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LEED v4
Retail – Commercial Interiors
Indoor Environmental Quality

Minimum indoor air quality performance

LEED CREDIT

Retail-CI-v4 EQp1: Minimum indoor air quality performance Required

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Requirements

Meet the requirements for both ventilation and monitoring.

Ventilation
Mechanically ventilated spaces

For mechanically ventilated spaces (and for mixed-mode systems when the mechanical ventilation is activated), chose one of the following cases.

Case 1. Systems able to meet required outdoor airflow rates
Option 1. ASHRAE Standard 62.1–2010

Determine the minimum outdoor air intake flow for mechanical ventilation systems using the ventilation rate procedure from ASHRAE 62.1–2010 or a local equivalent, whichever is more stringent and meet the minimum requirements of ASHRAE Standard 62.1–2010, Sections 4–7, Ventilation for Acceptable Indoor Air Quality (with errata), or a local equivalent, whichever is more stringent.

Option 2. CEN Standards EN 15251–2007 and EN 13779–2007

Projects outside the U.S. may instead meet the minimum outdoor air requirements of Annex B of Comité Européen de Normalisation (CEN) Standard EN 15251–2007, Indoor environmental input parameters for design and assessment of energy performance of buildings addressing indoor air quality, thermal environment, lighting and acoustics; and meet the requirements of CEN Standard EN 13779–2007, Ventilation for nonresidential buildings, Performance requirements for ventilation and room conditioning systems, excluding Section 7.3, Thermal environment; 7.6, Acoustic environment; A.16; and A.17.

Case 2. Systems unable to meet required outdoor airflow rates

If meeting the outdoor airflow rates in Case 1 is not feasible because of the physical constraints of the existing ventilation system, complete an engineering assessment of the system’s maximum outdoor air delivery rate. Supply the maximum possible to reach the minimum setpoint in Case 1 and not less than 10 cubic feet per minute (5 liters per second) of outdoor air per person.

Naturally ventilated spaces

For naturally ventilated spaces (and for mixed-mode systems when the mechanical ventilation is inactivated), determine the minimum outdoor air opening and space configuration requirements using the natural ventilation procedure from ASHRAE Standard 62.1–2010 or a local equivalent, whichever is more stringent. Confirm that natural ventilation is an effective strategy for the project by following the flow diagram in the Chartered Institution of Building Services Engineers (CIBSE) Applications Manual AM10, March 2005, Natural Ventilation in Nondomestic Buildings, Figure 2.8 and meet the requirements of ASHRAE Standard 62.1–2010, Section 4, or a local equivalent, whichever is more stringent. [Europe ACP: Arbeitsstaettenrichtlinie ASR 5] [Latin America ACP: Engineered Natural Ventilation Systems]

All spaces

The indoor air quality procedure defined in ASHRAE Standard 62.1–2010 may not be used to comply with this prerequisite.

Monitoring
Mechanically ventilated spaces

For mechanically ventilated spaces (and for mixed-mode systems when the mechanical ventilation is activated), monitor outdoor air intake flow as follows:

  • For variable air volume systems with an outdoor air intake in the project scope of work, provide a direct outdoor airflow measurement device capable of measuring the minimum outdoor air intake flow with an accuracy of +/–10% of the design minimum outdoor airflow rate, as defined by the ventilation requirements above. An alarm must indicate when the outdoor airflow value varies by 15% or more from the outdoor airflow setpoint.
  • For constant-volume systems included in the project scope of work, balance outdoor airflow to the design minimum outdoor airflow rate defined by ASHRAE Standard 62.1–2010 (with errata), or higher. Install a current transducer on the supply fan, an airflow switch, or similar monitoring device.
Naturally ventilated spaces

For naturally ventilated spaces (and for mixed-mode systems when the mechanical ventilation is inactivated), comply with at least one of the following.

