This credit requires compliance with a varied group of items that cumulatively help keep pollutants out of the indoor air. These requirements include self-closing doors on janitors' closets, MERVMinimum efficiency reporting value. 13 filtration on mechanical equipment, and entryway trackoff systems.
Compliance will require the coordination of team members—including the mechanical engineer, architect, plumbing engineer, and contractor—and also impact project design and operations. The basic requirements are:
In addition to tobacco smoke, covered in IEQp2, one of the greatest sources of indoor pollutants is the dirt and other contaminants brought into buildings on people’s shoes. This material is tracked through the building interior, increasing the need and frequency for cleaning, and the wear on interior finishes. Dust can also be introduced into ventilation systems and distributed throughout a building, negatively effecting indoor air quality.
While it takes a lot of coordination to meet the many credit requirements, this is generally a low-cost credit. The most significant impact may come if MERVMinimum efficiency reporting value. 13-compatible air-handling equipment is not initially specified, as redesigning mechanical systems can be costly. In some situations, especially when using heat pumps, HVAC systems cannot accept MERV 13 filters because they are not able to draw air through such a thick filter.
MERV 13 filtration results in an energy-use trade-off. While MERV 13 filters offer a greater level of air filtration and, consequently, increased indoor air quality, they also increase resistance to airflow and fan energy loads. If you can separate space conditioning from ventilation and use radiant systems for all or most of the space conditioning, you can minimize this energy penalty.
When LEED 2009 was launched, this credit included language calling for containment drains in laboratory spaces where chemicals are mixed. However, the requirement was vague and it wasn't clear how to document it. Fortunately, in the July 2010 LEED addenda issued by USGBC, this requirement was removed.
There is no definitive information from USGBC on this one way or another. It is recommended that project teams do their best to find low-emitting options for IEQc5, and that IEQc4.3 compliance is recommended.
However, LEEDuser has heard that project teams have had success not including track-off mats, such as the type with grilles and small strips of carpeting. Also, mats that are removed for cleaning are not permanently installed and thus not subject to credit requirements. If used as track-off surfaces, carpet tiles should be certified, however, and are available with the requisite certifications.
There is not an official glossary definition that LEEDuser is aware of. However, various references indicate that LEED views "high volume" as one or more printers in an area totaling more than 40,000 copies (20,000 double sided) per month. The number is based on "expected" use, not capacity. This definition can be found in LEED InterpretationLEED Interpretations are official answers to technical inquiries about implementing LEED on a project. They help people understand how their projects can meet LEED requirements and provide clarity on existing options. LEED Interpretations are to be used by any project certifying under an applicable rating system. All project teams are required to adhere to all LEED Interpretations posted before their registration date. This also applies to other addenda. Adherence to rulings posted after a project registers is optional, but strongly encouraged. LEED Interpretations are published in a searchable database at usgbc.org. #1938 issued 1/7/2008, for example, and although that Interpretation is not applicable to LEED 2009, the number 40,000 has appeared in enough places that we view it as a solid number.
If the copiers print less than 40,000 pages/month (20,000 pages double-sided) you do not need to install dedicated exhaust, self-closing doors and deck-to-deck partitions. Additionally, if you use printers that do not emit VOC’s or other harmful contaminants into the indoor environment, you can make a case for exemption.
LEED Interpretation #10098, dated 8/1/2011, states that "The intent for the entryway system (grilles, grates, walk-off mats) is to capture dirt and dust. An exception to the 10 foot length and/or indoor location is acceptable provided your alternative solution meets this intent and is thoroughly justified."
Project teams have been successful including exterior mats that are protected from the weather and regularly cleaned. LEEDuser has not heard of a project successfully gaining an exception to the 10-foot requirement, however. In situations where an irregular shaped mat makes sense, teams should consider whether people entering the building will travel at least 10 feet over a mat, and not be able to short-circuit it. A short narrative explaining the impediments and how your solution meets the standard established by the LEED Interpretation is recommended.
