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" "2045" "2008-02-12" "New Construction, Core and Shell, Schools - New Construction, Commercial Interiors, Existing Buildings" "Our question regards the filtration requirement for re-circulating air systems, such as VAV terminals and fan coil units, under EQc5. Per LI 5061 and LI 1795 rulings, ""Since the fan coil units re-circulate room air, they must have MERV 13 filters"", so do the VAV terminal units that re-circulate air. This conflicts with our previous understanding that the MERV13 requirement would only apply to the air handling units supplying 100% outside air - or a mix of outside and return air - to a single or several rooms. The use of MERV 13 filters is justified when HVAC systems re-circulate a part of return air - e.g. mixed return air streams from various rooms - back to different spaces. In this configuration, supply ducts of the HVAC system and return air may become contaminated by re-circulated indoor-generated pollutants. Thus, contamination generated at specific indoor locations may be spread throughout the building unless properly filtered. However, the use of MERV 13 filters cannot be justified where air is re-circulated within the room. In this configuration, there is no possibility of cross-contamination: the re-circulated air has been conditioned and returned to the same room. In general, re-circulating air units (fan coils.) are provided with MERV 6 to MERV 8 filters. Using MERV 13 would substantially increase the energy consumption to condition a space without significantly improving the indoor air quality within the space. Imposing such a requirement would also cause most commercial systems to be ineligible for achievement of this credit, and may cause the other beneficial aspects of this credit (walk-off mats and isolation of harmful contaminants) not to be incorporated. Please clarify whether MERV 13 filtration is necessary for air re-circulated within a space." "**Updated January 1, 2014\n As noted in LI 5061 and LI 1795 rulings, both outside air and re-circulated air must pass through MERV-13 filtration before being introduced into a space, even if the re-circulated air is only being returned to the space it was drawn from. If there is a source of contamination in a space, filtering the re-circulated air before re-introducing it into the space provides a more rapid method of removing the contaminants than relying on the introduction of filtered outside air alone. NOTE: UPDATED CREDIT LANGUAGE FOR 2009 STATES THAT ""PARTICLE FILTERS OF AIR CLEANING DEVICES SHALL BE PROVIDED TO CLEAN THE OUTDOOR AIR AT ANY LOCATION PRIOR TO ITS INTRODUCTION TO OCCUPIED SPACES"". REQUIREMENT FOR FILTRATION ON RETURN AIR IS NO LONGER APPLICABLE TO ANY VERSION OR ANY RATING SYSTEM. " "None" "None" "X" "LEED Interpretation" "5460" "2005-02-07" "New Construction" "A CIR ruling from 1/18/2005 (EQc5) stated that "" [i]f there is a janitorial / housekeeping room in the building then it must meet the criteria for this credit by providing the ventilation requirements and deck-to-deck partitions,"" even if the building adhered to a green housekeeping policy that required only GreenSeal-compliant cleaning materials to be used in the building. In contrast, a CIR ruling from 6/24/2003 (also EQc5), stated that ""The green housekeeping program is commendable but not directly applicable to credit achievement. However, because of this program, there does not appear to be chemical use in this building that would require a separate drainage system, and thus such a system will not be required."" Logical consistency dictates that if no drainage system is required, then no ventilation and partition requirement would be required either. We presume that simply calling the room where green housekeeping chemicals are stored a \'janitorial closet\' couldn\'t trigger the requirements -- we could simply rename the room and then our facts would be the same as the school in the 6/24/2003 ruling. Please clarify whether the 1/18/2005 ruling intended to overrule the 6/24/2003 ruling, or alternatively, please explain what would appear to be a logical inconsistency (no drains are required but ventilation and partitions are required?), or please revise the 1/18/2005 ruling to confirm that if we are using a green housekeeping policy (all GreenSeal-compliant), that this eliminates the requirement for ventilation/partitions/drainage to meet the credit intent. Also please respond to the question in the 1/18/2005 CIR whether, absent a requirement for partitions/ventilation/drains, the credit could be achieved simply with walkoff mats and entryway systems. " "The 1/18/2005 ruling is NOT intended to overrule the 6/24/2003 ruling. Two separate issues are being addressed by these two CIRs. The first one is dealing with the need for chemical mixing areas to have segregated areas with deck to deck partitions and separate outside exhaust. The second one is to do with appropriate disposal of liquid waste in spaces where water and chemical concentrate mixing occurs. In both cases, the CIRs are consistent with the Rating System and Reference Guide requirements. Green housekeeping products still contain chemicals which