  • Provide a direct exhaust airflow measurement device capable of measuring the exhaust airflow with an accuracy of +/–10% of the design minimum exhaust airflow rate. An alarm must indicate when airflow values vary by 15% or more from the exhaust airflow setpoint.
  • Provide automatic indication devices on all natural ventilation openings intended to meet the minimum opening requirements. An alarm must indicate when any one of the openings is closed during occupied hours.
  • Monitor carbon dioxide (CO2) concentrations within each thermal zone. CO2 monitors must be between 3 and 6 feet (900 and 1 800 millimeters) above the floor and within the thermal zone. CO2 monitors must have an audible or visual indicator or alert the building automation system if the sensed CO2 concentration exceeds the setpoint by more than 10%. Calculate appropriate CO2 setpoints by using the methods in ASHRAE 62.1–2010, Appendix C.

Alternative Compliance Paths (ACPs)

Europe ACP: Naturally Ventilated Spaces
Projects in Europe may use the following approach:
  • Design the spaces for natural ventilation. Consider typical site-specific local weather conditions, site location and terrain, outdoor environmental impacts (noise, car or industrial emissions, etc.), and the comfort and well-being of the occupants.
  • Perform a design study for the building owner and building users comparing the advantages and disadvantages of the natural ventilation concept with a mechanical ventilation concept.
  • Comply with the following minimum ventilation areas per person:
  • Table 1. Minimum ventilation area

    Continuous ventilation

    Intermittent ventilation

    Single-sided

    0,35 m² / person

    1,05 m² / 10 m² room area

    Cross-ventilation

    0,2 m² / person

    0,6 m² / 10 m² room area

    The provided areas are the sum of supply an exhaust areas for an applicable room depth up to 10m. For the calculations use the number of people in the ventilation zone during use. To calculate ventilation area, if the window is covered with louvers, insect screens, or otherwise obstructed, the openable area must be based on the free unobstructed area through the opening. Additionally, comply with the monitoring requirements outlined in the credit. Submittal Documentation for Europe ACP: Provide a narrative demonstrating the natural ventilation concept can contribute to the comfort and well-being of the occupants. Include the following information:
    • Design studies which compare the natural ventilation concept with a mechanical ventilation concept along with a description of the advantages and disadvantages for the building owner and building user.
    • Description of the principal natural ventilation concept (single-sided or cross-ventilation). If the design proposes a mix of the two, provide plans and/or sections with highlighted areas for each of the natural ventilation modes.
    • Description of the proposed façade openings (type of windows, louvers, etc.) and their opening mechanisms
    Latin America ACP: Engineered Natural Ventilation Systems
    Projects in Latin America may follow the Verification Protocol for Engineered Natural Ventilation Systems in Equatorial Climates and receive a design review and approval from the Colombian Professional Association of Air-conditioning, Ventilation and Refrigeration (ACAIRE).
See all forum discussions about this credit »

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Cost estimates for this credit

On each BD+C v4 credit, LEEDuser offers the wisdom of a team of architects, engineers, cost estimators, and LEED experts with hundreds of LEED projects between then. They analyzed the sustainable design strategies associated with each LEED credit, but also to assign actual costs to those strategies.

Our tab contains overall cost guidance, notes on what “soft costs” to expect, and a strategy-by-strategy breakdown of what to consider and what it might cost, in percentage premiums, actual costs, or both.

This information is also available in a full PDF download in The Cost of LEED v4 report.

Learn more about The Cost of LEED v4 »

Frequently asked questions

A building has fan-assisted ventilation and no mechanical cooling system. Does this qualify as natural ventilation?

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What options are available to mechanically ventilated projects outside the U.S. to meet this prerequisite?