These entrances are those that are used by building occupants on a regular basis. If your project has unique circumstances where certain building entrances are not regularly used or do not serve building occupants, they may be excluded. For example, emergency exits that are not used as regular entrances can often be excluded.
LEED Interpretation #5266 made on 05/30/2007 states that the requirements are applicable only to entrances from the outdoors.
Yes, carpet tile applies per LEED Interpretation Ruling #10252. Some project teams have preferred to use carpet tile due to ease of maintenance and avoidance of trip hazards. The carpet tile must be specifically designed for entryway systems. Regular carpeting that is not designed for this purpose and does not have regular cleaning is not applicable.
LEEDuser has not seen an official ruling on this, but our expert consensus is no.
One, replacing a physical control with a policy control is a bit of a downgrade. Two, 100% avoidance of hazardous chemicals in cleaning is unlikely. The green cleaning purchasing credit in EBOM, for example, considers 30% good enough to earn the credit. Also, the thresholds, categories, and standards referenced in that credit will only go so far in preventing use of any cleaning supplies that might generate gases or chemicals that should be exhausted.
Identify programming requirements for special-use spaces such as high-volume copy rooms (40,000 pages or more per month), laboratories, art rooms, chemical storage, housekeeping areas, and other spaces that may expose occupants to hazardous materials.
Identify space requirements for entryway walk-off mats. Review the impact that the required ten-foot entryway systems will have on common areas, lobbies, and other interior spaces adjacent to building entries. Remember that the entryway systems have to be installed at all regularly used entrances from exterior spaces, including entrances from a covered parking garage into the building.
The LEED Reference Guide states that entryway systems need to be on the interior of the building or in an interior vestibule. It is recommended that projects pursuing this credit with the intent of using an exterior entryway system (either permanent or rollout) consult the GBCI or your certification board via email to verify credit compliance. It is usually accepted that exterior walk-off systems are allowed if they are properly sheltered from weather; that would typically mean some kind of roof, but additional shelter may be warranted depending on local conditions.
Review the potential for using MERV 13 filtration on ventilation systems. Systems with low fan power or filtration size limits may not be able to accommodate MERV 13 filters.
If you can use radiant heating and cooling for space conditioning and separate that function from ventilation, you’ll be moving a lot less air and meeting the MERV 13 requirement won’t be nearly as big a deal, due to fewer and smaller ducts and filters.
Include mechanical engineers and design consultants for special-use spaces such as science labs early in the design process.
This is usually a low-cost credit. However, the MERV 13 filtration requirement can increase operational costs for added energy use and more frequent filter changes. If your ventilation system is not typically sized to accommodate a MERV 13 filter, you may have to choose a new system or have one custom-designed, which can add cost. Customization may include resizing ductwork, increasing fan capacity to maintain air delivery despite the added resistance of MERV 13 filtration, or other modifications to system design.
Design an adequate space for ten-foot entryway systems at all regularly accessed building entries. Evaluate all other building entrances—such as employee and service doors—for regular use, which may require entryway systems or roll-out mats.
Determine the type of entryway system that's best for your project. If you install permanent grates, grilles, or slotted entry systems, you will not be required to have a plan for cleaning, although those systems will still need periodic cleaning (less frequently than roll-off mats). However, if you decide to use rollout mats, you'll need to have a contract in place for weekly cleaning. The contract for weekly cleaning can be incorporated into any existing contract but must be clearly spelled out.
While roll-off mats are acceptable, additional documentation (service contracts and schedules) is required to confirm that the mats will be cleaned on a weekly basis. They cost more up-front, but permanent entryway systems provide better performance, require less maintenance, and are easier to document for LEED compliance.
Entryway systems should be climate-specific. For example, regions with high rainfall may choose high void-volume mats—for trapping dirt below the mat surface and fast drying. In regions where mud and snow are a greater source of contaminants, open-loop entry mats may be more appropriate.
Design in space for additional ductwork that might be needed to provide designated exhaust for all garages, high-volume copy rooms, janitors’ closets, science labs, workshops, art rooms, or any other spaces that may be used for mixing and storage of chemicals or hazardous materials. You need to design the exhaust system so that each space with hazardous material has negative pressure in respect to adjacent spaces. For each of these spaces, be sure to include self-closing doors, and deck-to-deck partitions or hard-lid ceilings.