need to be contained and dealt with per the credit requirements (albeit at lower levels). Therefore, even if the project only uses Green Seal compliant cleaning products, it would still need to meet the criteria of providing the ventilation requirements and deck-to-deck partitions. This is also noted in the CIR ruling dated 1/24/2005 which states that ""Green housekeeping cleaners contain chemicals that need to be addressed."" This credit does NOT differentiate between rooms that store Green-Seal-compliant cleaning products and those that store industry standard products. The need for drains plumbed for appropriate disposal of liquid waste is a separate issue from the ventilation requirements. As noted in CIR ruling dated 2/18/2002, sinks that dispose of chemicals, such as detergents, which are approved by the local water treatment facility, can be part of a conventional sanitary drainage system. If greywater is being directed to re-use for irrigation or uses or to a natural wastewater treatment system, then separate plumbing would be required for disposal of conventional cleaning agents. Projects should check with their local treatment facilities to confirm what the jurisdiction requirements are for chemical disposal. In response to the question raised in CIR ruling dated 1/18/2005, a project MAY be able to meet this requirement by only providing permanent walkoff mats and entryway systems if NO chemicals (of any type) are mixed and stored on-site. If any chemicals are mixed or stored on-site, then the criteria for containment, ventilation and plumbing will apply.\n\n **Update October 1, 2013: Applicable credits have been updated." "None" "None" "X" "LEED Interpretation" "5585" "2004-11-01" "New Construction" "I am running into two interpretations for the location of the ""permanent entryway system."" One argues that the system should be outside the entry door so pollutants are scraped off and left outside the enclosed indoor space. The other argues that the system should be inside the entry because a mat outside could get wet and muddy thereby adding to the dirt and contaminants brought inside. Research on the issue has not revealed which is satisfying the intent of this point. i look forward to your interpretation." "The intent of EQc5 is to prevent contaminants from entering the building which could have an effect on the indoor air quality. However, the location of the permanent entryway system, for example grills and grates, is subjective, depending on the layout of the building. If there is a vestibule it may be appropriate to have a walk off area located within it. Also, exterior walk-off areas may be considered if the area is protected from weather. Alternatively, the walk-off area can be within the building. Applicable internationally.\n\nUPDATED October 1, 2012: Please see updated guidance for this LEED Interpretation under a LEED Interpretation Ruling 10098 posted date 8/01/2011. Projects registered on or after this date must use the new ruling." "10098, 1926" "None" "X" "LEED Interpretation" "5607" "2005-04-18" "New Construction" "In order to obtain this credit, does this apply, and if so to what extent does this apply, to school science lab classrooms? School science classrooms sometimes function as ""labs"" in the sense that chemical experiments where potentially hazardous chemicals are used are done under chemical safety hoods, which are exhausted to the outdoors. These hoods are usually operated at night to maintain the hood interior under negative pressure. Chemicals are stored in cabinets in separate rooms, (prep rooms). Sometimes, however, the classrooms are used for non-chemical-using subjects, such as physics. The questions are: 1. Do all science classrooms fall under this classification? In order to apply for this credit do we need to exhaust classroom labs? Do we need to exhaust the classroom lab if it has no chemical safety hood (examples are physics lab, earth science lab, biology lab, etc.) If distinctions can be made, to what extent must the uses of these rooms be prescribed? 2. Do the prep. Rooms fall under this classification? (Again in order to apply for this credit do we need to exhaust these rooms? Please be aware that the students usually do not have access to these rooms. They are usually locked, and any chemicals are in safety cabinets.) 3. If any of the above applies, can the exhaust rate of 0.5 cfm be reduced during unoccupied periods, such as night and week ends in order to minimize energy usage? If so, should the higher level of exhaust be tied to occupancy sensors, on a timed cycle, or manually operated?" "On page 280 of the LEED-NC v2.1 Reference Guide, under Design Approach it is noted that projects should ""physically isolate occupant activities associated with chemical use through proper design"". 1. Based on your narrative, the school science classrooms (or laboratories) with chemical safety hoods will provide negative pressure inside the hoods. It would also be reasonable to have the ""lab"" as a whole under negative pressurization. The fume hoods will most likely operate only when there is an experiment underway but for all other times having the whole lab being maintained at a negative pressure will ensure that no hazardous chemicals or fumes escape out and undermine the air quality. For EQc5, you may exclude science classrooms or regular-use classrooms that are used for non-chemical demonstrations only and that do not involve potentially hazardous chemicals. 