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" "1083" "2005-05-13" "New Construction, Commercial Interiors, Core and Shell, Existing Buildings" "The project, part of a HOPE VI development, is a six-story building containing 119 units of affordable housing. It employs non-combustible construction, interior partitions use metal stud framing. The project development team decided early in the process to render high performance and green in an affordable housing project even though this goal had not been proven in the local market. As compliance with the ETS control provisions is prerequisite, nothing short of the totality of this project\'s efforts toward LEED1/2 certification as well as all contingent funding is in the balance. The 12/3/2003 Credit Ruling describes an alternate compliance option that may be used in residential buildings. The performance target of 1.25 sq. in. equivalent leakage area per 100 sf. (ELA/100) of total enclosure area is beyond practicality for this project and may generally be so for other buildings of this type. Complex building systems coupled with accepted building practices inhibit continuous internal air(or smoke) separation between spaces. These difficulties multiply in steel construction where structural members and metal stud walls act like ducts connecting spaces within a building. Corrugated metal decks create conduit fields that impose monumental challenges to compartmentalizing by readily available products and skills. Abundant resources might be able to approach the nominal target, but such efforts may distract from more effective means to achieve the intent of the prerequisite. While a robust level of compartmentalization is essential for control of indoor air contaminants, control of pressure differences is also crucial. Each dwelling unit in this building has continuous mechanical exhaust of ~50 cfm and no other mechanical exhaust. Each apartment is also equipped with a dedicated outdoor air intake to help assure that make-up air is drawn directly from the exterior. With the residential ventilation system being direct, in-unit, and constant duty, the common area ventilation system is able to be more nearly balanced thus minimizing mechanically-induced pressure differences between corridors and other spaces as well as between floors. The building has a fluid-applied air barrier at exterior walls and a membrane roof that help to reduce the impact of exterior pressures acting on the building. The alternative compliance option references ASTM E779. We pose that ASTM E1827 is more relevant to the compliance option. It expressly provides guidance to the use of blower-door equipment, which has significant advantages in application to the ETS standard: - More widely available in region and significantly less costly than larger purpose-built pressure testing apparatus. - Multiple blower-doors are capable of inducing sufficient pressure to overcome background variability. It is unlikely that a building\'s mech. system would be able to induce such pressure unless it is enormously oversized. - Multiple blower-doors able to induce more even depressurization of whole buildings than a single fan. ASTM E779 indicates that ""uniform pressure be maintained within the conditioned space to within +/-10% of the measured inside/outside pressure difference."" There are also important differences between the standards\' measurement procedures. E779 requires multiple measurements across a range of pressures starting as low as 10 Pa. Measurements toward the lower end of the pressure range are subject to greater background variability and, therefore, have a de stabilizing effect on conclusions. E1827 provides a ""Single-Point Method"" that requires multiple measurements near 50 Pa. Project Proposes: Performance Target: 3.0 ELA/100. In combination with the ventilation strategy and exterior air barrier strategies, this performance target represents huge progress toward effective control of indoor air contaminants. It also requires substantial effort beyond standard industry practice. Methodology: ""Single-Point"" methodology described in ASTM E1827." "This revised ruling (posted 11/2/05) is intended to restate and clarify the CIR ruling of 5/13/2005. 1 - the requestor\'s proposal to use ASTM E1827 to verify apartment leakage rates instead of ASTM E779 is unacceptable. Although the two test protocols serve similar purposes, E1827 requires fewer data points (either one or two) over a narrower pressure range (12 to 50 Pa) compared to E779 (five points, at different pressures from 10 to 60 Pa). Compared to E779, E1827 provides a less complete and less robust leakage curve, and thus a less accurate leakage rate value. 2 - the request that the leakage rate requirement be weakened from 1.25 square inches of leakage area per 100 square feet of enclosure area to 3.00 ELA/100 is denied. The value of 1.25 ELA/100 appearing in the 12/03/2003 ruling is the Technical Advisory Group\'s judgment of a reasonably achievable goal. This goal was derived from knowledge of existing industry practice for good, airtight construction in apartment units. Structural design traits have little if any impact on achievability of the goal; the main drivers are the sealing properties of the doors, windows, and wall finishing (drywall, penetrations, etc.). The requestor\'s proposed alternative of simply providing 50 CFM of continuous mechanical ventilation does not guarantee that this prerequisite\'s intent will be met. Moreover, the passive-oriented ""prevention"" approach of having a tighter leakage rate is more robust to fluctuating real-time conditions than increased mechanical ventilation. As further points of clarification, note that a) the leakage requirement applies to each member of a sample of individual