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" "10218" "2012-07-01" "New Construction, Core and Shell, Schools - New Construction, Healthcare, Data centers - New Construction, Hospitality - New Construction, Retail - Commercial Interiors, Neighborhood Development" "EAp2 - Minimum energy performance" "This LEED Interpretation pertains to the requirement to limit voltage drop for Energy & Atmosphere Prerequisite 2 for Minimum Energy Performance. The current limit is posing a significant hardship to tall buildings relative to satisfying the mandatory requirements of ASHRAE Standard 90.1-2007 (also applicable in 90.1-2010), referenced in the prerequisite.\n\n Specifically, the requirement in Standard 90.1 to limit voltage drop to not greater that 2% for electrical feeders and 3% for branch circuits (section 8.4.1) has proven to be problematic for large projects which often contain feeders of extended length. By comparison, the National Electric Code does not explicitly regulate voltage drop, but suggests model Code language that limits either electrical feeder or branch circuit voltage drop to 3%, with the combined voltage drop of both feeders and branch circuits when added together not to exceed 5%.\n\n This may appear to be a minor difference, However, when applied to long copper electrical feeders which are present in tall buildings, this absolute constraint from Standard 90.1 on the feeder voltage drop (of 2%) results in a significant increase in the required quantity of copper conductors and associated conduit.\n\n As an example of a higher density regions attempting to resolve this issue, the New York City Electrical Code has adopted the National Electric Code model language as mandatory for all buildings and also included an exception for residential occupancies within buildings to limit electrical feeder voltage drop to 4%, and the combined voltage drop of both feeders and branch circuits to not more than 5%. \n\n This change is in recognition of the inherently short branch circuit lengths in typical NYC apartments, and is based on measured testing results which indicate that voltage drop is often negligible due to the conservative feeder and circuit sizing requirements mandated by other aspects of the Code. Thus, for residential buildings the allowable voltage drop of 4% is twice the allowable voltage drop of 2% as required in 90.1. Depending upon the length and capacity of a particular feeder, this difference can equate to a 3X variance in the required quantity of copper conductors and conduit, with a significant associated cost premium.\n\n The magnitude of the cost premium to satisfy the 90.1 criteria in tall buildings, as compared with New York City Code requirements, can be equal to the total of all of the other cost premiums (hard and soft) associated with achieving LEED certification (at the Silver or Gold level) for a medium to large project in New York City. \n\n In order to resolve this issue, we are proposing an alternate compliance path that we believe would meet the intent of the prerequisite, while at the same time preventing cost prohibitive use of significant amounts of additional copper.\n\n Voltage drop is literally the loss of electrical energy (converted to heat) within a building, therefore regulating voltage drop is no different than regulating the energy efficiency of any electricity consuming device in a building (such as light fixtures or HVAC motors).\n\n Several approaches could be implemented within the LEED rating system to address this disproportionate prescriptive requirement of Standard 90.1. A simple and straight forward approach would be to allow buildings utilizing Appendix G energy modeling as the LEED energy compliance path to include voltage drop as a regulated parameter within both the Energy Cost Budget and Design Energy Cost models. Under this approach, the 90.1 criteria (2% for feeders and 3% for branch circuits) would included in the Energy Cost Budget model, but the Design Energy Cost model would be allowed to include the actual voltage drop that will be implemented in the project design.\n\n This approach would achieve the direct intent of the voltage drop requirement of Standard 90.1 in regulating the energy efficiency of power distribution systems, but through the inherent trade-off methodology of Appendix G would allow projects the flexibility to eliminate a disproportionate cost premium that is otherwise incurred by a prescriptive requirement. " "The proposed alternative compliance path for meeting the mandatory requirement of ASHRAE 90.1-2007/2010 Section 8.4, Voltage Drop Limitation, allowing voltage drop as a regulated parameter within the energy models, is not acceptable; however, a simplified alternative compliance path can be approved. As noted in the Formal Inquiry, code requirements and guidelines allow flexibility in meeting voltage drop guidance in feeders and branches as long as the overall voltage drop from service entrance to the worst-case connection is within limits. For the purposes of this prerequisite, the mandatory provision of ASHRAE 90.1-2007/2010 Section 8.4 will be met as long as the total voltage drop does not exceed 5%. Internationally applicable." "None" "None" "LEED Interpretation" "1694" "2007-03-15" "New Construction" "EAp2 - Minimum energy performance" "California