2. The same would apply to prep rooms. Though these areas are not accessible to students, school staff will be using them and the impact on occupant health needs to be addressed. 3. All areas where chemical usage occurs must be maintained at the 0.5 cfm/ft2 exhaust rate at all times to exclude the possibility of any potential chemical fumes build up. The intent of this credit is to provide a safe and healthy indoor environment for all users, and maintaining this exhaust rate will contribute to achieving this goal. The energy penalty incurred is minimal when compared to the health benefits it affords. Note: to comply with EQp1 - and thus ASHRAE Standard 62.1-2004 - ""science-lab classrooms"" must include at least 1 cfm/ft2 exhaust airflow; make sure you consider these two credits simultaneously. Also check with the local code officials as appropriate for definitions and requirements that may affect this discussion. Applicable internationally." "None" "None" "X" "LEED Interpretation" "5609" "2004-03-08" "New Construction" "In our project - a Train Maintenance facility we have taken the following measures to ensure that there is no contamination of the interior air quality: " "The measures described in your narrative to control sources of pollution and indoor air contamination in your unique facility are acceptable for credit achievement. Be sure to provide permanent entryway systems that are appropriate for you unique building type, as the sources of contamination and operating paradigm will be different than an office building. Also, since your narrative lists ammonia and bleach as items stored in janitor\'s closets, be sure to provide separation between those two chemicals to avoid dangerous chemical reactions. Applicable internationally." "None" "None" "X" "LEED Interpretation" "5677" "2004-08-03" "New Construction" "Our building has an inverted sloped roof which is supported by structural trusses. The second floor ceiling is exposed to the underside of the roof deck and trusses. The ceiling height varies from 11\'-0"" to 25\'-0"". The height of the second floor core is 9\'-6"", which is the height of the bottom of the trusses. The copy room and janitor closet are in this core. They are exhausted separately and air is not re-circulated in these spaces. These rooms have an acoustical ceiling. Does this design meet with the requirements of EQ Credit 5 (Entryway systems have been provided)? If not is there any measure that can be taken to gain this credit such as adding a layer of gypsum board or another material to the top of these spaces? " "From the design description of the second floor core, it appears that the copy room and janitor\'s closet would not meet the credit\'s space separation requirements. Acoustical lay-in ceilings are not able to contain or adequately isolate any pollutants from leaking into other areas of the building. It would also become problematic in maintaining a negative pressure differential of 7 PA, as outlined in the credit requirements. The suggestion of incorporating a continuous hard (gypsum board) ceiling to the top of the core walls is an adequate alternative to the deck to deck separation requirement, as long as the construction methods and details demonstrate that the assembly is adequate at containing and isolating pollutants/chemicals. Applicable internationally." "None" "None" "X" "LEED Interpretation" "5687" "2005-02-22" "New Construction" "Our credit interpretation request is focused on the portion of the credit regarding indoor air quality where chemical use occurs - specifically laboratory rooms with fume hoods. We are concerned with the air quality of our employees and are taking the following measures to ensure that there is chemical-use separation between the laboratories with fume hoods and the adjacent rooms. We are proposing this design solution in lieu of gypsum board wall separations from floor to underside of structure above. The following is the design criteria for each laboratory room with a fume hood: 1. Each room will have a demountable lab wall system which has been tested and approved for Clean Room Class 10,000/ISO 7, gasketed at floor and ceiling (ceiling is at 9" "The requirements are specific to performance, not to a particular type of wall construction. The credit is achievable if the team can document that the relevant rooms provide: separate outside exhaust at a rate of at least 0.50 cubic feet per minute per square foot; no air re-circulation; and negative pressure of at least 7 PA (0.03 inches of water gauge). Applicable internationally." "None" "None" "X" "LEED Interpretation" "5696" "2004-11-01" "New Construction" "Our pair of office buildings are over 300,000 sf each with 9 stories of upper-level office space, 3 stories of below-grade structured parking, 2 stories of above-grade structured parking, and a ground-level with mixed parking, loading, retail and miscellaneous uses. In addition to the