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See all forum discussions about this credit »

Addenda

4/10/2020Updated: 11/12/2020
Regional ACP
Description of change:
Projects in Japan may use JIS filter standard as alternative to ASHRAE 52.2 MERV requirements, as follows:
E(4) 25%, as defined by JIS B 9908:2011 as alternative to MERV 6
E(4) 60%, as defined by JIS B 9908:2011, as alternative to MERV 8
ePM2.5 36%, as defined by JIS B 9908: 2018, as alternative to MERV 11
ePM1 49%, as defiend by JIS B 9908:2018 as alternative to MERV 13
Campus Applicable
No
Internationally Applicable:
Yes
7/8/2017Updated: 11/6/2020
Regional ACP
Description of change:
Revise the Europe ACP to the following:
"Projects in Europe may use Arbeitsstaettenrichtlinie ASR 5 or ASR A3.6 as a local equivalent to ASHRAE Standard 62.1-2010, natural ventilation procedure."
Campus Applicable
No
Internationally Applicable:
No
4/6/2018Updated: 11/6/2020
Regional ACP
Description of change:
Table 1. Minimum ventilation area


























Continuous ventilation




Intermittent ventilation




Single-sided




0,35 m² / person




1,05 m² / 10 m² room area




Cross-ventilation




0,2 m² / person




0,6 m² / 10 m² room area


Campus Applicable
No
Internationally Applicable:
No
4/6/2018Updated: 11/6/2020
Reference Guide Correction
Description of change:
Table 1. Minimum ventilation area


























Continuous ventilation




Intermittent ventilation




Single-sided




0,35 m² / person




1,05 m² / 10 m² room area




Cross-ventilation




0,2 m² / person




0,6 m² / 10 m² room area


Campus Applicable
No
Internationally Applicable:
No
4/5/2016Updated: 1/8/2020
Regional ACP
Description of change:
Under Naturally Ventilated Spaces in the rating system, add the following language: "Projects in Latin America may follow the Verification Protocol for Engineered Natural Ventilation Systems in Equatorial Climates and receive a design review and approval from the Colombian Professional Association of Air-conditioning, Ventilation and Refrigeration (ACAIRE)."
Campus Applicable
No
Internationally Applicable:
Yes
6/3/2016Updated: 6/3/2016
Form Update
Description of change:
1. Fixed bug with default values for zone population in the single zone sheet
2. Updated Table 6-3 calculation for Ev in the multiple zone sheet to not exceed 1.0 when Max Zp3. In multiple zone sheet, changed Ep from user entry to calculated value.
4. Added column for Zone outdoor airflow provided to the 100% OA and corresponding column in the summary tab (zone outdoor airflow provided meets or exceeds Voz for all zones).
5. Note added to Are you using default value for zone population to clarify default values should only be used if expected occupancy is unknown.
6. Modified rounding and decimals displayed
7. Fixed bug in summary sheet so that all systems are always displayed.
Campus Applicable
No
Internationally Applicable:
No
4/1/2015Updated: 4/7/2016
Regional ACP
Description of change:
Add the following after the text for Naturally Ventilated Spaces:

"Projects in Europe may use Arbeitsstaettenrichtlinie ASR 5 as a local equivalent to ASHRAE Standard 62.1-2010, natural ventilation procedure."
Campus Applicable
No
Internationally Applicable:
Yes
4/1/2015Updated: 4/1/2015
Reference Guide Correction
Description of change:
As of October 2014, a new calculator is available for the Minimum Indoor Air Quality Performance prerequisite. This correction includes the new calculator in the guidance for multiple-zone systems.

1. In Step-by-Step Guidance, Mechanically Ventilated Spaces (and Mixed-Mode Spaces When a Mechanical Ventilation is Active), [BD+C page 611, Step 2; ID+C page 311, Step 2; BO+M page 399, Step 4]
Replace the first sentence in last the bullet with the following: "For multiple-zone systems, use the calculator provided by USGBC or ASHRAE’s 62MZCalc Spreadsheet."

2. In Further Explanation, Calculations for Multiple-Zone Recirculating Systems [BD+C page 617; ID+C page 316; BO+M page 402]
Replace the first paragraph with the following: "Because of the complexity of the calculations for multiple-zone recirculating systems, project teams must use the calculator provided by USGBC, ASHRAE's 62MZCalc spreadsheet, or energy modeling software to perform the ventilation rate procedure calculations and determine the amount of outdoor air required at the system level."