Title-24 requirements indicate that space conditioning controls must be provided to prevent reheating of air that has been mechanically cooled, recooling of air that has been previously heated, or simultaneous heating and cooling. The code specifically exempts zones that have special pressurization relationships or cross contamination control needs. However, the performance methodology defined in the Alternative Calculation Manual does not indicate how systems serving these zones should be treated in a performance energy model. Our project is a hospital where all zones have special pressurization relationships and cross contamination control needs. We are seeking clarification regarding the modeling protocol for the systems serving these zones. PG&E released a document entitled ""2003 Savings by Design Healthcare Modeling Procedures"" to define a methodology for modeling the baseline hospital HVAC and lighting systems, for cases where the methodology is not explicitly defined within the Title-24 2001 standards. Savings by Design is a California incentive program for energy efficiency offered by the major California utilities statewide, and modeling methodologies applied by the program are recognized by the California Public Utilities Commission as being consistent with Title-24 energy efficiency requirements. The ""2003 Savings by Design Healthcare Modeling Procedures"" state: If the standard design practice for the type of system being modeled is a constant air volume system, then the baseline will be a CAV system."" Can we apply this HVAC modeling protocol defined in these 2003 Savings by Design Healthcare modeling procedures to our project? Also, can we apply the lighting requirements defined in the Savings by Design Healthcare Modeling procedures in spaces that are excluded from the Title-24 lighting power density requirements?" "Per an NCv2.1 EAc1.1 CIR Ruling dated 10/21/2004, the Savings by Design approach is not acceptable under this prerequisite because there is insufficient information on the standard assumptions for exempt occupancies. Acceptable options include Title 24, the LEED Energy Modeling Protocol based on ASHRAE 90.1-1999, or choose to demonstrate energy cost savings using LEED NC-2.2 following ASHRAE 90.1-2004, Appendix G." "None" "None" "LEED Interpretation" "1815" "2007-06-13" "New Construction, Commercial Interiors, Core and Shell, Schools - New Construction" "EAp2 - Minimum energy performance" "We are in the process of submitting a Laboratory for LEED certification. The building contains a two-story, 6650 square foot Electromagnetic Compatibility (EMC) Laboratory which houses several shielded enclosures. Experiments are performed in and around the shielded enclosures that are very sensitive to electromagnetic interference (EMF). To minimize EMF issues, a two-tiered lighting scheme was developed. Tier 1 consists of thirty-one (31) industrial high bay luminaires, containing 1000 watt incandescent lamps, which are to be operated when experiments are running because they are EMF neutral. Tier 2 consists of thirty (30) industrial high bay luminaires containing 400 watt metal halide lamps (455 watts with ballast) which are to be operated for maintenance and general illumination when experiments are not running for higher efficiency. The space also contains 1200 watts of accent lighting. The lighting power density (LPD) of Tier 1 is 4.7 watts per square foot. The LPD of Tier 2 is 2.1 watts per square foot. Even if we take into account the Exception to 9.2.4 in ASHRAE 90.1-1999: ""if two or more independently operated lighting systems in a space are capable of being controlled to prevent simultaneous user operation, the installed interior power shall be based solely on the lighting system with the highest wattage"", the 4.7 watts per square foot in this space still far exceeds the 1.8 watts per square foot prescribed in the space-by-space method for laboratories. Because of the highly specialized nature of the EMC Laboratory and the fact that incandescent lamps sources had to be deployed, we feel that the LPD requirements stipulated in ASHRAE 90.1-1999 cannot be achieved. Therefore, we are asking to exclude the EMC Laboratory from our lighting power allowance calculations." "The applicant is seeking a waiver to exclude the EMC Laboratory from their lighting power allowance calculations. Based on the narrative, it would be appropriate to consider the lighting systems that are required only during the experiments as a process load. The lighting that is used for maintenance and general illumination and when experiments are not running needs to be accounted for. However, even this LPD is higher than stipulated. Please note that if the project is targeting EAc1, the applicant must include the larger lighting power density on the appropriate schedule to generate accurate equipment sizing scenarios." "None" "None" "LEED Interpretation" "2241" "2008-08-27" "New Construction, Core and Shell, Schools - New Construction" "EAp2 - Minimum energy performance" "The Natural Sciences Complex is a new three story 51,884 square foot, L-shaped building. The building includes college level science laboratories, laboratory support rooms, faculty offices, classrooms, and study areas. The HVAC system serving the laboratory wing of the building includes a