apartment units, not the building as a whole, and b) the whole-apartment unit leakage test must be performed regardless of whether the project uses weatherstripping on the doors to the hallway. Use of weatherstripping only eliminates the need for hallway pressure tests. --------------------- ORIGINAL RULING: The project is proposing a higher allowable equivalent leakage area (ELA) performance standard (3.0 ELA/100 vs. 1.25 ELA/100) on the basis that each residential unit is at roughly the same pressure as adjacent units, which will result in low leakage rates. Based on the information provided, it is not possible to conclude whether the proposed approach will satisfy the prerequisite requirements. First, it is not apparent how the value of 3.0 ELA/100 was calculated. Is this a direct result of applying the ASTM E1827 methodology instead of ASTM E779? Is it correlated to the 50 cfm of exhaust air per unit? It is not clear whether the corridors are positively pressured compared to the apartments. A CIR Ruling on 10/5/2004 provides guidance that corridors should be positively pressurized if weather-stripping is not present on the doors. You will need to meet either the weather-stripping or corridor pressurization requirement to satisfy this prerequisite. Make sure to assess your outdoor air intake design for compliance with ASHRAE 62 (the referenced standard in EQ prerequisite 1). The approach of providing a dedicated outside air intake and high volume exhaust fan in each unit will qualify as an alternate compliance path if these two issues can be resolved." "549, 680, 774, 922" "None" "LEED Interpretation" "1492" "2006-04-14" "New Construction, Commercial Interiors, Core and Shell, Existing Buildings, Retail - New Construction, Retail - Commercial Interiors, Healthcare" "How are balconies to be addressed within the multi-unit residential compliance path presented by the 12/3/03 NCv2.1 CIR and NCv2.2 Option 3? And how are balconies treated within the option for prohibiting smoking? The credit requirements are not clear in this regard." "Any potential smoking outdoors must be addressed in regards to secondhand smoke exposure. Balconies are automatically considered smoking areas unless smoking on them is prohibited (by the building manager in the case of a leased apartment; by the initial HOA Rules and Regulations in the case of a condominium). For any compliance path, if a balcony does not comply with the requirements for exterior smoking areas (at least 25 feet away from entries, operable windows and outdoor air intakes), smoking must be prohibited on the balcony. LEED projects registered before September 4, 2006, will not be held to this interpretation, but are encouraged to do so. This ruling reflects the original intent of the IEQ Technical Advisory Group and is considered consistent with the non-residential compliance paths and with the mission of green building. The ruling is also considered reasonable because eighty percent of the U.S. population does not smoke." "1957" "None" "LEED Interpretation" "495" "2003-03-18" "New Construction" "A previous USGBC Ruling for a multi-family building accepted tracer gas testing of a 10% sampling of unit-to-common area interfaces as an adapted Prerequisite requirement, wherein common areas are non-smoking and dwelling units, in which smoking cannot be controlled, are the ""smoking rooms"". Most commercial and institutional buildings avoid the issue and cost of tracer gas testing by being smoke-free as a matter of policy. As the previous Ruling recognized, multi-family buildings present a different usage scenario. Testing even a 10% sampling of the units according to the ASHRAE-129 standard can add a significant cost to a project budget for a procedure that is normally not done for this building type. Yet since it is part of a LEED Prerequisite, the cost is unavoidable for any project of this building type seeking LEED Certification. Firstly, can less than a 10% sampling be accepted for the Prerequisite requirements? Secondly, we propose the following method for meeting the intent of this prerequisite with an alternate testing protocol that we believe fulfills the mission of ASHRAE-129 without all of its added complexity and associated cost: 1) Collect outdoor measurements for temperature, relative humidity, carbon monoxide and carbon dioxide. 2) Monitor for carbon dioxide and other parameters to establish a baseline for selected apartment units. 3) Release carbon dioxide into the selected unit, one unit at a time, until it reaches a sufficient equilibrium. 4) Monitor for carbon dioxide in adjacent units and areas. 5) Repeat on remaining units or 10% of the building. 6) Calculate the air change effectiveness. 7) Collect relevant documentation on building systems and history. 8) Provide preliminary debriefing upon completion of calculations. 9) Provide final report inclusive of all data collected, findings, discussion of significance and a tracer gas analysis report. Please comment as to whether the above methodology is acceptable, and state what minimum unit sampling (ie 10% or less) is required to meet this Prerequisite." "The proposed testing methodology is not acceptable, as it would represent a significant change in standard. Please follow the instructions in the CIR dated 1/18/2002, including the 10% sampling rate." "None" "None" "LEED Interpretation" "5461" "2004-02-23" "New Construction" "A CIR ruling on 12/3/2003 established an alternative compliance protocol for the ETS prerequisite in residential buildings. That protocol requires, among other things, ""all doors in the residential units leading to common hallways shall be weather-stripped to minimize air leakage into the hallway."" This requirement contradicts a standard building practice which is