3. In Further Explanation, Calculations for Multiple-Zone Recirculating Systems, System Ventilation Efficiency [BD+C page 617; ID+C page 317; BO+M page 402]
Replace the second and third paragraphs with the following: "The critical zone is the zone with the highest proportion of required outdoor air to provided supply air. Critical zones are often densely occupied spaces, such as conference rooms. If using the calculator provided by USGBC or ASHRAE’s 62MZCalc spreadsheet, when all zones are entered, the critical zone for the system is determined automatically.

For large projects, it may not be feasible to enter each individual zone. In these cases, the mechanical engineer can determine the outdoor air required for the system simply by identifying the potentially critical zone(s). For a detailed discussion of identifying critical zones, see ASHRAE Standard 62.1–2010, Appendix A–A3.1, Selecting Zones for Calculation, and ASHRAE 62.1–2010 User’s Manual, Example 6-L."
Campus Applicable
No
Internationally Applicable:
No
10/1/2014Updated: 2/14/2015
Form Update
Description of change:
New calculator for projects performing the ASHRAE 62.1 ventilation rate procedure calculations required for EQ Prerequisite Minimum Indoor Air Quality Performance. This optional calculator can be used for LEED 2009 and LEED v4 projects and is an alternative to the ASHRAE 62.1 62MZCalc and previous 100% outdoor air and single zone calculators.
Campus Applicable
No
Internationally Applicable:
No
7/8/2017
LEED Interpretation
Inquiry:

We are a residential project with 610 residential units, each of which is independently ventilated with a constant volume ventilation system consisting of an Energy Recovery Ventilator (ERV) that delivers 100% outdoor air. Providing outdoor air intake flow monitors for each system is excessive in this case because for smaller systems, there are no standard manufacturer monitoring device options and it is likely that the occupants of the space would readily recognize system failure. For these reasons, the project team would like to inquire if we are required to meet the monitoring requirements of this prerequisite. If so, are there alternative compliance paths available for residential projects and/or for projects with smaller ventilation systems?

Ruling:

Outdoor air intake flow monitors are not required for small systems (systems with an outdoor air intake flow of not more than 1000 cfm (472 L/s)) if the system is balanced per ASHRAE 62.1-2010, section 7.2.2 and the maintenance plan for EA prerequisite Fundamental commissioning and verification meets the requirements of ASHRAE 62.1-2010, sections 8.4.1.2 and 8.4.1.6 and includes preventative maintenance measures for the system (for example: clean, lubricate, repair, replace, or adjust components as needed).

Campus Applicable
No
Internationally Applicable:
No
7/1/2015
LEED Interpretation
Inquiry:

May we use a more current version of ASHRAE 62.1 and ASHRAE 55?

Ruling:

Yes, for ASHRAE 62.1, LEED v4 projects may use ASHRAE 62.1-2013, ASHRAE 62.1-2016 or ASHRAE 62.1-2019 in lieu of ASHRAE 62.1-2010 for EQ Prerequisite Minimum Indoor Air Quality Performance and EQ Credit Enhanced Indoor Air Quality Strategies. The same standard must be used for both credits.

LEED 2009 projects may use ASHRAE 62.1-2010, ASHRAE 62.1-2013, or ASHRAE 62.1-2016, or ASHRAE 62.1-2019 in lieu of ASHRAE 62.1-2007 for EQ Prerequisite Minimum Indoor Air Quality Performance and EQ Credit Increased Ventilation. The same standard must be used for both credits.

For ASHRAE 55, LEED v4 projects may use ASHRAE 55-2013 in lieu of ASHRAE 55-2010 for EQ Credit Thermal Comfort.

LEED 2009 projects may use ASHRAE 55-2010 or ASHRAE 55-2013 in lieu of ASHRAE 55-2004 for EQ Credit Thermal Comfort- Design.