other requirements of this Credit, we have provided large areas of permanent floor grates at each building\'s main, ground-level entrance from the exterior. Our questions are as follows: (1) Must floor grates from exterior to interior space be located on the inside of the building or is the outside acceptable, especially if located under an overhang? (2) In addition to the main entries, must we also provide floor grates to the entries from the exterior into ground-level retail spaces, which comprise only about 15% of the combined ground-level floor plan? (3) Must we also provide floor grates at each building\'s ground-level interior Rear Lobby, through which users of the various parking levels must pass in order to access each building\'s main level and its elevator lobby to the 9 upper office levels of the buildings?" "(1) If there is a vestibule it may be appropriate to have a walk-off area located within it. Also, exterior walk-off areas may be considered if the area is protected from weather. Alternatively, the walk-off area can be within the building. (2) Yes. If the areas in question are areas of high volume, which it appears they would be, entryway systems would be required. (3) Yes. Since you have a high volume entrance in which people are coming from the parking garage, entryway systems are required in order to prevent the transfer of dirt to the interior of the building according to EQc5. Applicable internationally.\n\nUPDATE 10/1/12: This LEED Interpretation has been marked ""Not Applicable"" to all rating systems other than NCv2.1\nUPDATE October 1, 2012: Please see updated guidance for this LEED Interpretation under a LEED Interpretation Ruling 10098 posted date 8/01/2011. Projects registered on or after this date must use the new ruling." "10098, 1927" "None" "X" "LEED Interpretation" "5700" "2005-04-04" "New Construction" "Our project consists of a large mixed-use residential and retail building, including 240 residential units in two towers, 12 townhouses, and ground floor retail. We will provide walkoff mats at all tower and retail entryways, and any chemical mixing rooms will be designed to meet the EQc5 requirements. However, the marketing group feels that prospective owners of the townhouse units will not be excited about the prospect of permanent walkoff mats in front of their units: that they will want to select their own entryway mats, etc. Since the townhouses comprise less than 5 percent of the total occupancy of the building, we believe they don\'t fall within the definition of ""high volume entryways"" within the meaning of the EQc5 requirements. Please confirm that this assumption is correct." "The assumption that the entrances to the townhouses do not fall within the definition of ""high volume entryways"" is not correct. EQc5 CIR Ruling dated 12/21/04 states that ""In evaluating the requirements of this credit, you should focus on the frequency of use of each building entry point rather than the percentage of building occupants served. Any door that is intended to be used regularly and frequently by building occupants should be considered high volume for the purposes of this credit."" EQc5 CIR Ruling dated 07/22/03 provides additional guidance about the requirement for walk-off mats for individual residential units. It is unclear from the description of this project where the townhouses are located in the project. Based on the CIR guidance, if the townhouses have individual exterior entrances then permanent entryway systems are required. If the townhouses share an exterior entrance, this may serve as the location for the permanent entryway system as it is the primary transition space between the exterior and interior space. " "None" "None" "LEED Interpretation" "5741" "2003-07-22" "New Construction" "Our project is a university housing complex consisting of 2, 3, and 4-story apartment buildings. We would like to provide the indoor air quality benefits associated with this credit and have developed an approach to honor the credit requirements in a low-rise residential setting. The buildings are designed such that the apartment entries all face central courtyards. The only path for residents to enter the apartments is to pass through one of three entries into the central courtyard, then proceed to their ""front door"". We propose to install permanent grilles at each of the courtyard entrances, ensuring that everyone must walk over one to get to their apartment. This approach will be more effective than installing permanent mats at every door due to easier maintenance. Since there are no janitor closets, we will provide educational cards in each apartment describing environmentally preferable cleaning methods and products. Is this an acceptable approach to achieving the credit?" "The credit requires that a permanent entryway system - grills, grates, etc. to capture dirt and contaminants - be incorporated at all high volume entryways. The goal is to prevent contamination of the building interior from outdoor contaminants. From the description given, it appears that the courtyard space is an exterior area, and walking across the courtyard presents opportunity to pick up contaminants. Each apartment or common