single packaged VAV air handler with hot water reheat coils, a run-around heat recovery loop and a variable volume general exhaust system. In addition, laboratory spaces requiring fume hood exhaust are equipped with variable volume exhaust air devices mounted directly on top of fume hoods. The office wing is naturally ventilated and it is heated by a hydronic heating system. There are five classrooms that have mixed mode ventilation system and they are heated and cooled through the radiant slab. There are sixteen chemical fume hoods, and twelve chemical flow benches located in ten laboratories. Laboratory support rooms contain several storage cabinets that require continuous ventilation. Total fume hood exhaust rate is 11,600 cfm, and total exhaust rate of chemical flow benches is 2,100 cfm. Designed minimum ventilation rate for spaces containing chemicals is four ACH, as recommended by NFPA Standard 45. The same standard prohibits recirculation of chemicals originating from the laboratories. Since the 24,150 square feet laboratory wing contains only a few small spaces without chemicals (total floor area 450 square feet), the packaged air handler serving this area is 100% outside air system. This efficiently utilizes heat recovery system, reduces fan energy, and eliminates need for return air duct. The laboratory spaces are load driven. Total supply and exhaust flow rates for laboratory wing are 38,000 cfm and 33,000 cfm respectively. Following the requirements of the ASHRAE Standard 90.1-2004, Appendix G, Section G 3.1.1, based on usage, number of floors, conditioned floor area and heating source, our baseline model is a constant volume packaged single zone air conditioner with DX cooling coils and fossil fuel furnace. This type of system is assigned to each thermal zone. There is no thermal zone in the baseline model that has supply air capacity of 5,000 cfm or greater, and exhaust air energy recovery was not modeled in the baseline building according to Section G This produced considerable energy savings due to the huge amount of outside air and the requirements for continuous ventilation of the laboratory spaces even during unoccupied hours. Since a large portion of our energy savings is the result of adding heat recovery to our system, we wanted to verify that we have correctly interpreted that the ASHRAE Standard does not require heat recovery in the baseline model for our building. Please advise if this modeling strategy is acceptable by USGBC." "The applicant requests confirmation that their modeling approach that excludes exhaust heat recovery from the baseline case due to baseline case system size is an acceptable modeling approach. This modeling approach is acceptable. The language of Section G3.1.2.10 with regards to system design airflow and outside air percentage refers to baseline case systems, not to proposed systems. As indicated above, the baseline case systems for the laboratory spaces all have air flow less than 5,000 cfm. Therefore, based on the description above, energy recovery would likely not be required in the baseline case systems serving the laboratory spaces. Please note that thermal blocks must have airflow less than 5,000 cfm for any thermal block where energy recovery is modeled for credit, and the size of the thermal block may not be manipulated to reflect a smaller thermal block than would typically be modeled just to avoid the prescriptive requirement for energy recovery." "None" "None" "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.)" "**Updated 7/1/2015 with applicability to corresponding EAp2 prerequisites. \n\n 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" "None" "X" "LEED Interpretation" "5534" "2003-01-21" "New Construction" "EAp2 - Minimum energy performance" "EApr2 requires the Engineer to provide documentation indicating that the local codes are more stringent than Ashrea 90.1. In my case the lighting systems have been designed in strict complinace with California Title 24 energy efficiency requirments. In discussions with many local individuals, we are certain that title 24 is more stringent than Ashrea 90.1. However, no specific source can be located, that can confirm this assumption. I would think, that the USGBC has reviewed this problem before. Is there any documentation regarding this issu?" "For projects IN CALIFORNIA, studies have indicated that Title 24 (2001) is more stringent than ASHRAE 90.1-1999. The USGBC has determined that projects in California may use Title 24 compliance documentation to achieve both Energy and Atmosphere prerequisite 2 and to demonstrate achievement of energy optimization points under EA credit 1. A v2.0 EAc1CIR dated 10/25/01 identifies the credit eqivalence table for achieving energy points using Title 24 (subtract 10 from each ASHRAE performance % number). If Title 24 is the local energy code for this project, it may be used to demonstrate compliance with this prerequisite and achievement of EA c1 points." "None" "None" "LEED Interpretation" "5608" "2003-12-22" "New Construction" "EAp2 - Minimum energy performance" "In our campus project, one of the three LEED registered buildings is unconditioned. The ASHRAE Standard 90.1 indicates that there are no requirements for unconditioned spaces, making the Energy Cost Budget Method not applicable. Are unconditioned