Strategies for space planning may include:
When planning for space allocation to meet credit requirements, consider strategies like merging exhaust systems into a single, main, designated exhaust, or stacking chemical use areas over each other on different floors to minimize ductwork.
Provide adequate space for storage and containment of hazardous liquids.
Hazardous storage containers should be located in a secure area outdoors and away from air intakes.
Develop an outline of all the IEQc5 requirements that apply to your project, and confirm that the schematic design accommodates each one.
Adding ductwork to meet credit requirements can add costs; incorporate space-planning strategies to minimize this issue.
Once programming and space allocations have been determined, confirm that each of the relevant credit requirements is met, as detailed below.
Confirm that all mechanical ventilation systems can accommodate MERV 13 filtration on outdoor and make-up air supply.
If roll-out mats are used, make selections appropriate to the climate. The following specifics are also recommended in the LEED Reference Guide:
Confirm that chemical disposal areas meet local codes for separate drain lines or containment drains.
Confirm that all chemical storage areas, high-volume copy rooms, etc. have:
Locate hazardous waste storage containers away from outdoor air intakes.
Develop all required documentation for LEED submittal, including floor plans indicating locations and lengths of entryway systems, wall details (for deck-to-deck partitions), mechanical drawings showing locations of designated exhaust systems, and mechanical schedules specifying MERV 13 filtration.
For all spaces that may contain hazardous gas (such as garages, janitors' closets, and labs), calculate exhaust rates to confirm adequate negative pressurization. The pressurization requirements are:
Include credit requirements in all appropriate specification sections. Include the general requirements in Division 1 and others in specialties or furnishings (for the entryway systems) and HVAC (for filtration and other mechanical requirements).
Projects that use their own maintenance staff for regular cleaning of rollout entryway systems must provide a cleaning schedule and narrative along with their documentation.
Develop documentation customized for LEED submission—complete with LEED-related notes, callouts, and details—concurrently with the finalized construction documents.
The contractor is the signatory for IEQc5, even though it's a design credit. Have the contractor review 100% of the construction documents to confirm compliance before completing the design submittal. Otherwise, the credit may have to be deferred until the construction submittal.
Use temporary ventilation systems instead of the permanent HVAC units during construction. This prevents contamination of new ductwork during the construction process.
Use MERV 8 filtration on any permanent mechanical system equipment used during construction. This adds to construction management tasks and could easily be overlooked and lead to loss of the credit. (This requirement appears in the LEED Online credit form as of 10/09, even though it does not appear in the credit language or LEED Reference Guide.)
Make sure that compliance and coordination with this credit is called out in the IAQ management plan if your project is pursuing IEQc3.1: Construction Indoor Air Quality Management Plan—During Construction.
Ventilation and exhaust systems and proper filtration should be included in the commissioning scope for the commissioning credits EAp1 and EAc3.
Provide appropriate training for maintaining entryway systems. If roll-out mats are used, maintain a weekly schedule for cleaning.
Provide adequate training and education for all O&M and cleaning staff in appropriate handling, use, storage, and disposal of hazardous liquids.
Provide appropriate resources and training for O&M personnel to maintain mechanical equipment with MERV 13 filters.
Mechanical systems have to be commissioned to meet the commissioning prerequisite EAp1. The commissioning agent's scope should include confirming appropriate MERV ratings on filtration media and proper operation of designated exhaust systems.
Excerpted from LEED 2009 for Schools New Construction and Major Renovations
To minimize building occupant exposure to potentially hazardous particulates and chemical pollutants.
Design to minimize and control the entry of pollutants into buildings and later cross-contamination of regularly occupied areas through the following strategies:
Design facility cleaning and maintenance areas with isolated exhaust systems for contaminants. Maintain physical isolation from the rest of the regularly occupied areas of the building. Install permanent architectural entryway systems such as grills or grates to prevent occupant-borne contaminants from entering the building. Install highlevel filtration systems in air handling units processing both return air and outside supply air. Ensure that airhandling units can accommodate required filter sizes and pressure drops.