consistent with the intent of the prerequisite: using undercuts on doorways from units to corridors, coupled with pressurized corridors, to maintain positive pressure in common areas relative to residential units. This practice is used to prevent kitchen odors from entering common areas, but would also keep ETS from common areas, the intent of the prerequisite. We propose that the weather stripping requirement be waived if (1) all of the other requirements of the residential compliance pathway are performed, and (2) a project can demonstrate through engineering documentation and narrative that the corridor will maintain positive pressure relative to the residential units at all times." "As stated in EQp2 CIR dated 12/3/2003, there are two alternative methods listed for complying with the prerequisite requirements. The approach you describe (eliminating the weather stripping around the door and allowing the corridor\'s positive pressure to provide the units with their make-up air) will not meet the requirements of the prerequisite. Due to wind and stack effect and other variables there are times when the corridors cannot maintain a consistent positive pressure or ensure that ETS would not transfer from underneath the door into the common areas. The logic behind the weather stripping is to minimize air leakage into the corridor regardless of exterior conditions or the operation of bathroom/kitchen exhaust within the units. Even with positive corridor pressure, kitchen smells do migrate to corridors in high rise residences. Please note that providing make-up air from the corridor is not allowed under some codes (e.g, UMC) and can lead to moisture and mold problems in humid climates. To satisfy this prerequisite, the design would need to demonstrate that ETS transference is prevented from entering the corridor or common areas by conforming to the prerequisite performance requirements. This can be accomplished by following the designated smoking room or tracer gas testing provisions or by conforming to one of the alternative compliance options as listed in EQc2 CIR dated 12/3/2003 (which would require weather-stripping). " "None" "None" "LEED Interpretation" "549" "2003-06-04" "New Construction" "We are utilizing LEED for a 5-story, 50 unit multifamily apartment building in downtown Seattle. As with other residential buildings utilizing the commercial rating system, we will meet the intent of Prerequisite 2 by prohibiting smoking in all common areas and by placing all residential units at negative pressure, with the corridors at positive pressure. All of the units are designed and constructed with continuous exhaust ventilation. Both our consulting engineer and our technical consultant from the Energy Management Services division at Seattle City Light have recommended utilizing a manometer to test for the pressure differential and verify negative pressure in the units. A digital manometer would be used to test the pressure differential between the in unit private residential spaces and the common area corridors and common spaces in the building when all systems are fully operational. Two units will be tested per floor [a total of 10 units and a sampling rate of 20%] to establish the negative pressurization and atmospheric isolation of the units from the common spaces. A blower door test of the units will also be done to establish specific areas of potential air leakage and the overall air tightness of the residential units. Would you please verify that the above testing method will allow us to meet the requirements of EQ Prerequisite 2. Previous credit interpretation requests (1/18/2002 & 1/31/2003) have been based on the use of a tracer gas testing to verify negative pressure. Should this method be required in lieu of the manometer testing suggested above, would you please elaborate on your response of 1/18/2002 in which you note that the tracer gas testing study needs to be ""properly designed""? Does this simply mean, as you suggest, testing an appropriate variation of unit locations (as we would do in conducting the manometer testing) or is there a more detailed protocol that must be followed?" "*** THIS RULING HAS BEEN SUPERCEDED BY EQp2 RULING DATED 12/3/2003*** The IEQ Technical Advisory Group (TAG) has reviewed this CIR and ruled that the scope of the answer exceeds the TAG\'s mandate. While the TAG can approve alternative compliance paths to document credit achievement, this CIR would effectively change the standard in a substantive way. The proposed change in standard can only be incorporated within LEED through a USGBC member ballot. As such, this CIR has been directed to the LEED Steering Committee for resolution. The IEQ TAG will provide appropriate technical support to aid the LEED SC in resolution of this CIR. While the LEED SC will expedite the review and decision on this CIR to the greatest possible extent, no resolution timeline can be provided at this time. Applicable Internationally." "680, 774, 922, 1083" "None" "X" "LEED Interpretation" "5788" "2005-10-03" "New Construction" "Please provide clarification regarding EQ prerequisite 2, and the credit interpretation ruling dated 12-3-2003. The condos in one of the buildings on our campus are served by elevators and stairwells that open directly into the residential units. These elevators and stairs are not pressurized, but are required to resist the passage of smoke and fire as prescribed by the building code. The elevator doors have a UL approved brush system to prevent the passage of smoke, and the stair doors are equipped with smoke seals as well. Based on our compliance with the fire and smoke proofing requirements for these doors, it is our position (and the code requirement) that tobacco smoke cannot migrate from one unit to the next. How do you recommend that we document this compliance? Would weather-stripping and air leakage testing in compliance with E779-99 be adequate to document the LEED point? Is pressurization only required when weather-stripping is not provided?" "This revised ruling from December 2005 is intended to restate and clarify the CIR ruling of 5/13/2005. 