spaces exempt from the Minimum Energy Performance EA Prerequisite 2 and the Optimize Energy Performance Credit calculations? If not what methodology is used?" "If the unconditioned building meets the ASHRAE 90.1-99 definition of unconditioned space (i.e. is not a parking garage and has been approved by the building department), then the building meets the LEED EA Prerequisite 2. The unconditioned building cannot qualify for any points under the Optimize Energy Performance Credit because there are no possible energy savings. If this building is a parking garage, then it must treated according to the ASHRAE 90.1-99 requirements for parking garages. Applicable internationally." "None" "None" "X" "LEED Interpretation" "5886" "2002-07-19" "New Construction" "EAp2 - Minimum energy performance" "The peak Air Conditioning Load of Green Business Centre Building is as follows: S.No. Description A/C Tonnage 1 Permanent Technology Centre 26.6 2 Seminar Hall 21.8 3 2 Nos. Meeting Rooms 6.3 4 Offices 9.8 TOTALDiversity @ 95 % 64.5 60 TR On the basis of above calculated load, 60 TR chilling machine has been selected which meets the ASHRAE guidelines of COP criteria as well as use of non-CFC refrigerant. However, at the review meeting with the Client, it has been felt that the building is expected to have varied hours of operation and all areas shall not be occupied simultaneously. Therefore use of the 60 TR Machine will result in waste of energy and compromise on part load efficiency. In view of above, it is opinion of the Owners, Architects and Consultants that 3 Nos. 25 TR Chiller shall be more suitable for the project. However, after carrying out a thorough search for CFC- free chillers of 25 TR capacity, which meets COP criteria of 4.5 as given by ASHRAE, we find that presently no manufacturer is offering such Chiller which meets both the criterias. The best selection of chiller available from M/s. Trane uses R-134a refrigerant (which is non-CFC) and has a COP of approximately 4 (less than 4.45 required by ASHRAE). In view of above, we request you to kindly clarify if our project qualifies for relaxation in the norms and the Credit can be achieved. Further to above, it has been mentioned in the LEED reference guide 2.0 page 126, para 4 that the EMP (energy modeling protocol) makes an exception to computer modeling rule applicable to Buildings with equipment with less than 150 TR of cooling capacity. It states that the base line condensor cooling source can be defined to be air, which encourages use of more efficient water based cooling over air cooling in smaller equipment sizes. In view of the same, equipment specification of equivalent air cooled chillers have been sourced from the equipment manufacturer. It has been found that the best CoP available for equivalent air cooled chiller is 2.53. Subject to agreement on use of 25 TR Chillers with CoP of approximately 4, we would request you to kindly let us know if the Base Building could be modeled with air cooled chiller with CoP of 2.53 ( in place of ASHRAE 90.1 - 2001 specified Norm of CoP 2.8 for air cooled chiller)." "When you are using water-cooled chillers (less than 150 ton capacity) in your project, the exception cited on page 126 of the LEED Reference Guide allows you to use air-cooled chillers as the baseline for the energy performance model. Because of this exception, the proposed water cooled chiller with a COP of 4.0 will exceed the LEED minimum efficiency requirements for the baseline air cooled chillers (approx. 2.8 COP in this case), even though it does not specifically meet the ASHRAE 90.1 guidelines. In modeling the air-cooled baseline chiller, use the ASHRAE minimum efficiency COP of 2.8, not the efficiency of the best equipment you found (2.53). There is no basis for modifying the modeling baseline efficiency because of local equipment availability. Applicable internationally." "None" "None" "X" "LEED Interpretation" "5892" "2002-10-07" "New Construction" "EAp2 - Minimum energy performance" "The project consists of an 8 storey multifamily residential building connected to a large conservatory. The residential building is an adult oriented building, including seniors, and will provide a range of services to the residents, including assisted living. The building is designed so the residents can ""age in place"". As part of the ""age in place"" plan, the quality of life for the residents became a large issue. The owner\'s research indicated that plant gardens were effective in improving quality of life, as they provide a gathering place, the plants trigger positive memories, and the residents will spend more time in a natural, daylit setting. The conservatory space will house a wide variety of plants. The project horticulturist has established temperature and daylight levels required to maintain plants. The temperature levels prescribed by the horticulturist result in heating and air conditioning systems being required. Based on ASHRAE 90.1/1999, it is our intent to exclude the heating and air conditioning systems for the conservatory space only, from the energy simulations, as these systems are providing process energy(as defined on page 10 of the standard) for plant growth. Is this acceptable? " "The definition of \'process load\' on page 10 of the ASHRAE Standard 90.1-99 is ""energy consumed