entrance on the ground floor would therefore be considered a primary exterior entrance. These entryways should be installed with permanent entryway systems in order to capture this credit. For upper level apartments serviced by individual or common outdoor stairs, a grate at the bottom of the stairs would suffice to meet this requirement, as this would be the primary transition space between the exterior and interior space. The strategy for providing educational cards is applauded but would not be a necessity to meeting the requirements if there are no chemical use rooms. Any housekeeping spaces (such as common laundry rooms) within the project would however need to meet the requirements for chemical use areas. The LEED Application Guide for Lodging is available on the USGBC website and provides guidelines for low-rise lodging facilities such as these. " "None" "None" "LEED Interpretation" "5860" "2003-06-24" "New Construction" "The intent of this credit is to avoid exposure of building occupants to potentially hazardous chemicals that adversely impact air quality. Our question is in regards to the part of the credit that requires us to ""provide drains plumbed for appropriate disposal of liquid waste in spaces where water and chemical concentrate mixing occurs."" Our project is a federally funded K-12 school for the Navajo nation. The school has adopted a green housekeeping program for the new building in accordance with the Eastern Navajo Agency\'s (ENA) Green Housekeeping Program. This program focuses on the utilization of standardized environmentally friendly institutional cleaning chemicals and enhanced custodial training using the Green Seal approved ENVIRCARE chemical line, which consists of products that are non-hazardous and have a low environmental impact. The ENA Green Housekeeping standard meets several federal mandates including Executive Order 13101 on Greening the Government through Waste Prevention, Recycling and Federal Acquisition and Section 23.703 of the Federal Acquisition Regulation which requires federal agencies to consider environmental factors when purchasing products and services. Do we still need to provide a separate drain system if the school will not be allowing toxic chemicals in the building? If the green housekeeping program in itself is insufficient to meet this credit, can we provide one sink in the building with a portable waste disposal tank? The portable tank will be a stand-alone system consisting of a sink, faucet with a self-contained pump-actuated water supply and a detachable receiving/storage tank. The tank can be easily removed from the drain, and its contents disposed of in a separate government-supplied drum. The school currently captures, stores and disposes of waste according to a government mandate, and has the operating procedures incorporated into their day to day operation. If you do allow the green housekeeping standards to apply to this credit, what additional submittals will you require? " "The green housekeeping program is commendable but not directly applicable to credit achievement. However, because of this program, there does not appear to be chemical use in this building that would require a separate drainage system, and thus such a system will not be required. Include a summary of housekeeping specifications in your LEED documentation. " "None" "None" "LEED Interpretation" "5889" "2004-08-03" "New Construction" "The program requirements for our project (a county juvenile courthouse facility) call for all high volume copiers, printers and fax machines to be located in dedicated copy/print rooms (each with deck-to-deck partitions, self-closing doors and the required separate exhaust strategy to remove contaminants from the building). All janitor rooms and housekeeping areas will also be physically separated using the above strategy. That said, there are some areas of the building (three small open office areas within the judges suites, one alcove in Intake and an open office area on the ground floor with seven workstations) where it is impractical to create a separate copy/print room. We are proposing that these areas share small convenience copiers and printers. For these areas, the Owner has agreed to purchase copiers and printers with low ozone and contaminant emissions that meet or exceed the office equipment that has been tested by the GreenGuard Environmental Institute. Based on the above, our question is as follows: What is your definition of a small ""convenience"" copier and printer, are these devices exempt from all of the requirements listed in IEQ Credit 5 (deck-to-deck partitions, self-closing doors and a separate HVAC exhaust strategy) and if the above strategy is implemented would we meet the requirements for achieving IEQ Credit 5 as it relates to housekeeping and copy/print rooms? " "From the description of the strategies incorporated, it appears the project satisfies the credit requirements. As outlined in CIR EQc5 ruling dated 09/24/01, a point can be earned if the building design incorporates a copy/print space that isolates high-volume copy/print equipment and exhausts the space in conformance to the credit requirements. Ultimately, the definition of a