1 - The requestor\'s proposal to use ASTM E1827 to verify apartment leakage rates instead of ASTM E779 is unacceptable. Although the two test protocols serve similar purposes, E1827 requires fewer data points (either one or two) over a narrower pressure range (12 to 50 Pa) compared to E779 (five points, at different pressures from 10 to 60 Pa). Compared to E779, E1827 provides a less complete and less robust leakage curve, and thus a less accurate leakage rate value. 2 - The request that the leakage rate requirement be weakened from 1.25 square inches of leakage area per 100 square feet of enclosure area to 3.00 ELA/100 is denied. The value of 1.25 ELA/100 appearing in the 12/03/2003 ruling is the Technical Advisory Group\'s judgment of a reasonably achievable goal. This goal was derived from knowledge of existing industry practice for good, airtight construction in apartment units. Structural design traits have little if any impact on achievability of the goal; the main drivers are the sealing properties of the doors, windows, and wall finishing (drywall, penetrations, etc.). The requestor\'s proposed alternative of simply providing 50 CFM of continuous mechanical ventilation does not guarantee that this prerequisite\'s intent will be met. Moreover, the passive-oriented ""prevention"" approach of having a tighter leakage rate is more robust to fluctuating real-time conditions than increased mechanical ventilation. As further points of clarification, note that (a) the leakage requirement applies to each member of a sample of individual apartment units, not the building as a whole, and (b) the whole-apartment unit leakage test must be performed regardless of whether the project uses weatherstripping on the doors to the hallway. Use of weatherstripping only eliminates the need for hallway pressure tests. ------------------ ORIGINAL RULING: Pressurization of elevators, stairs, and corridors in the project is not required for compliance with LEED-NC EQp2. Hallway pressurization is not required when there is no weather-stripping on the hall door. Rather, if the building design is such that the hallway is pressurized to provide air through the undercut of the door, and thus cannot have that undercut weather-stripped, then the undercut of the door need not be weather-stripped. In this case the hallway pressurization must be tested to verify it is adequate as described in Option B. The weather-stripping and other measures described in the CIR to isolate the residential units from the common areas may mitigate smoke migration between the units, but this must be confirmed by testing. In order to demonstrate and document compliance with EQp2, the project needs to follow the testing procedures outlined in the Alternative Compliance Option 2 from the CIR ruling published on 12-03-2003, which references ASTM E779-99. " "None" "None" "LEED Interpretation" "5857" "2002-01-18" "New Construction" "The IEQ Prerequisite 2 of the LEED V2.0 Rating System was designed for commercial buildings, where the banning of smoking (or limiting it to designated areas) is achievable. In a residential apartment building, the owner is much more limited as to what behavioral restrictions can be placed on the residents within their units. Our project is committed to adhering to the intent of this prerequisite by banning smoking in all common areas of the building. Apartments will have negative pressure to prevent the trespass of ETS into the corridors. Tracer gas testing in accordance with the ASHRAE Standard 129-1997 will be performed between the apartments and corridor (at a sampling rate of 10% of the units). We propose that these actions be viewed as sufficient to meet the intent of this credit for a residential setting." "The LEED Steering Committee provided an interpretation of this Inquiry. The Committee believes that this approach could meet the requirements of EQ Prerequisite 2 if the tracer gas testing study is properly designed. The concern was that a variety of factors such as temperature, wind speed and direction, and building height have significant effects on tracer gas test results. Because the applicant wants to test a subset of the residential units, it is important that the study be designed to account for outside influences on tracer gas behavior. By carefully selecting a representative sample of building conditions in the study design, the committee feels that the applicant may be able to demonstrate compliance with the requirements of the prerequisite. Successful results of a well-designed tracer gas testing study will be acceptable to demonstrate compliance with this prerequisite." "None" "None" "LEED Interpretation" "6051" "2004-10-05" "New Construction" "We have been utilizing the LEED rating system for a 4 story, 51 unit multifamily affordable apartment building for recently homeless families and individuals on the southside of the City of Chicago, and we have been watching the CIRs on this Prereq. with great interest. As with other residential buildings utilizing the commercial rating system we will meet the intent of this Prerequisite 2, by prohibiting smoking in all common areas and by placing all residential units at negative pressure. All of the units are designed and are being constructed to have continuous exhaust ventilation. This is a standard building practice for this region. This design approach is, in fact, considered a ""good practice"" as these buildings