**Updated 7/10/2020 to include ASHRAE 62.1-2016 and ASHRAE 62.1-2019 as applicable standards.**

Campus Applicable
No
Internationally Applicable:
No
10/1/2015
LEED Interpretation
Inquiry:

Can cold storage areas conditioned below 32°F (0 °C) be excluded from the minimum ventilation requirements in the prerequisite Minimum Indoor Air Quality Performance? These spaces should be excluded for three reasons, 1. There are few contaminant sources in these spaces, 2. The introduction of outside air into these spaces is problematic, and 3. The storage areas are intended for storage of frozen goods and are uninhabitable environments, only occupied occasionally and for short periods of time, as dictated by OSHA requirements.

Ruling:

Yes, frozen cold storage areas conditioned below 32 °F (0 °C) do not need to meet ASHRAE 62.1 for the purposes of the Minimum Indoor Air Quality Prerequisite. This exception is not allowed for cold storage areas that can be adjusted from below 32 °F (0 °C) to above 32 °F (0 °C). It is also not allowed if combustion equipment (such as gas-operated forklifts) is operated in the space.

Campus Applicable
No
Internationally Applicable:
No
4/9/2019
LEED Interpretation
Inquiry:

We are trying to meet the ventilation requirements for mechanically ventilated spaces via ASHRAE 62.1.-2010. It is common for buildings in our region to employ ceiling mounted VRF systems or fan coil units at perimeter zones, however, it is highly uncommon to install filters on VRF interior units or small size AC units, so a majority of manufacturers do not provide interior equipment that allows the installation of filters equivalent to MERV 6.

It is unrealistic to require MERV 6 filters for all small air flow systems due to maintenance issues for these smaller systems. Is there an alternate path available for projects with smaller ventilation systems to comply with the particulate matter filtration requirements for this prerequisite?

Ruling:

Yes, for the EQ prerequisite Minimum indoor air quality performance, small indoor fan coils such as VRF fan coils can be exempted from the ASHRAE 62.1-2010 Section 5.8 or ASHRAE 62.1-2007 Section 5.9 particulate matter removal requirements subject to the following constraints:

1. The fan coil may not introduce outside air directly from the outdoors. The fan coil must either be a 100% recirculating system, or have outside air delivered from a Dedicated Outside air system that filters the outside air.
2. The fan coil cooling capacity must not exceed 30,000 Btuh (9 kW)

Campus Applicable
No
Internationally Applicable:
Yes
10/1/2012
LEED Interpretation
Inquiry:

We are meeting the IEQp1: Minimum Indoor Air Quality Performance with Option 2, CEN standards EN 15251:2007 and EN 13779:2007. The CEN standards provide minimum outdoor air requirements for most spaces but refer to local codes for certain specialty spaces such as parking garages. To meet the intent of the prerequisite, we propose using our local code requirements for garages, which is Teil 5 Garagen (“Section 5 – Parking Garages”) of the Verordnung über Bau und Betrieb von Sonderbauten - Nordrhein-Westfalen (“Local Law of North Rhine-Westphalia for the Construction and Operation of Specialty Buildings”), dated 17 November 2009 (SBauVO). To meet this local code, our design will use demand control ventilation with carbon monoxide (CO) detectors to limit the CO concentration. Is this approach acceptable?

Ruling:

**Update 10/01/2014: Ruling has been revised
Yes, garage demand control ventilation is an acceptable ventilation approach for parking garages. This approach is acceptable for projects pursuing Option 2 (EN 15251 and EN 13779) of EQ Prerequisite Minimum Indoor Air Quality Performance as well as the hazardous exhaust requirements in EQ Credit Indoor Chemical and Pollutant Source Control. The demand control ventilation strategy must meet the following requirements:

  • • Consider the number of cars expected to be operating in the garage at any given time and the length of time a car remains in operation in the parking garage.
  • • Consider the emission rates associated with the car exhaust for the average car.
  • • Detect the primary contaminant(s) of concern in the parking garage (for example: carbon monoxide, particulates, VOCs, NO2, etc.).
  • • Modulate airflow such that contaminant levels are maintained below a specified contaminant concentration limit and corresponding exposure period. All concentration limits must be based on local code or some other cognizant authority. If the contaminant is carbon monoxide, a concentration limit of 35 ppm time-weighted average (8 hours) and levels not to exceed 50 ppm at any time is recommended.
Campus Applicable
No
Internationally Applicable:
Yes
See all forum discussions about this credit »

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Requirements

Meet the requirements for both ventilation and monitoring.