in support of a manufacturing, industrial or commercial process other than conditioning spaces and maintaining comfort and AMENITIES for the occupants of a building."" The conservatory qualifies as an amenity, being provided for use by the residents of the project. Maintaining the plants is not a manufacturing, industrial or commercial process. There is no reason to exclude the conservatory\'s HVAC system from energy efficiency concerns. Therefore, conditioning of the conservatory space must be included in the energy simulation and savings calculations. There are many strategies available to reduce the adverse impact of a conservatory on building energy use. If the project were able to demonstrate that significant efforts were made to reduce energy impacts while providing a demonstrable amenity to indoor environmental quality, a case might be made for an innovation credit." "None" "None" "LEED Interpretation" "5912" "2003-12-15" "New Construction" "EAp2 - Minimum energy performance" "The Seymour- Capilano Water Filtration Plant has a 30,000 ft Operations and Maintenance Centre. The Operations and Maintenance Centre is connected to the main filtration plant process areas (approximately 160,000 ft¦), which are not considered part of the LEED registration. The filtration plant process areas contain equipment, such as pumps, filters, blowers, UV disinfection equipment, etc. The enclosed spaces that contain process equipment have minimal freeze protection heating and condensation control ventilation. Only the Operations and Maintenance Centre is what might be considered ""regularly occupied"" (it contains offices, meeting rooms, labs, control rooms, etc.). We have included the energy required for heating and ventilating all of the areas (both filtration plant process and O&M Centre) in the energy analysis, for compliance with EA Prerequisite 2 and EA Credit 1. This was done for the following reasons: The entire facility is heated and cooled using a central geothermal system, including heat recovery from some of the process loads that is used to heat the total facility. Considering the integrated heating/ cooling system, splitting the energy consumption between the O&M Centre and the filtration plant process would be problematic and arbitrary. ASHRAE 90.1-1999, the energy performance standard referenced by LEED, applies to whole and contiguous facilities. As stated by the Standard, it applies to buildings that are enclosed and ""afford shelter to persons, animals, or property."" The standard applies to the envelope of a building, ""provided that the enclosed spaces are 1. heated by a heating system whose output capacity is greater than or equal to 3.4 Btu/h-sf"" (2.2.(a)). It also applies to ""systems and equipment used in conjunction with buildings"" for HVAC, service water heating, electrical power distribution and metering, motors and lighting. The CIR question is as follows: Since the filtration plant is only minimally heated and ventilated and since the heating and cooling energy for the operations building is derived from a common heating and cooling system that serves the total facilty, is it acceptable to include the energy consumption of the total facility in the energy model. The portion of the building with freeze protection only would likely be subject to the semi-heated space criteria in the envelope tables. Please provide specific energy modeling guidance for addressing the situation as described above, including the contribution of waste heat recovery from process equipment. " "The total energy consumption of the facility should be included in the energy modeling results. This should include the energy for pumps, fans, blowers, filters and UV disinfection equipment (all process loads). The large volume of water in the facility should also be included, as it will have potentially significant impacts on overall energy consumption as well. Process energy should be fully included in the model so that the effect on the HVAC system is taken into account. The energy used directly for the process loads is then subject to post-processing (pumps, filters, UV disinfection, etc) as described in the LEED 2.1 Reference Guide beginning on page 145. The energy used by the HVAC system to account for the process energy is not factored out of the modeling results during the post-processing. The issue of waste energy recovery cannot be fully addressed without additional information. Most process waste energy recovery is not regulated by ASHRAE 90.1 and cannot be included in the proposed energy modeling results (non-regulated energy savings are eligible for an innovation credit). ASHRAE 90.1 regulates certain energy recovery options, such as water-side economizers, exhaust air energy recovery and condenser heat recovery. If you are using the large volume of water in the filtration plant as a heat source/sink for the heat pumps, this would be considered a regulated component and should be model the same for the proposed and budget buildings. Determine the type of energy recovery and whether it is a regulated or non-regulated component under 90.1. Note that the portion of the building with freeze protection only would likely be subject to the semi-heated space criteria in the ASHRAE 90.1 envelope tables. Applicable internationally." "None" "None" "X" "LEED