The Janitorial Products Pollution Prevention Project is a governmental and nonprofit project that provides fact sheets, tools, and links.
According to the website, IAQIndoor air quality: The quality and attributes of indoor air affecting the health and comfort building occupants. IAQ encompasses available fresh air, contaminant levels, acoustics and noise levels, lighting quality, and other factors. Design Tools for Schools “provides both detailed guidance as well as links to other information resources to help design new schools as well as repair, renovate, and maintain existing facilities. Though its primary focus is on indoor air quality, it is also intended to encourage school districts to embrace the concept of designing High Performance Schools, an integrated, whole building approach to addressing a myriad of important—and sometimes competing—priorities, such as energy efficiency, indoor air quality, daylighting, materials efficiency, and safety, and doing so in the context of tight budgets and limited staff."
Environmental Building News feature article describing the benefits and design choices for entryway walk-off systems.
Environmental Building News feature article explaining the various types of air filters, how their performance is measured, and ways to optimize their effectiveness.
Facilitiesnet article covering the basics of air filtration, drawbacks and benefits, standard practices and basic concepts.
Table of filtration efficiencies and their subsequent filtration properties and common applications. Good background on MERVMinimum efficiency reporting value. 13 filtration.
This spreadsheet categories dozens of specific space types according to how they should be applied under various IEQ credits. This document is essential if you have questions about how various unique space types should be treated.
A floor plan like this project example is required to document the presence of entryway track-off systems, length and location. Note that this sample shows six-foot entryway systems because the project predated LEED 2009. For LEED 2009, the systems need to be ten feet in length.
The following links take you to the public, informational versions of the dynamic LEED Online forms for each Schools-2009 IEQ credit. You'll need to fill out the live versions of these forms on LEED Online for each credit you hope to earn.
Version 4 forms (newest):
Version 3 forms:
These links are posted by LEEDuser with USGBC's permission. USGBC has certain usage restrictions for these forms; for more information, visit LEED Online and click "Sample Forms Download."
Documentation for this credit can be part of a Design Phase submittal.
We have a client who will do the entry mat in the main vestibule, but want a band of ceramic tile all the way around it. I seem to think the entry mat has to start right at the inside of the door frame though to meet this credit requirement and can't have that brief separation. Thoughts?
Rebecca, I don't see any issue witn this, as long as the entry mat meets the LEED specifications. I don't think it has to be literally right up against the door.
on our project we are looking at using the 10' long walk off mat, as for the width we would use a typical 4' -6' size, but thinking about it once a person walks into the space they would not walk the full 10' but walk in and either go right or left into the space..so the question: is there a width that we need to hold for the credit to apply? dont know if I am thinking to much into this but i felt i had to ask
John, I recommend to people that they should look for a mat design that keeps people walking across it for 10 feet. In your case, you may need to make the mat wide, or use furniture of some kind to keep people on track.
We have science classrooms in a new middle school. The science classrooms do not have fume hoods because no hazardous chemicals are used in these classrooms. The science classrooms are not science laboratories and we believe they should be exempt from the requirements of this credit. Has anyone had any experience with providing a distinction between a science classroom and a science laboratory?
Credit requirements seem to indicate that 10' long compliant mats are to be located at all "regularly used exterior entrances". Now, what do we need to do regarding connections to an existing building that is not part of the LEED project? We are trying to get a School Addition certified, and one of the points of entry (not the only one) to this addition is a door from the main corridor of the existing building. The existing building has mats in all its exterior entrances, but not as long as required by LEED. Do I still need to provide a 10' long mat between existing and new buildings? please take into account that this connection is purely through interior spaces.
I wouldn't think so. I have never seen them require a mat at an entry from an interior space. I would think this would hold true even if the interior space you are coming through is not LEED certified.
Well, they just did ask us that in the preliminary design review. It appears that we need to provide 10' long mats in all the interior connections to the existing building -OR- proof that all the entrances in the existing building (NOT part of leed project) have them.