Ventilation
Mechanically ventilated spaces

For mechanically ventilated spaces (and for mixed-mode systems when the mechanical ventilation is activated), chose one of the following cases.

Case 1. Systems able to meet required outdoor airflow rates
Option 1. ASHRAE Standard 62.1–2010

Determine the minimum outdoor air intake flow for mechanical ventilation systems using the ventilation rate procedure from ASHRAE 62.1–2010 or a local equivalent, whichever is more stringent and meet the minimum requirements of ASHRAE Standard 62.1–2010, Sections 4–7, Ventilation for Acceptable Indoor Air Quality (with errata), or a local equivalent, whichever is more stringent.

Option 2. CEN Standards EN 15251–2007 and EN 13779–2007

Projects outside the U.S. may instead meet the minimum outdoor air requirements of Annex B of Comité Européen de Normalisation (CEN) Standard EN 15251–2007, Indoor environmental input parameters for design and assessment of energy performance of buildings addressing indoor air quality, thermal environment, lighting and acoustics; and meet the requirements of CEN Standard EN 13779–2007, Ventilation for nonresidential buildings, Performance requirements for ventilation and room conditioning systems, excluding Section 7.3, Thermal environment; 7.6, Acoustic environment; A.16; and A.17.

Case 2. Systems unable to meet required outdoor airflow rates

If meeting the outdoor airflow rates in Case 1 is not feasible because of the physical constraints of the existing ventilation system, complete an engineering assessment of the system’s maximum outdoor air delivery rate. Supply the maximum possible to reach the minimum setpoint in Case 1 and not less than 10 cubic feet per minute (5 liters per second) of outdoor air per person.

Naturally ventilated spaces

For naturally ventilated spaces (and for mixed-mode systems when the mechanical ventilation is inactivated), determine the minimum outdoor air opening and space configuration requirements using the natural ventilation procedure from ASHRAE Standard 62.1–2010 or a local equivalent, whichever is more stringent. Confirm that natural ventilation is an effective strategy for the project by following the flow diagram in the Chartered Institution of Building Services Engineers (CIBSE) Applications Manual AM10, March 2005, Natural Ventilation in Nondomestic Buildings, Figure 2.8 and meet the requirements of ASHRAE Standard 62.1–2010, Section 4, or a local equivalent, whichever is more stringent. [Europe ACP: Arbeitsstaettenrichtlinie ASR 5] [Latin America ACP: Engineered Natural Ventilation Systems]

All spaces

The indoor air quality procedure defined in ASHRAE Standard 62.1–2010 may not be used to comply with this prerequisite.

Monitoring
Mechanically ventilated spaces

For mechanically ventilated spaces (and for mixed-mode systems when the mechanical ventilation is activated), monitor outdoor air intake flow as follows:

  • For variable air volume systems with an outdoor air intake in the project scope of work, provide a direct outdoor airflow measurement device capable of measuring the minimum outdoor air intake flow with an accuracy of +/–10% of the design minimum outdoor airflow rate, as defined by the ventilation requirements above. An alarm must indicate when the outdoor airflow value varies by 15% or more from the outdoor airflow setpoint.
  • For constant-volume systems included in the project scope of work, balance outdoor airflow to the design minimum outdoor airflow rate defined by ASHRAE Standard 62.1–2010 (with errata), or higher. Install a current transducer on the supply fan, an airflow switch, or similar monitoring device.
Naturally ventilated spaces

For naturally ventilated spaces (and for mixed-mode systems when the mechanical ventilation is inactivated), comply with at least one of the following.

