the building permit application or installed at that time."" CIR 8/27/2007; if the work performed is not within the core and shell scope, it can be excluded from the all relevant prerequisite and credit calculations and should be modeled as energy neutral. Given the limited scope of work in the Core & Shell scope of work in our project, is it acceptable to incorporate energy efficiency minimums in the proposed building energy model based on required performance thresholds stated in the tenant leasing agreement documents? Secondly, should we assume that all aspects of the LEED NC App. Guide for Multiple Buildings and Campus Projects can be applied to this LEED CS project? Specifically for EAc1 the AGMBC states, ""To receive a single rating for a group of buildings, use a weighted average for the group of buildings based on their conditioned square footage, or aggregate the data into one PRM calculation, so that performance is achieved by buildings of varying sizes within a certifying group. Each building must still meet EA Prerequisite 1 and may receive its own rating if that is desired."" If the AGMBC does not apply to our CS project, is it acceptable for our team to analyze energy optimization using a single energy model with appropriate aggregated areas, orientations and loads for all eight of our buildings?" "As per the LEED-CS errata dated 11/2/2007, tenant lease agreements are acceptable to claim credit in the Proposed Case models. The applicant should note these requirements are part of the tenant lease and intended to be strictly enforced by the landlord/ owner. In addition, this Core and Shell project may follow the guidance in the LEED-NC AGMBC for EAc1.\nUpdate April 15, 2011: Please note that all 2009 projects seeking multiple buildings guidance must refer to the 2010 Application Guide for Multiple Buildings and On-Campus Building Projects, located here: https://www.usgbc.org/ShowFile.aspx?DocumentID=7987\n\nUpdate April 15, 2011: Please note that all 2009 projects in multiple building situations must follow the 2010 Application Guide for Multiple Buildings and On-Campus Building Projects, located here: https://www.usgbc.org/ShowFile.aspx?DocumentID=7987. 2009 project teams should check this document for up to date guidance on all multiple building issues. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5206" "2009-05-21" "New Construction, Schools - New Construction, Core and Shell" "EAc1 - Optimize energy performance" "We have a question concerning how to draw the LEED project boundary of the C&S project described below. The goal of our client is to develop a sustainable shopping center and therefore planning has been executed with high standards of green building design. The scope of the project is a shopping center that is being built on a previously developed site in an urban environment. Some areas of the shopping center are built under ground level and one part extends underneath an old office building located on the site. There are also two residential buildings being constructed as a separate project on top of the shopping center. This is an example of building stacking, which increases development density and enhances community connectivity. Question: Can the office and residential buildings left outside the LEED project boundary despite the fact that the buildings are physically attached to the shopping center? Justification: The shopping center, the office building and the residential buildings form their own legal entities. In the country where the project is located the real estate register is 3-dimensional and the buildings are legally seen as separate real estate. Therefore the shopping center developer does not have control over the office building located and the residential buildings being built on top of the shopping center. The bottom floor of the office building is detached from the office building, rebuilt and attached to the new shopping center, but the rest of the office building is not within the scope of the shopping center development project and will be left as it is. The construction of the residential buildings is a totally separate project with a different time schedule and constructor. If the buildings were built side by side there would not be any doubt about project boundaries. Locating the office and residential buildings on top of the shopping center instead of being built side by side increases development density and enhances community connectivity. We see that the shopping center solely forms a LEED project in this case." "Based on your description of this specific project, the office and residential buildings could be excluded from the LEED project boundary, as long as the separate buildings do not commonly share energy systems. For energy modeling purposes, the shopping center would need to consider any potential energy reduction benefits (shading, blocking wind, etc.), from the existing office building or projected residential buildings, in the baseline and proposed case. It is