become well ventilated as compared to the ""stale air"" atmosphere that occurs in buildings where the corridors are not designed to be pressurized. The latter condition is what the USGBC is currently endorsing by insisting on the weatherstripping of the corridor doors in the Alternative Method Option 2 of the 12/03/03 Ruling for residential buildings of this type and design. The stack effect, wind and other concerns cited in the 2/23/04 Ruling on the 2/06/04 CIR (which asked that the weatherstripping requirement be waived in cases similar to ours), should not be generally applied to all multi-family projects and especially not to low-rise ones. As it can be proven and documented that the air is moving in the correct direction and that the system is working properly by balance tests like the manometer test suggested in the 5/15/03 CIR, to which there has not yet been a formal CIR response. (We received the same recommendation from our State Energy Efficiency Program Representative as the Seattle project in the 2/06/04 did, which was to propose that a manometer test be used to document that the building is performing as it should in terms of the differential between the corridors and the units. Please note that our objection to the Alternative Method Option 2 is limited to the weatherstripping requirement at the doors, because it goes against good practice and design.) We request that USGBC seriously consider expanding the Alternative Method Option 2 to include the possibility of providing documentation through sample manometer testing in Low Rise Multi-Family Residential Projects in appropriate climates, in lieu of the weatherstripping requirement. (The weatherstripping requirement can remain as an option for Projects where the Corridors are not pressurized.) " "The IEQ Technical Advisory Group has addressed this credit through an addendum issued through the EQp2 Ruling dated 12/3/03 by allowing Alternative Compliance Options 1 and 2 for multi-unit residential buildings. USGBC (via the IEQ Technical Advisory Group) agrees with your assertion that maintaining a positive pressure in the hallway relative to the residential unit can minimize air leakage from the unit into the hallway as effectively as weather-stripping doors, provided the pressure difference is maintained. Thus, the committee approves the following addendum to the weather-stripping requirement be added at the end of the last bullet item for option 3 in the EQp2 Ruling dated 12/3/03: ""It is not required to weather-strip the doors connected to common hallways if hallways are positively pressurized with respect to residential units, and the following additional testing is conducted. The pressure difference shall be measured and recorded at least once every 10 seconds for at least 15 minutes; the average recorded pressure difference shall be no less than 5 Pa (0.02 inches of water gauge), with the lowest recorded pressure difference no less than 1 Pa (0.004 inches of water). Tests shall be made with all doors closed and with only those fans operating that are designed to operate continuously; occupant switch controlled fans shall not be operated during the tests."" A manometer is standard equipment for such measurements. " "None" "None" "LEED Interpretation" "610" "2003-08-14" "New Construction, Commercial Interiors, Core and Shell, Existing Buildings" "The City of Charlottesville is currently in the process of planning a multi-use transit center for which we are pursuing a Silver LEED accreditation. The multi-use facility in design will include the shell for installation of a restaurant on the upper floor of the building. Locating a restaurant at this site is ideal in marketing terms due to the popularity of the surrounding areas and the high quality of restaurants already in the area. The restaurant space will, of course, be required to comply with all credits pursued by our organization, as described in our application. With a grand total of 23, 295 sq ft of enclosed space in the multi-use facility, 15,795 sq ft of that will be designated non-smoking and the remaining portion, confined to the restaurant\'s enclosed space will be isolated through the use of negative pressure ventilation and an isolated HVAC system that effectively eliminates any contamination of restaurant air with air circulated through the rest of the facility. The fidelity of the isolation measures will be tested in compliance with methods described in ASHRAE Standard 129-1997 (Smoking Room Testing). Will the ratio of 15,795 sq ft enclosed non-smoking space : 23,295 sq ft total enclosed space be sufficient to qualify for the ETS pre-requisite? In other words, will a smoking room that comprises a fair percentage of the building\'s total floor space be within the letter of the pre-requisite given full compliance with isolated ventilation requirements?" "The prerequisite requires, ""Zero exposure of nonsmokers to ETS by prohibition of smoking in the building, OR, provide a designated smoking room designed to effectively contain, capture and remove ETS from the building"". The CIR narrative implies that the entire restaurant is being treated as a smoking room. While this approach will prevent building occupants in other spaces within the building from tobacco smoke exposure, it does not protect non-smoking restaurant patrons from smoke within the space. If smoking cannot be prohibited in the restaurant, the project team and owner may wish to consider creating a fully contained smoking section within the facility that meets the requirements set forth under the prerequisite. Applicable Internationally." "2353" "None" "X" "LEED Interpretation" "680" "2003-12-03" "New Construction, Commercial Interiors, Core and Shell, Existing Buildings" "Has USGBC established an alternative