I have read the reference guide time and time again and was not able to find anywhere that we were required to do so. Some covered spaces were listed, like a parking garage, etc. but they are still inherently exterior spaces. Our case is totally different, entrance is through a pretty long central interior corridor, very far from any exterior entrances. Risk of contamination is minimal, yet we are required to provide the mats. We will need to add roll-out type ones; I will let you know how it goes.
Thanks for your help.
Carpet tile is now an acceptable entryway system per LEED InterpretationLEED Interpretations are official answers to technical inquiries about implementing LEED on a project. They help people understand how their projects can meet LEED requirements and provide clarity on existing options. LEED Interpretations are to be used by any project certifying under an applicable rating system. All project teams are required to adhere to all LEED Interpretations posted before their registration date. This also applies to other addenda. Adherence to rulings posted after a project registers is optional, but strongly encouraged. LEED Interpretations are published in a searchable database at usgbc.org. Ruling ID#10252 https://www.usgbc.org/leedinterpretations/LISearch.aspx?liaccessid=10252
Carpet tile is a highly desired walk-off mat due to its ease of maintenance as compared to mechanical systems, avoidance of trip hazards associated with roll-out mats, and many other factors. Carpet tile captures and hides soil, requires minimal maintenance and helps prevent slips and falls. The solid backing prevents soil and moisture from penetrating the tile and seams. Carpet tiles allow for easy replacement of damaged tiles.
The carpet tile must be specifically designed for entryway systems, conventional carpet is not acceptable.
I'm working with a large school project seaking LEED certification. The schools has both chemistry classes and technical spaces for upper grades. These spaces are equipped with enhanced ventilation with no recirculation to deal with potential fumes from painting and chimical experiments. However, due the nature of the use and safety demands, mostly water based paints and mild chemical are used.
Should the class rooms be subject to the demand for underpressuration? Or could pressuration be handled in-room with separate supply and exhaust zones.
If so, this leads to trouble conserning reaching acoustical performance demands for corridor-classrooms walls and doors.
Chemistry class will be equipped with at least one fume cupbourd.
According to the credit requirements, science labs are subject to the pressurization requirement and must have fans to exhaust the space but separate air handling units are not required. You should be able to achieve the pressurization through whatever means you chose as long as you can show that the exhaust is sufficient enough to to meet the required .50 cfm exhaust rate and the 5 Pa pressurization differential. Hypothetically, depending on the size of the room and power of the fume hood, you may be able to meet it with fume hoods, but the reviewer would have to be satisfied that fume hoods would be used whenever chemical mixing occurs.
Numerous CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide responses and LEED Interpretations previously denied the credit where fan coil units recirculating room air for supplemental cooling in high load spaces were equipped with MERVMinimum efficiency reporting value. 8 filters and where the ventilation air was supplied directly to the space by central systems with MERV 13 filters. Language added to these responses now indicates that revised credit language for LEED 2009 removes the requirement to provide MERV 13 filters on return air. MERV 13 filtration is only required on outdoor air. Is there any reason to expect a credit application under v2.2 with fan coil units only recirculating room air and equipped with MERV 8 filters will be denied?
Fantastic question. Found another grey area in LEED. Do addenda for 2009 credits apply to credits in v2.2.
IMO you should be able to comply with the latest ruling in this case, because in this case the credits are very similar between 2009 and v2.2. Consider adding a narrative.
This is actually not a gray area, but it is an area you could try to work to your advantage.
The addendum clearly applies to v2009, not v2.2, however, you could submit a narrative or a request to get this addendum applied to your project anyway, and hope for the best—as Dylan said.
We've actually tried to get the 2009 addendum applied to a Schools 2007 project with no luck, but as Tristan says, you can always give it a shot and hope for the best!
Allison, was it for this credit specifically?
I disagree that this addendum is clearly about v2009. It may say it only applies to v2009 as a technicality, but in this case the credits have the exact same intent and practically the same language throughout.