essential that these ""unregulated"" components are consistent between the two models. It is pertinent to note that the exclusion of the office and residential buildings from the analysis is purely related to their location vis-" "None" "None" "X" "LEED Interpretation" "5224" "2009-07-16" "New Construction, Schools - New Construction, Core and Shell" "EAc1 - Optimize energy performance" "The project in question is an existing office building of which everything was demolished with the exception of the structure, slabs and roof. The building\'s skin was reconstructed and the mechanical systems were redesigned. The question is regarding the baseline model calculations used in the Energy and Atmosphere Credit 1 - Optimize Energy Performance. The credit requirements for Whole Building Energy Simulation say to use the Performance Rating Method in Appendix G of ASHRAE/IESNA 90.1-2004 to establish baseline building performance. One of the requirements of this standard (G4.1A - Baseline Building Envelope Orientation) states that ""the baseline building performance shall be generated by simulating the building with it\'s actual orientation and again after rotating the entire building 90, 180, 270 degrees, then averaging the results."" This requirement makes sense when talking about a building in new construction because you have the option to orient the building in such a way as to take maximum advantage of passive solar design, wind currents, etc. With an existing building the existing orientation is already determined so it doesn\'t make sense to establish a baseline off of the average of four orientations. When we model it this way we lose 6% of our energy reduction compared to the design case. We would like to ask if based on the fact that this building\'s orientation was already set because it is a rennovation project, that we can establish the baseline energy model solely off of that building orientation, not the average of all 4." "The applicant is asking if the project can be exempted from the rotation requirement of ASHRAE 90.1 Appendix G. Given the existing nature of the building, it would appear that the existing orientation, as well as the existing envelope would fall under the ASHRAE Appendix G Table 3.1, 5f requirement for Existing Buildings that states: ""For existing building envelopes, the baseline building design shall reflect existing conditions prior to any revisions that are part of the scope of work being evaluated"" Given that the existing building is already situated as stated in the CIR this set existing condition can be modeled as constant in the baseline. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5297" "2008-03-13" "New Construction, Schools - New Construction, Core and Shell" "EAc1 - Optimize energy performance" "Our project is a science and technology lab building on the University of Nevada Las Vegas Campus of approximately 181,000 sf, with a 1200 sf greenhouse for experiments. The greenhouse has four cells which will mimic the exact environmental conditions of the Nevada (nuclear) Test Site as they occur in the open desert. Thus the greenhouse cells will be conditioned to match the exact temperature and humidity conditions at the test site; lighting will also match the conditions at the test site. This is being accomplished with a system separate from the rest of the lab building. Since the greenhouse conditioning and lighting is for the purpose of carrying out experiments, it is similar to a lab hood or other lab process equipment. We will treat the energy use from lighting and conditioning the greenhouse as a process load in the Energy Cost Budget Method model and subtract it for calculating the percent energy savings. Please confirm that this approach is acceptable." "Based on the description above, it appears that the energy use would most likely be considered process related and therefore could be excluded from the Energy Cost Budget (ECB) Method model. ASHRAE 90.1-1999 defines process energy as ""energy consumed in support of manufacturing, industrial, or commercial process other than conditioning spaces and maintaining comfort and amenities for the occupants of a building."" Please note that if any of the energy use in the greenhouse is deemed as necessary for the comfort of occupants (lighting, auxiliary heating, etc.) and is not associated with the lab related experiments, then it would need to be included in the ECB calculations as a regulated energy use. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5299" "2008-04-23" "Core and Shell" "EAc1 - Optimize energy performance" "The project is a 1.5m SF retail/entertainment center. The developer is building the main shopping center over which he has direct control as a core and shell project. Certain anchor stores and a spa located at the extremities of the shopping center (but connected to the main shopping center) are being built by the individual store owners and not by the developer (this includes both the envelope and the interior) . The same is true of stores and businesses that will be located on pads at the perimeter of the parking lot (not connected to the main shopping center). There will also be a hotel connected to the shopping center which is being developed at some later point in time by a separate hotel owner. This CIR is to validate that only the portions that the developer controls and builds is subject to the LEED core and shell requirements and that buildings built by anyone other than the developer are not subject to LEED core and shell requirements." "The CIR is inquiring if separate structures within a multi building project can be excluded from the scope of the LEED-CS submittal. For the purposes of LEED certification, a project team may define the project boundary in any manner that is applicable to the project\'s scope. The boundary must be consistent across all credit submittals and exhibits. If portions of a project are to be built separately from the initial core and shell construction, they can be excluded from the certification submittal package only if the defined project and excluded portion have separate and independent structural and operating systems. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5309" "2008-04-24" "Core and Shell" "EAc1 - Optimize energy performance" "Appeal for Ruling on LEED CS CIR for credit EAc1 dated 2/11/08 CIR: The PERCENT energy cost savings for EAc1 is based solely on Core & Shell components. Reviewer response: The request ""significantly modified the approved calculation methodology."" ""The methodology published in the LEED-CS v2.0 Reference Guide was balloted and approved by the USGBC members and cannot be modified via a CIR."" Appeal: A. The CIR proposes to clarify, not modify, a calculation method. B. The Reference Guide supports the proposed interpretation of the calculation method C. This interpretation is consistent with the other LEED CS credits. A. LEED-CS RATING SYSTEM, APPENDIX 2 IS UNCLEAR ON THE CALCULATION PROCEDURE FOR EAc1. THE RATING SYSTEM INTENT SUGGESTS THE USE OF ONLY CORE & SHELL ENERGY. ITEM 1.1: Projects must use ASHRAE 90.1-2004 Building Performance Rating Method. This requires that all loads, including tenant loads, be modeled. It does not indicate whether tenant energy is included in the percentage calculations. ITEM 1.2: Tenant spaces are defined by energy using components paid for, metered and apportioned, or billed to, the tenant. ITEM 1.3: ""Thus, the scope of a LEED CS project is limited to those aspects of the project over which the developer has direct control."" ITEM 5: The energy cost of the Budget and Design buildings determine the percentage savings. We contend that Items 1.2 and 1.3 should decide whether the annual costs are of the ENTIRE building or of CORE & SHELL. B. LEED-CS REFERENCE GUIDE, APPENDIX ""CORE & SHELL ENERGY MODELING GUIDELINES"" CLEARLY DIFFERENTIATES BETWEEN CORE & SHELL VS. TENANT ENERGY USE. IMPLICATION: UTILIZE CORE & SHELL ENERGY USE FOR THE EAc1 PERCENTAGE CALCULATION. The percent energy cost savings is calculated as follows: a. MODEL THE ENTIRE BUILDING, including Core & Shell areas AND Tenant Fitout areas NOTE: This procedure is not disputed. b. TRACK SEPARATELY the energy use of Core & Shell vs. Tenant Fitout. NOTE: See 2.2.1.1 and 3.2.1.1. ""Model SEPARATE electric meters for the lighting in the core."" See 2.2.2.1 and 3.2.2.1 ""Model SEPARATE meters for tenant plug loads and process loads."" This signals the intent to use ONLY Core & Shell costs for the percentage calculation. c. SIMULATE, THEN CALCULATE the percentage energy cost savings, using Steps 4 and 5. NOTE: Step 5.1 references the ""budget building"" and the ""design building."" It does not say whether these models are just for CORE & SHELL or the ENTIRE building. However, under ""2. Proposed Building Model"" (term used interchangeably with ""Design Building"") the proposed building is listed as ""2.1 Core & Shell Building."" Same for ""2. Baseline Building Model."" When Step 5.1 refers to the ""annual costs of the budget building and design building,"" it is consistent to assume that, per Step 2, ""building"" means ""Core & Shell building."" Finally, Step 5.3 does not indicate whether the calculation is done using only Core & Shell energy cost, as we believe is the intent of the document, or using the energy cost of the entire building. We contend that this was an editorial oversight. C. ONLY THE PROPOSED APPROACH IS CONSISTENT WITH THE OTHER LEED CS CREDITS Tenant fit-out is not included in the calculation of percentages for: EAc6 Green Power WEc3 Water Use Reduction MRc2, Construction Waste Management MRc3, Materials Reuse MRc4 Recycled Content MRc5, Regional Materials MRc6, Certified Wood EQc4.1-4.4, Low-Emitting Materials EAC2 Renewable Energy references the energy use of the entire building. The percentage savings for CS is 1% vs. 2.5% for NC. For EAc1 the percentages of CS and NC are identical, indicating that the CS calculation refers to Core & Shell energy only." "The applicant