Interpretation" "5915" "2003-03-11" "New Construction" "EAp2 - Minimum energy performance" "The State Legislative Building was originally built in 1927 and has not seen significant modernization since that time. It is listed on The National Register of Historic Places. As such, ASHRAE Standard 90.1-1999, Exceptions to apply. This allows that a historic building ""need not comply with these requirements otherwise applicable to such building or space that is being altered."" This refers to an exception to bringing Envelope, HVAC, Service Water, Power, and Lighting Systems up to the ASHRAE Standard. We propose that in light of Exception to, the existing historic envelope and historic lighting systems become the ""baseline"" for our building simulation model to meet ASHRAE 90.1-1999. Because of their historic nature those building systems will remain basically unimproved. The HVAC system and some lighting in the office areas will be improved, therefore, we will not seek exception for those systems. Do you (USGBC) concur with the approach of setting the baseline of the building using the ASHRAE Exceptions where applicable? " "The historical building exception in ASHRAE 90.1 (Section allows historical buildings to meet this LEED prerequisite without documenting compliance with other specific performance requirements of 90.1. However, this exception only applies to portions of the building which are components of the historic designation, most typically the building envelope. Wholesale replacement of building mechanical or lighting systems must comply with the respective requirements of ASHRAE 90.1. This is particularly true if the project is applying for energy performance credits (EA credit 1). In such a case, the HVAC and lighting baseline performance would be determined by the alteration requirements in ASHRAE 90.1. To determine the baseline then, the project would use the existing designated historic building envelope characteristics, and any upgrade to these conditions would count toward energy performance achievement. Replacements of building HVAC and non-historic lighting fixtures would need to exceed ASHRAE 90.1 requirements for those components to achieve energy performance credits. Applicable internationally." "None" "None" "X" "LEED Interpretation" "5944" "2002-08-16" "New Construction" "EAp2 - Minimum energy performance" "This credit refers to meeting ASHRAE90.1/1999 or local energy code. My question is if the national energy code for Canada will be approved to be used for modeling energy performance & the energy cost budget method." "EA prerequisite 2 requires that the project meet ASHRAE 90.1-99 or the local energy code, whichever is more stringent. The applicant must determine which code is more stringent, meet it, and state which code was used in their credit narrative. If the local code is used, a summary table of the performance requirements should be provided to support the equivalence argument. For the LEED energy savings calculations, there are two options. The first option is to compare the proposed design to the ASHRAE baseline to determine energy savings for LEED points. Modifying the energy model to reflect the default criteria found in the reference standard is the most predictable and simple way to capture these points. The second option is to review the local code and compare it to ASHRAE 90.1-99 and demonstrate the difference in performance. This effort could include a search of published comparisons that appear from time to time in the industry, or it could be based on a rigorous comparison initiated by the applicant. Applicable internationally." "None" "None" "X" "LEED Interpretation" "6009" "2002-12-04" "New Construction" "EAp2 - Minimum energy performance" "We are currently designing the lighting systems for a new laboratory facility for the State of Iowa, Department of General Services. We are concerned about the ability to comply with the lighting power allowances under the 1999 edition of ASHRAE 90.1, which appears to be the more stringent than the 1989 edition. The 1999 edition does not have an overall classification for professional laboratories such as this one. Therefore,to calculate the total lighting power allowance, we must use the space-by-space method, which does provide a sub-category for laboratory rooms under ""office"" building types. To comply, the space-by-space method permits only 1.8 W/sf for the lighting in laboratory rooms. This may work in an office or school application, however, it seems insufficient for professional labs where 100+ footcandles must be maintained (and HID technology is inappropriate). To provide 100 footcandles in the labs on this project, a design approach using energy-efficient fixtures/ballasts with high-performance T8 or T5 lamps requires 2.15 W/sf, which exceeds the 1999 ASHRAE 90.1 power allowance by 0.35W/sf. Unlike the 1999 edition, the 1989 edition of ASHRAE 90.1 takes into account factors such as the ceiling height and methods of lighting control. This facility has high ceilings that are sloped to optimize day-lighting. The 1999 edition eliminated adjustments to the lighting power allowance based on ceiling height and lighting controls. In other words, a large investment is being made for this facility to include day-lighting controls, sloped ceilings to optimize day-lighting, multi-level