The reason for the addendum is that it was unreasonable to expect recirculating systems (ie FCUs) to handle the static pressure from a MERVMinimum efficiency reporting value. 13 filter. If it is unreasonable for a v2009 project why would it not be unreasonable for a v2.2 project?
Due to space constraints, our vestibules were not able to be a full 10' wide between our doors, thus the recessed walkoff mats aren't 10'. Does anyone see any issue with supplimenting the distance with a roll-off mat (properly maintained of course) laid out at the other side of the vestibule? The end result would be more than 10', but it would have a couple inch "break" as you passed through the door from the vestibule into the lobby.
Renee- that shouldn't be a problem at all- we have had several similar situations and a combined length has always been accepted.
What does the Average Pressure Differencial mean and where would I find that info on the plan set for this credit?
Look for a copy room or janitor's closet. You want to find the amount of air that is regularly exhausted from those rooms. If air is also supplied into the space you need to subtract that number to find the total exhaust.
An ASHRAE equation for Pressure (∆P) in PA is:
Here is an example scenario:
3 foot wide closed door with a 0.5" undercut
∆P=5 (required for LEED)
Solve for Q (Air Flow in CFM)
Q=165.5*0.125*√5 = 46.3 CFM
In order to ensure this room has a negative 5 PA differential pressure to an adjacent space you need to have roughly 50 CFM total exhaust (Exhaust CFM - Supply CFM). Area of the room is irrelevant for this equation but for LEED and local building codes you may also need to ensure that you have at least 0.5 CFM/SF exhaust.
The door also needs to be self-closing to achieve this credit.
The requirement for walk-off mats is vague in regards to size of mat required. I think they are typically 4'x6' or in that range, does the 10 foot requirement only apply to permanently installed entryway systems? Thanks.
Hi Will, the requirement seem very vague to me. If you're using a rollout mat, the 10-foot requirement still applies. If that weren't the case, that would be a major loophole in this credit.
Q #1: We are working on design of 10-story school in downtown of the major US city. Design calls for roof play yard. Do we need to apply 10 feet rule for re-entry doors leading to elevator lobby?
Q #2: Design of another urban school calls for roof garden - do we need permanent walk-off system rules apply to re-entry from the garden?
Yes- you should plan for 10' of walk-off system at the building entries from both of these exterior spaces. The idea is to contain particles, dust and dirt before they can get in the building and since you have the opportunity to pick up dirt and debris on the roofs, walk-off surface is required.
Our LEED-Schools project has a Receiving Room with a roll-up door and a man door. Are the entryway systems required at both the roll-up and the man door?
There is also a Receiving Office located within the Receiving Room. Will this room need to be physically separated from the Receiving Room via deck-to-deck partition or a gypsum board ceiling? Should a self-closing door be specified here?
We do not typically provide entryway systems at overhead doors- just man doors.
The receiving room does not need to be separated from the receiving office unless it meets the requirement of hazardous gas or chemical areas.
All of my classrooms are entered directly off of a courtyard. So do I really need 10' of walk off mat per classroom? If so, I am thinking I will need to punt on this one. Just looking for some feedback - thanks.
The requirement is for "regularly used" entries to have the track-off mat; however that terms is not well defined. However, in this case it sounds like those entrances are regularly used and would be subject to the requirement.
Architect, Director of Sustainability
SHP Leading Design
Specifying and sizing equipment with MERV 13 filters affects both these credits.
If ventilation systems are to be used for building flush-out, they need to be sized to meet the air volume requirements of IEQc3.2 and must be compatible with MERV 13 filtration.
MERV 13 filters will increase fan energy demand as higher filtration ratings increase resistance to airflow and therefore slightly increase your energy demand.
Mechanical systems components will need to be commissioned to confirm appropriate installation of filtration media.
Additional mechanical system capacity may help meet the requirements of IEQp1. Ventilation systems must have MERV 13 filtration on all supply air.
Do you know which LEED credits have the most LEED Interpretations and addenda, and which have none? The Missing Manual does. Check here first to see where you need to update yourself, and share the link with your team.
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