compliance path for IEQp2 in commercial office spaces? In multi-family residential buildings?" "Yes, in order to thoroughly address various building scenarios, the following option have been developed as an addendum by the LEED IEQ Technical Advisory Group, for immediate use by LEED projects. ALTERNATIVE COMPLIANCE OPTION 1: Establish negative pressure in the smoking rooms. a) Prohibit smoking in the building except in designated smoking areas b) Locate any exterior designated smoking areas at least 25 feet away from entries, outdoor air intakes and operable windows. c) Providing one or more designated smoking rooms designed to effectively contain, capture and remove ETS from the building. At a minimum, the smoking room must be directly exhausted to the outdoors with no re-circulation of ETS-containing air to the non-smoking area of the building, and enclosed with impermeable deck-to-deck partitions and operated at a negative pressure compared with the surrounding spaces of at least an average of 5 Pa (0.02 inches of water gauge) and with a minimum of 1 Pa (0.004 inches of water) when the door(s) to the smoking room are closed. d) Performance of the smoking room differential air pressures shall be verified by conducting 15 minutes of measurement, with a minimum of one measurement every 10 seconds, of the differential pressure in the smoking room with respect to each adjacent area and in each adjacent vertical chase with the doors to the smoking room closed. The testing will be conducted with each space configured for worst case conditions of transport of air from the smoking rooms to adjacent spaces. ALTERNATIVE COMPLIANCE OPTION 2 (for residential buildings only): Reduce air leakage between rooms with smoking and non-smoking areas in residential buildings. a) Prohibit smoking in all common areas of the building b) Locate any exterior designated smoking areas at least 25 feet away from entries, outdoor air intakes and operable windows opening to common areas. c) Minimize uncontrolled pathways for ETS transfer between individual residential units by sealing penetrations in walls, ceilings, and floors in the residential units, and by sealing vertical chases adjacent to the units. In addition, all doors in the residential units leading to common hallways shall be weather-stripped to minimize air leakage into the hallway. Acceptable sealing of residential units shall be demonstrated by a blower door test conducted in accordance with ASTM standard E779-99 (Determining Air Leakage Rate by Fan Pressurization) using the progressive Sampling Process for Diagnostic Testing in Figure 4-3 of Section 4.4.4 of the California 2001 Title 24 Low Rise Residential Manual - the Home Energy Rating Systems (HERS) Verification Procedure (on http://www.energy.ca.gov/title24/residential_manual, download Chapter 4). The standard is simply to be used for its sampling methodology - other administrative instructions and forms need not be used. Residential units must demonstrate less than 1.25 square inches leakage area per 100 square feet of enclosure area (i.e. sum of all wall, ceiling, and floor areas). AMENDMENT PER 10/5/04 CREDIT RULING: It is not required to weather-strip the doors connected to common hallways if hallways are positively pressurized with respect to residential units, and the following additional testing is conducted. The pressure difference shall be measured and recorded at least once every 10 seconds for at least 15 minutes; the average recorded pressure difference shall be no less than 5 Pa (0.02 inches of water gauge), with the lowest recorded pressure difference no less than 1 Pa (0.004 inches of water). Tests shall be made with all doors closed and with only those fans operating that are designed to operate continuously; occupant switch controlled fans shall not be operated during the tests. SUBMITTALS: Alter the hardcopy version of Letter Template as appropriate to reflect alternative option 1 or 2 and provide a narrative and summarized test results. Applicable Internationally." "549, 774, 922, 1083" "None" "X" "LEED Interpretation" "696" "2004-01-20" "New Construction, Commercial Interiors, Core and Shell, Existing Buildings" "A company is developing a new 71,000 square foot, one-story commercial/industrial facility. The company has established policies prohibiting smoking inside all of their facilities. For this particular project, they have designed a covered outdoor break area to be located within a long shallow alcove on the south face of the building to provide employees with a comfortable outdoor space where they can eat their lunches or convene during their scheduled breaks. The design team recognized the likelihood the space would also be used by smokers. To control the potential of tobacco smoke from disturbing non-smokers while in this area and to eliminate the possibility of tobacco smoke from entering the building, an outdoor smoke enclosure was designed. The break area alcove is enclosed on three sides by exterior building walls that extend up to the roof deck. The fourth side is open to the outdoors and a twelve-foot high soffit and the building roof above cover the alcove. The proposed smoking enclosure will be located at one end of the alcove with the exterior building walls enclosing two sides and the remaining two sides formed by an \'L-shape\' glass partition sealed to the slab, the underside of the soffit and to the building walls. This enclosure will be the only area adjacent to the building where smoking is permitted. The enclosure is accessed through a seven-foot high open doorway on the south face of the glass partition. An exhaust fan designed to remove smoke from the enclosure will be installed in the soffit and ducted to the roof more than 80 feet from the closest outside