switching, occupancy sensor controls, and EMS low-voltage sweep controls, but the 1999 edition does not take any of this into account when figuring the overall lighting power allowance. For these reasons, including the ambiguous building classification under the 1999 edition, we request that it be acceptable to base the LEED credit on the 1989 edition of ASHRAE 90.1 (in lieu of the 1999 edition). Thank you " "The benchmark for this prerequisite cannot be changed through the CIR process. However, in the space-by-space calculation method for ASHRAE 90.1-99, the interior lighting power allowance is the sum of lighting power allowances of all spaces. Per ASHRAE 90.1-99 page 51, ""trade-offs among spaces are permitted provided that the total installed interior lighting power does not exceed the interior lighting power allowance."" Therefore extra lighting power density required in one space, such as the laboratory, can be offset by using lower lighting power density in another space. Applicable internationally. " "None" "None" "X" "LEED Interpretation" "6037" "2003-01-13" "New Construction" "EAp2 - Minimum energy performance" "We attempted to submit the following Credit Interpretation Request on Friday, December 20, 2002. This webpage was not working at that time. The CIR was sent to USGBC (Attn: Brendan Owens) via fax on that date as per our discussion with Brendan. If there are any problems with considering this request for the December 20, 2002 (3rd Friday) submission deadline please contact Michael Pratt of Keller Engineers at 814-231-2925. Thank you. CREDIT INTERPRETATION REQUEST #1 - DECEMBER 20, 2002 PREREQUISITE 2 MINIMUM ENERGY PERFORMANCE INTRODUCTION: Prerequisite 2 requires compliance with ASHRAE 90.1. Among other items, ASHRAE 90.1 sets standards regarding meeting mandatory human comfort parameters, including ambient temperature. Juniata College does not wish to install air conditioning equipment in their new Biological Field Station building for reasons outlined below. Juniata College is requesting consideration of provision of an exception from the strict, letter-of-the-law interpretation of Prerequisite 2 regarding compliance with ASHRAE 90.1. BACKGROUND: Juniata is an independent college of liberal arts and sciences, located in the Borough of Huntingdon in central Pennsylvania. The 110-acre main campus is supplemented by a 365-acre Environmental Studies Field Station located approximately 40 miles away on nearby Raystown Lake, providing one of the most distinctive opportunities in environmental science in the nation. The existing field station consists of an old homestead for overnight lodging of students, a maintenance building, a boat launch onto the lake, and a variety of outdoor experiment and research areas. The field station is in a very remote area of the Lake Raystown federal reserve, and is accessed by a nearly five mile long unpaved road through undeveloped forested land. Juniata desires to upgrade this field station by constructing a new Multi-purpose/Dining Hall building with associated infrastructure improvements. This expansion project will allow for the conduction of remote class semesters at the field station for approximately 45 resident students. In addition, Juniata desires to pursue certification for the project under the Leadership in Energy & Environmental Design (LEED) Green Building Rating System. PREREQUISITE 2 MINIMUM ENERGY PERFORMANCE: Intent: Establish the minimum level of energy efficiency for the base building and systems. Requirements: Design the building to comply with ASHRAE/IESNA Standard 90.1-1999 (without amendments) or the local energy code, whichever is more stringent. Submittals: Provide a LEED Letter Template, signed by a licensed professional engineer or architect, stating that the building complies with ASHRAE/IESNA 90.1-1999 or local energy codes. THE CREDIT INTERPRETATION REQUEST: The Raystown Field Station project consists of the construction of a new Multi-purpose/Dining Hall building to provide a remote classroom for conduction of biological fieldwork. The Multi-purpose/Dining Hall building project is underway, and consists of a new 6,000 SF two floor building that will provide a communal gathering place for meals (normally 40 to 50 residents), classroom space, and a meeting location for special events. The building heating system is comprised of a propane fired high efficiency boiler, with in-floor and baseboard radiators. The building ventilation system is comprised of air handling units sized for 100% outside air for the main dining and classroom areas, and fan coil units with required outdoor air CFM for other rooms. During the design charette process Juniata voiced a consistent opinion that the new field station must be in keeping with the existing remote and primitive setting, and with the College\'s mission, being the on-site conduction of biological fieldwork. Consequently many typical conveniences and amenities commonly associated with new educational construction were eschewed in favor of a more rusticated approach. The facility will be largely run and maintained by the student body, and therefore while minimal necessities were provided for, they were kept basic and were often associated with learning experience potential. For example, waterless toilets were elected for