convenience copier or printer is left at the discretion of the design team, but they are generally the smaller printers and copiers shared by many office personnel for short print and copy jobs. Page 281 of the LEED-NC v2.1 Reference Guide simply refers them as ""small"" copiers and printers. It is recommended that the project consider the intent of the credit to ""avoid exposure of building occupants to potentially hazardous chemicals that adversely impact air quality"" when selecting the equipment, estimating the equipment\'s usage and designing the spaces. Applicable internationally." "None" "None" "X" "LEED Interpretation" "5943" "2004-12-22" "New Construction" "This Credit interpretation request pertains to EQ Credit 5, Indoor Chemical and Pollutant Source Control. Our project includes two separate areas (a data center and an equipment storage room) housing an estimated total of 160 to 200 Valve-Regulated Lead Acid (VRLA) batteries per area. These batteries are designed to emit minimal hydrogen gases while charging (up to approximately 22.2 milliliters (mL) of gases per hour per battery. This information is according to the manufacturer). The approximate maximum total off gassing rate for all the batteries is calculated to be (22.2 mL X 200 batteries =) 4440 mL, or 0.16 cubic feet, per hour. In contrast, standard open or flooded lead-acid batteries can emit up to 12,500 mL of gas per battery per hour, which would result in a total of (12,500 mL X 200 batteries =) 2,500,000 mL (2,500 Liters, or 88.3 cubic feet) off gassing per hour. (All data obtained from manufacturer\'s websites.) A Credit Interpretation Ruling dated 5-14-2001 states: ""Eliminating the pollutant source through source control rather than through isolation would achieve the intent of this credit."" Therefore our question is: Given that our proposed system will generate an estimated two-tenths of one percent of the hydrogen gas amounts generated by standard open lead-acid battery systems, would the ""chemical use"" be considered: ""controlled at the source"" and these two areas (a data center and an equipment storage room) not be required to be physically isolated (deck to deck partitions, with separate outside exhausting, no air recirculation and negative pressure) under EQ Credit 5? In addition, could this approach be considered for an Innovation Credit? " "The CIR submitted pertains to the use of low-emitting batteries in the data center and equipment storage room. The batteries being used emit significantly less gases than standard batteries. While the reduction is commendable, the project has not eliminated all off-gassing, and as such the two areas would still need to meet the requirements for \'chemical use\' areas under this credit. Applicable internationally." "None" "None" "X" "LEED Interpretation" "5958" "2005-01-18" "New Construction" "This library will have a copy area with copiers available for users of the library. They will not be \'small\' copiers as described in the LEED reference manual, but they will not be high volume copiers either (staff bulk coping is done in a central print facility in another building). These copiers are for library visitors, and will likely be used to make perhaps 100-200 copies per day. Does this copy area have to meet the separation and ventilation requirements of the credit requirement, or does it fit in the description of convenience copiers? Also, if there is no chemical use in the building (all janitorial chemicals meet the \'green housekeeping\' requirement), and the copy area doesn\'t need to be separated and ventilated per the credit requirements, can we gain this credit simply through meeting the entryway requirements?" "This issue has been largely addressed in CIR Ruling dated 8/3/04. It will be the responsibility of the design team and owner to adequately explain that the copiers are provided for their features and options, not their ability to produce high volume copy outputs. While it will not guarantee credit achievement, if the team can clearly explain the procedures in place for outsourcing their high volume copy needs and can reasonably estimate the anticipated usage of these copiers in the building, then this portion of the credit may be achievable. If there is a janitorial / housekeeping room in the building then it must meet the criteria for this credit by providing the ventilation requirements and deck-to-deck partitions. Applicable internationally." "None" "None" "X" "LEED Interpretation" "6055" "2003-11-04" "New Construction" "We have three questions related to compliance with the second part of this Credit\'s requirements in spaces where chemical use occurs: 1. Our typical strategy involves providing structural deck-to-deck partitions, as well as separate outside exhausting which will create negative pressure. The applicable spaces will not have supply ductwork, but will draw supply air through the small undercut in the door. Does this meet the Credit Requirements for physical isolation of the space? 2. In spaces where chemical use occurs, is it sufficient for the exhaust system to be tied to a switch with a requirement that the user turn it on during the chemical use, or must the exhaust be continuous? 