air intake. The doorway to the enclosure is located ~50 feet from closest operable window, ~33 feet from the doors through which employees will access the break area and ~23 feet from an access door to the building\'s electrical room (not a building entry). The smoking enclosure is not located near an area of high pedestrian traffic and the doorway is ~20 feet from the seating in the non-smoking break area. As noted above, the smoking enclosure is more than 25 feet from building entries, operable windows and air intakes. We have found no specific requirements for separation of outdoor smoking and non-smoking areas in the LEED Reference Guide and CIRs. The glass enclosure and exhaust fan are designed to prevent EST exposure of employees in the non-smoking break area. We feel that the proposed design meets the specific requirements and intent of the prerequisite. Do you agree?" "The above design seems to be a reasonable approach to protecting non-smokers from second hand smoke, and therefore meets the intent of the prerequisite. Be sure to include supporting documentation including drawings to demonstrate the distance between the smoking area and operable windows, doors and air uptakes in the building. Applicable Internationally." "None" "None" "X" "LEED Interpretation" "774" "2004-05-03" "New Construction, Commercial Interiors, Core and Shell, Existing Buildings" "We seek to develop a cost effective method to meet the intent of the ETS prerequisite in residential projects that do not have gasketed doorways (required by USGBC-approved alternative methodology, but not commonly used in Pacific Northwest highrise residential design). The proposed alternative relies on a combination of three strategies to meet the Intent: construction methodology, tracer gas testing, and pressure differential testing, as follows. (1) Construction All units will be constructed to function as designated smoking rooms to effectively contain ETS: - All unit perimeter walls are contiguous, from structural slab to structural slab. All leakage paths are caulked and sealed. All demising walls are of double wall construction with no continuous pathway between units. Sheetrock is continuously sealed with a flexible caulk at the floor and ceiling. All electrical and telephone outlets in demising walls are smoke sealed. - No supply ductwork pathways between units. Ductwork pathways between units are limited to central exhausted airstreams with exhaust fans operated continuously on emergency power. (2) Tracer gas testing Testing procedure will be conducted on six units as follows: - Two corner units (NW and SE) on a lower floor; - One North exposure only unit on a lower floor; - Two corner units (NW and SE) on a higher floor; - One South exposure only unit on a higher floor. With predominant site wind direction being NW (summer) and ESE (winter), these locations provide optimum testing of the impact of wind forces and stack effect on ETS contamination. Test to be performed with residential windows closed. Specific measurement methods and locations follow ASHRAE 129-1997. The objective of the test is to demonstrate the effectiveness of passive or architectural measures at preventing ETS from migrating between units. (3) Pressure differential testing Tracer gas testing will include local differential pressure testing between the test condos and the corridors. Since the corridors are the most likely path for leakage of ETS between units, corridors will be maintained at positive pressure to prevent the leakage of ETS from condos into corridors. Tracer gas testing will demonstrate that migration of ETS between adjacent condos tested is essentially zero. This will be the result of a combination of the building design and construction described above and corridor pressure difference. We will then test an additional sampling of 10% of the building condos using pressure testing only as an effective surrogate for tracer gas testing. Testing Procedure 1. Verify the following conditions at the start of the test: a. Toilet exhaust fans running; b. Dryer exhaust fans running; c. Test and adjacent condo HVAC unit supply fans running and outlets are balanced; d. Corridor Makeup air unit is running and outlets are balanced; e. Corridor life safety pressurization dampers are closed; f. All corridors doors are closed on the test floor; g. Windows are closed in the selected test spaces and adjacent units; h. Wind speed outside is greater than zero; i. Outdoor air temperature difference with indoor spaces is greater than 50% of the design value. 2. Establish stable tracer gas concentration in the test space. Provide a concentration above the test value for a minimum of 15 minutes. 3. Measure concentration of tracer gas in the corridor outside the test space. 4. Measure concentration of tracer gas in the spaces adjacent to the test space. 5. Measure pressure differential between tested condo test space and corridor. 