installation in the Multi-purpose/Dining Hall Building to provide students a learning experience relative to waste load management. Students will assist with maintenance of the future on-site wastewater and water treatment systems. In keeping with this approach, Juniata also does not wish to install air-conditioning equipment in the new Multi-purpose/Dining Hall building, instead favoring an outdoors-oriented facility via open screened windows and doors. Juniata\'s main campus is only 40 miles away, and they understand full well the weather conditions that can be encountered during central Pennsylvania summers, but they wish to make adjustments for temperature in other ways than via mechanical equipment consuming electrical energy during summer-time months. The proposed building will receive shade from existing tree cover, which was aggressively protected during the design and construction process. Students will have the ability to adjust to weather conditions via dress, which will be geared toward outdoor fieldwork, as opposed to a conventional educational or office atmosphere. Country-cooling will be provided by the nearby lake, and in extreme conditions, window fans may be used. LEED Prerequisite 2 simply states that the project must be designed to comply with ASHRAE/IESNA Standard 90.1. This standard provides minimum energy efficiency requirements for the design and construction of new buildings. The standard does not apply to single-family homes, multi-family homes three stories or fewer, and manufactured homes. Our literal interpretation of ASHRAE 90.1 is that this standard therefore mandates the installation of air conditioning equipment to maintain building temperature within a certain comfort parameter temperature range for a certain duration for our proposed application. Under this literal interpretation there apparently is no concession relative to a desire not to use air conditioning equipment relative to the proposed Multi-purpose/Dining Hall structure. While we have spent some time performing energy modeling for the proposed building, we quickly concluded that we couldn\'t meet the letter of the law as defined by ASHRAE 90.1 absent air conditioning equipment. It is our opinion that ASHRAE 90.1 is geared to conventional new construction applications, such as office buildings, schools, and hospitals in developed areas and settings. These applications most often result in conventional approach closed building systems, with human comfort parameters maintained by year-round energy consumption in the form of mechanical heating and air conditioning equipment. We would maintain that our project is at the opposite end of this scale relative to its rural setting, the type of proposed occupants, and the rustic nature of its intended use, and is much more akin to a summer camp development than to a standard school or office building. Will the Counsel provide an exception from the strict and literal interpretation of ASHRAE 90.1 pertaining to mandatory installation of air conditioning systems relative to Juniata College\'s proposed application, enabling Prerequisite 2 to be met? " "Compliance with ASHRAE 90.1 does not require the project to install air conditioning, and the project can certainly meet EA prerequisite 2, and conceivably achieve some energy efficiency credits without installing air conditioning. The ASHRAE 90.1 energy modeling protocol requires that projects assume that air conditioning is present in the baseline and proposed buildings for the purposes of modeling energy performance. In other words, under the ASHRAE protocol used by LEED, your project cannot take credit for saving energy over an air conditioning system that was never intended to be installed. To achieve energy performance credits, the project must either assume (for the purposes of energy modeling only) that both the baseline and the proposed project have an identical air conditioning system, or follow the modeling protocol for naturally ventilated buildings to determine appropriate energy savings." "None" "None" "LEED Interpretation" "6237" "2001-05-01" "New Construction" "EAp2 - Minimum energy performance" "4. Prerequisite 2: Minimum Energy Performance. The Requirement includes the following statement: ""Analyze expected seline building performance using the System/Component Method."" The Reference Guide (I have a copy of the Review Draft) includes the following: ""Provide a summary table of design features that minimally comply with applicable mandatory and prescriptive requirements in ASHRAE/IESNA 90.1-1999, Sections 5-10 or local energy codes (whichever is stricter) OR a copy of the Energy Cost Budget Compliance Report."". This sentence would imply that we can show compliance with the Minimum Energy Performance using the Energy Cost Budget method instead of the System/Component method. This would reduce the amount of work required. Can we provide a copy of the Energy Cost Budget Compliance Report to meet Prerequisite 2?" "A copy of the Energy Cost Budget Compliance Report can be submitted to meet this prerequisite. The report must show compliance to the reference standard. 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 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." "Update Applicability of LI 10286" "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"