is requesting clarification in calculating percentage improvement for EAc1. Based upon the justification provided in the appeal and the proposed approach in the original CIR, the calculation methodology as understood by the design team is not acceptable and does not meet the requirements of EAC1 or Appendix G of ASHRAE 90.1-2004 which requires that the proposed building performance and baseline building performance to include all end-use load components. No doubt, LEED-CS addresses energy optimization of the core and shell systems but at the same time also provides an opportunity for the developer/owner to incorporate energy efficiency features to be included in the sales/lease agreement for fit out of tenant spaces to optimize total operational building energy use. This opportunity may or may not be available to all the owners or may not be feasible at all in some developments. Therefore, it is essential to establish a minimum benchmark for energy optimization, keeping in mind that projects in different markets with different project teams are approaching the energy modeling requirements in a similar manner. Hence, the energy cost of the tenant spaces in those projects on which the developer/owner has no control is essentially kept energy neutral. Therefore, the lighting and plug loads including any HVAC system not part of the core and shell scope should be kept similar in both the proposed and baseline building as prescribed by the relevant section of ASHRAE Standard 90.1-2004 and thus the resultant energy use of the tenant spaces must not be subtracted from the calculations when calculating percentage improvement for EAc1. To further clarify, in EAc1 calculations, the proposed building performance and the baseline performance refer to the total annual energy cost of the whole project which includes the core and shell and tenant scope of work. For projects that can demonstrate energy optimization of the tenant spaces through tenant sales/ lease agreement requirements as part of the tenant scope of work can take credit for the energy cost of the tenant spaces. This approach is acceptable based on published erratum for LEED-CS v2.0 on the USGBC website (http://www.usgbc.org/ShowFile.aspx?DocumentID=3334). Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5358" "2009-09-02" "New Construction, Schools - New Construction, Core and Shell" "EAc1 - Optimize energy performance" "Station Lands - Phase 1 - EPCOR Tower: CIR for Energy and Atmosphere: Optimize Energy Performance (Credit 1) This CIR pertains to the appropriate Baseline system choice for a heated parkade, as per ASHRAE 90.1-2004. The building in question is a 29-storey office building with a 4-level underground parkade located in Climate Zone 7 (very cold, with \'5000-7000 annual heating degree days\'). The parkade is 26,500 sq.m. and requires 5,000 kW of heating capacity to heat the outdoor air (to ventilate the parkade) to above freezing point on the coldest day. The parkade will be heated to 4 \'degC\' in winter, and will not be cooled. In ASHRAE 90.1-2004, 189 W/sq.m. of heating output classifies this as a heated space according to Table 3.1 Heated Space Criteria, and the size of 26,500 sq.m. classifies it as requiring a System 7 - VAV w/ Reheat system in the Baseline according to Table G3.1.1A Baseline HVAC System Types. However, the parkade is a single thermal zone (earth on all walls and underneath, and a fully conditioned office space above), which makes a system choice of VAV seem inappropriate. The Proposed Design is a Built-up Single Zone system with natural gas furnace heat, and no cooling. Guidance from ASHRAE Technical personnel has been that ""the Baseline is to provide a simpler system than the Proposed design."" Question: In accordance with the actual thermal zoning of the parkade and the guideline that it is to be, generally, an equally simple or more simple system than the Proposed Design, should the Baseline system be a single zone system? If not, what is a proper system choice for the parkade in the Baseline case?" "Under Section 3, ""Definitions, Abbreviations, and Acronyms of ASHRAE Standard 90.1-2004 the definition of unconditioned space is as follows: an enclosed space within a building that is not a conditioned space or a semi-heated space. Crawlspaces, attics, and parking garages with natural or mechanical ventilation are not considered enclosed spaces."" The parkade equates to a parking garage and is not considered an enclosed space therefore there is no baseline system. Heating for the space should be modeled identically in both the proposed case and the baseline as process energy. An acceptable baseline would be another single zone natural gas furnace with the minimum efficiency prescribed by ASHRAE Standard 90.1-2004. You can claim energy savings for proposed case via Exceptional Calculation Methodology with all the required documentation. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5401" "2009-07-20" "New Construction, Schools - New Construction, Core and Shell" "EAc1 - Optimize energy performance" "Our client is a Real Estate Investment Trust (REIT) that focuses on the development and ownership of grocery anchored retail centers. They own over 450 retail centers nationwide with over 60 million square feet of gross leasable area. They are interested in adopting a company-wide toolkit that provides consistency in their decision making process as it pertains to energy efficiency and overall sustainable/green strategies, including a minimum of LEED-CS2.0 certification. The main objective of this inquiry is related to the development of a methodology for earning EAc1 points, based upon a customized set of prescriptive energy efficiency measures determined through the energy modeling of five prototypes in eight climate regions that are demonstrated to effectively bring about minimum efficiencies to earn at least two EAc1 points. Currently, our client has developed five different prototype buildings that are distinct to each of the five markets/regions that they work in: Northeast, Southeast, Central, Southwest, and Northwest. Below is an outline of the modeling methodology and a description of the documentation that would be provided for certification review. We would like to propose the following prescriptive methodology for each prototype building, in lieu of performing individual energy modeling for each project seeking LEED certification under LEED-CS v2.0 rating system. If the approach is not acceptable, then we would like to receive guidance from the USGBC as to what aspects would need to be modified to obtain approval. Methodology: Develop a customized process and methodology for identifying the most appropriate energy saving strategies for all core & shell prototype projects. The approach is to use ASHRAE 90.1-2004 Appendix G modeling methodologies to investigate various energy efficiency measures for each of the five markets and prototypes and develop and compile a list of prescriptive building related measures that mirrors ASHRAE\'s Advanced Energy Design Guides (AEDG) Recommendation Table, but is customized to this developers specific project prototype approach. The intent is that only freestanding new construction core & shell buildings with individual HVAC systems are eligible. Projects that utilize energy supplied from district or centralized energy sources, e.g. district plant, would not be allowed to use this approach and must follow LEED guidance for projects using district supplied energy. Each market sector will be sub-categorized, as required, to correspond to one of ASHRAE\'s 8 climate zones. All prescriptive measures will be categorized to a prototype, a climate and to an orientation. The orientation will be determined by which way the building\'s main entryway is facing. All of the adopted prescriptive measures will be generated and evaluated using eQuest DOE2 energy modeling software. The software exceeds ASHRAE Appendix G minimum simulation software criteria. For consistency, the building\'s prescriptive measures will be grouped to correspond similarly with ASHRAE\'s AEDG structure. Below is an outline of how the building components with be grouped and categorized:  Envelope: Roof, Walls, Floors, Slabs, Doors, Vertical Glazing, and Skylights  Lighting: Interior and Exterior Lighting  HVAC: HVAC, Economizer, Ventilation, Ducts  Service Hot Water: Service Hot Water Heater LEED Submission: The documentation that would be provided to USGBC for LEED certification review would consist of the following:  A signed LEED Submittal Template declaring an alternative compliance path has been followed.  A copy of a CIR or other documentation from the USGBC approving the alternative compliance path.  A narrative describing the modeling methods and supporting that they conform to ASHRAE 90.1-2004  A comparison summary table demonstrating that the energy measures implemented in the project correspond with the required prescriptive measures.  Any additional documentation necessary to support the claimed energy savings. This customized approach for EAc1 will result in meeting both the intent and the performance requirements of the credit. Can we proceed with this approach and if not, how would we need to modify this approach to be acceptable to the USGBC?" "The project team is requesting that five standard energy models based on a design \'prototype\' from five different regions be acceptable documentation for all prototype projects from that owner/developer currently pursuing LEED certification in lieu of creating energy models for each project in line with the requirements for EA Credit 1. Each individual project will have energy use/cost variations depending on objects other region and system type. Energy use and cost is greatly impacted by: building orientation, elevation, average solar gain, utility rates, local code requirements, and more. A snapshot prototype energy model will not adequately describe the energy requirements of all projects in the same region, and an individual energy model must be submitted for each building pursuing certification. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "10286" "2013-10-01" "New Construction, Core and Shell, Schools - New Construction, Retail - New Construction, Healthcare" "EAp2 - Minimum energy performance" "A centrifugal chiller, manufactured in Brazil, is specified for the project. The chiller is not AHRI certified and there is no laboratory in Brazil that can do this test. Since there is no laboratory in Brazil that can do this test, to comply with section 6.4.1.4 Verification of Equipment Efficiencies of ASHRAE 90.1-2007 Standard, would the equipment fall under option d (if no certification program exists for a covered product, the equipment efficiency ratings shall be supported by data furnished by the manufacturer)? Can this equipment be used in the project?" "A supplier’s claims regarding energy efficiency would not be considered sufficient to document compliance with EA Prerequisite 2 (Minimum Energy Performance) and EA Credit 1 (Optimize Energy Performance) for a centrifugal HVAC unit that has not been tested and certified by a 3rd party in accordance with AHRI Standard 550-590. However, if the project team can provide documentation that the efficiency has been tested by a third party using an equivalent standard for HVAC efficiency, this testing would be sufficient in lieu of the AHRI Standard 550-990 testing. Any differences in test conditions and the resulting adjustments to the efficiency values claimed in the energy model would need to be described in the project submittal documentation. Alternatively, the project team may use the supplier’s claims regarding energy efficiency if the commissioning scope of work includes field testing of the equipment efficiency for the range of full- and part-load design conditions under which the building will operate; any adjustments related to altitude, etc. must be accounted for in the commissioning testing. In this case, the energy modeling documentation must include details about the commissioning functional testing method to confirm the performance of the chiller at full and part load operation. If the LEED submittal is provided as a split design / construction phase submittal, and the commissioning agent determines that the equipment efficiency does not meet or exceed the efficiency values claimed by the supplier, the energy documentation must be resubmitted at the construction phase with the values measured by the commissioning agent." "None" "None" "X" "Brazil" "LEED Interpretation" "10390" "2014-07-01" "New Construction, Core and Shell, Schools - New Construction, Retail - New Construction, Healthcare, Commercial Interiors, Retail - Commercial Interiors" "EAp2 - Minimum energy performance" "There is significant confusion, and seemingly contradictory LEED Interpretations on the required methodology for addressing “purchased” on-site renewable energy, and/or purchased biofuel that is not considered on-site renewable energy within the LEED energy model. For renewable fuels meeting the requirements of Addendum 100001081 (November 1, 2011) or other purchased renewable fuels, how should purchased on-site renewable energy be treated in the LEED energy model? How should purchased bio-fuels (meaning it I not fossil fuel but is used in a similar manner to bio-fuel) be treated in the energy model?" "For any on-site renewable fuel source that is purchased (such as qualifying wood pellets, etc.), or for biofuels not qualifying as on-site renewable fuel sources that are purchased, the actual energy costs associated with the purchased energy must be modeled in EA Prerequisite 2: Minimum Energy Performance and EA Credit 1: Optimize Energy Performance, and the renewable fuel source may not be modeled as ""free"", since it is a purchased energy source.\n\n For non-traditional fuel sources (such as wood pellets) that are unregulated within ASHRAE 90.1, use the actual cost of the fuel, and provide documentation to substantiate the cost for the non-traditional fuel source. The same rates are to be used for the baseline and proposed buildings, with the following exception: If the fuel source is available at a discounted cost because it would otherwise be sent to the landfill or similarly disposed of, the project team may use local rates for the fuel for the baseline case and actual rates for the proposed case, as long as documentation is provided substantiating the difference in rates, and substantiating that the fuel source would otherwise be disposed of.\n\n When these non-traditional fuel sources are used for heating the building, the proposed case heating source must be the same as the baseline case for systems using the non-traditional fuel source, and the project team must use fossil fuel efficiencies for the Baseline systems, or provide evidence justifying that the baseline efficiencies represent standard practice for a similar, newly constructed project with the same fuel source." "100001081" "None" "X" "X"