3. A Credit Ruling dated 7/22/2003 included ""common laundry rooms"" as housekeeping areas where chemical occurs. Laundry rooms typically have both washers and dryers. When a laundry room is in use, the dryers are typically in operation, which draw room air out through their individual exhaust systems. Assuming this measure is submitted under LEED 2.0, will the dryer exhausts meet the requirements for a laundry room, or must the exhaust system be provided in a different manner?" "Your inquiry is in regards to a multi-unit residential project. The intent of this credit is to avoid exposure of building occupants to potentially hazardous chemicals that adversely impact air quality. A distinction needs to be made between the chemicals used in residential and commercial projects and the exposure to the occupants, especially in regards to laundry rooms. For example, if a laundry room is anticipated/expected to provide a dual purpose of providing the residents a space for them to do their laundry and possibly an area for custodians or building personnel to clean equipment, e.g. mops, brushes, etc., then as stated in the CIR ruling 7/22/03, the space would have to meet the chemical use requirements under LEED v2.1. Typical residential common laundry rooms do not fall under the category of rooms ""where chemical mixing occurs."" Additional information can be obtained through the LEED Application Guide for Lodging and it provides guidelines for low-rise lodging facilities. This information can be found on the USGBC website. Below are additional details to the points brought up in this inquiry: 1. The proposed ventilation strategy will not meet the requirements of this credit under LEED v2.1 unless the flow requirements are based on room size and construction. LEED v2.1 has adopted specific negative pressure requirements that must be met. The project team may choose to comply with LEED v2.0 if preferred (mixed submittals are permissible). In that case, the proposed strategy is acceptable because the room does not contain a return vent to the HVAC system. The presence of an HVAC supply duct is permissible as long as the room retains negative pressure. 2. Spaces where chemical use occurs must be continuously exhausted for LEED v2.0 and 2.1. In all probability, chemicals will be present in the room even when active mixing is not occurring and even when the room is unoccupied. In order to meet the intent of this credit, the negative pressure must be maintained at all times. 3. Typical residential common laundry rooms do not fall under the category of rooms ""where chemical mixing occurs"". Therefore most residential common laundry rooms would not have to be exhausted to meet the intent of this credit. However, if the common laundry room is used as a housekeeping area (with chemical use other than bleach), then an exhaust system separate from the dryer exhaust must be installed to meet the intent of this credit for LEED v2.0 and 2.1. The location of the dryers and relatively low exhaust flow rates from standard operation would not meet the requirements of LEED v2.1. In addition, the exhaust ductwork from individual dryers is positively pressurized. Any lint build-up at the dryer or in the exhaust line will increase the likelihood of recirculation of dryer exhaust into the Laundry space. Finally, similar to the response to item 2, in order to meet the intent of this credit, the negative pressure must be maintained at all times. " "None" "None" "LEED Interpretation" "6093" "2003-08-29" "New Construction" "With reference to IAQ Credit 5 - Indoor Chemical and Pollutant Source Control - Entryway Systems: We plan to provide walk-off mats as follows: Heavy duty berber design carpet matting, rubber backed, 38oz. yard pile weight, 100%polypropylene UV stabilized ASOTA fibers. Mats will be recessed into the concrete slab for permanent installation. Our questions: 1. Will this product/installation qualify for the LEED credit? 2. Is there a minimum size requirement, or other standard which we must meet? (The LEED template is somewhat vague on this point)" "All high-volume entryways must be addressed in order to fulfill the credit requirements. The recessed mat strategy as described qualifies as permanent entryway systems for this credit because of the permanent nature of the recessed space. Proper mat maintenance is essential for performance. Please note that grates with entrapment areas are more effective. Permanent entryway systems must be installed such that they may not be easily removed or replaced with other products that do not remove dirt and possible contaminants. A good entryway system should perform these three tasks: 1) Remove soil from the shoe. 2) Absorbs large amounts of dirt, slowing the rate of transfer onto interior carpet or surfaces. 3) Absorbs excess moisture from wet shoes, thereby reducing soiling on the interior carpet or surfaces. The LEED Rating System has not set any size requirements for these entryway systems. As a recommended minimum, the width of the mat should be equal to the width of the entryway, and the length should ensure that all foot traffic will encounter the entryway system. Applicable Internationally." "None" "None" "X"