5. Repeat for additional test spaces. CRITERIA FOR PASSING Building passes if tests show that concentration in the corridor and adjacent spaces is below one percent of the lowest stable established value maintained in the test space." "The proposed approach is not acceptable. The project team has proposed a hybrid approach, in an effort to meet the intent of the prerequisite, claiming to reduce costs associated with tracer gas testing for 10% of the units. The 12/3/03 credit ruling that provides for blower door testing resulted from a combined effort by the LEED IEQ Technical Advisory Group, national IAQ experts and users to find a more economical approach for residential projects to achieve this prerequisite. In the course of this study, the team found that the blower door test method was not only less expensive for projects, but was also readily available across the country in contrast to the tracer gas test method. The proposed approach attempts to combine methodologies approved in previous CIR rulings for both tracer gas and blower door testing procedures and reduces the quantity of units required to be tested under each procedure. The sampling sizes and testing methods approved in previous CIR rulings (dated 1/18/02 and 12/3/03) were established to provide a consistent approach that can be applied to multi-family residential projects, regardless of building type, climatic conditions or configuration. As this proposed sampling strategy applies to the building size and configuration of this particular project, but cannot be applied consistently to other multi-family residential projects with different conditions and configurations, it is not approved as an alternative approach. If customized hybrid approaches to this credit were allowed, the door would be open for all projects to propose different methods to achieve compliance. It is impossible for the USGBC to assess individual approaches for this credit on a project-by-project basis." "549, 680, 922, 1083" "None" "LEED Interpretation" "922" "2005-01-18" "New Construction, Existing Buildings, Commercial Interiors, Core and Shell, Mid-rise" "Subject: Test Sampling Criteria for Multi-family Affordable Housing Units Issue: The referenced standards for the Environmental Tobacco Control Pre-requisite include wording that raises a question about what quantity of units (sampling) are required to be tested (blower door testing) for compliance with the intent of the pre-requisite in a multi-family affordable housing building project. Context: The building consists of twenty affordable housing units: - 1st floor Retail (non-smoking) in addition to (2) units. - 2nd and 3rd floors are similar layouts and contain the remaining 18 units. - This type affordable housing building is one of multiple of this type to be constructed by this non-profit community development corporation. The affordable housing units allow smoking and propose to isolate the distribution of tobacco smoke through attention to the detailing and quality of construction of walls connecting rooms and the corridor. In addition the doors connecting to the corridor will be weather-stripped on three sides with an undercut at the base of the door. Description: The 12/3/2003 CIR under alternative compliance option 2 states ""Acceptable sealing of residential units shall be demonstrated by a blower door test conducted in accordance with ASTM standard E779-99 (Determining Air Leakage Rate by Fan Pressurization) using the progressive Sampling Process for Diagnostic Testing in Figure 4-3 of Section 4.4.4 of the California 2001 Title 24 Low Rise Residential Manual - the Home Energy Rating Systems (HERS) Verification Procedure"". - Section 4.4.4 states - ""The HERS rater shall diagnostically test and field verify the first dwelling unit of each model. To be considered the same model, dwelling units shall be in the same subdivision or multifamily housing development and have the same energy designs and features, including the same floor area and volume, for each dwelling unit, as shown on the CF-1R."" In addition the standard describes a sampling one out of every seven (rounded to the next whole number) for each model. - Section 8.1 (which section 4.4.4. references) states - ""Each dwelling unit must comply with the Standards when using this approach. When dwelling units have identical conditions the calculations can be combined. This means you will show separate compliance for all unique conditions"" The 10/5/2004 Amendment to this CIR expresses that if the doors (connected to common hallways) are not weather-stripped, additional testing is required in the corridor. The pressure difference shall be measured and recorded at least once every 10 seconds for at least 15 minutes; the average recorded pressure difference shall be no less than 5 Pa (0.02 inches of water gauge), with the lowest recorded pressure difference no less than 1 Pa (0.004 inches of water). Proposed Approach: The proposed approach based on our understanding of the criteria is: - Sampling - (3) blower door tests will be conducted following the outlined criteria for the 20 units (rounded up to the next whole number). - If test results do not meet acceptable levels, additional tests will be conducted in accordance with the referenced process procedure. - Weather-stripping is being installed at all edges of connecting doors (except at the undercut at the door sill), and we therefore assume the testing referred to in the 10/5/2004 Amendment is not required." "The sampling appears to be in compliance with the requirements established in the California 2001 Title 24 Low Rise Residential Manual - the Home Energy Rating Systems (HERS) Verification Procedure. This procedure must be clearly detailed in the project\'s application for the reviewer to understand. It is also reasonable to expect additional tests, in accordance with the referenced standard, should the results prove unsatisfactory. The requirement for weather stripping does not specifically preclude the sill from this requirement and therefore will be necessary. It is consistent throughout the contents of both alternative compliance paths and in the original credit requirement that openings in ceiling, walls, and floors must be sealed and it is consistently required that a minimum pressure differential must be maintained to achieve this credit, in the absence of weather stripping. Therefore, in this case it is not acceptable to preclude the weather stripping at the sill of the doors, unless the connecting hall is tested and proves to maintain the required positive pressure as listed in CIR 10/05/04." "549, 680, 774, 1083" "None"