  • Provide a direct exhaust airflow measurement device capable of measuring the exhaust airflow with an accuracy of +/–10% of the design minimum exhaust airflow rate. An alarm must indicate when airflow values vary by 15% or more from the exhaust airflow setpoint.
  • Provide automatic indication devices on all natural ventilation openings intended to meet the minimum opening requirements. An alarm must indicate when any one of the openings is closed during occupied hours.
  • Monitor carbon dioxide (CO2) concentrations within each thermal zone. CO2 monitors must be between 3 and 6 feet (900 and 1 800 millimeters) above the floor and within the thermal zone. CO2 monitors must have an audible or visual indicator or alert the building automation system if the sensed CO2 concentration exceeds the setpoint by more than 10%. Calculate appropriate CO2 setpoints by using the methods in ASHRAE 62.1–2010, Appendix C.

Alternative Compliance Paths (ACPs)

Europe ACP: Naturally Ventilated Spaces
Projects in Europe may use the following approach:
  • Design the spaces for natural ventilation. Consider typical site-specific local weather conditions, site location and terrain, outdoor environmental impacts (noise, car or industrial emissions, etc.), and the comfort and well-being of the occupants.
  • Perform a design study for the building owner and building users comparing the advantages and disadvantages of the natural ventilation concept with a mechanical ventilation concept.
  • Comply with the following minimum ventilation areas per person:
  • Table 1. Minimum ventilation area

    Continuous ventilation

    Intermittent ventilation

    Single-sided

    0,35 m² / person

    1,05 m² / 10 m² room area

    Cross-ventilation

    0,2 m² / person

    0,6 m² / 10 m² room area

    The provided areas are the sum of supply an exhaust areas for an applicable room depth up to 10m. For the calculations use the number of people in the ventilation zone during use. To calculate ventilation area, if the window is covered with louvers, insect screens, or otherwise obstructed, the openable area must be based on the free unobstructed area through the opening. Additionally, comply with the monitoring requirements outlined in the credit. Submittal Documentation for Europe ACP: Provide a narrative demonstrating the natural ventilation concept can contribute to the comfort and well-being of the occupants. Include the following information:
    • Design studies which compare the natural ventilation concept with a mechanical ventilation concept along with a description of the advantages and disadvantages for the building owner and building user.
    • Description of the principal natural ventilation concept (single-sided or cross-ventilation). If the design proposes a mix of the two, provide plans and/or sections with highlighted areas for each of the natural ventilation modes.
    • Description of the proposed façade openings (type of windows, louvers, etc.) and their opening mechanisms
    Latin America ACP: Engineered Natural Ventilation Systems
    Projects in Latin America may follow the Verification Protocol for Engineered Natural Ventilation Systems in Equatorial Climates and receive a design review and approval from the Colombian Professional Association of Air-conditioning, Ventilation and Refrigeration (ACAIRE).

Cost estimates for this credit

On each BD+C v4 credit, LEEDuser offers the wisdom of a team of architects, engineers, cost estimators, and LEED experts with hundreds of LEED projects between then. They analyzed the sustainable design strategies associated with each LEED credit, but also to assign actual costs to those strategies.

Our tab contains overall cost guidance, notes on what “soft costs” to expect, and a strategy-by-strategy breakdown of what to consider and what it might cost, in percentage premiums, actual costs, or both.

This information is also available in a full PDF download in The Cost of LEED v4 report.

Learn more about The Cost of LEED v4 »

In the end, LEED is all about documentation. LEEDuser’s Documentation Toolkit, for premium members only, saves you time and helps you avoid mistakes with:

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  • Sample templates to help guide your narratives and LEED Online submissions.
  • Examples of actual submissions from certified LEED projects.

A building has fan-assisted ventilation and no mechanical cooling system. Does this qualify as natural ventilation?

The answer to this question is available to LEEDuser premium members. Start a free trial »

(If you're already a premium member, log in here.)

What options are available to mechanically ventilated projects outside the U.S. to meet this prerequisite?

The answer to this question is available to LEEDuser premium members. Start a free trial »

(If you're already a premium member, log in here.)

4/10/2020Updated: 11/12/2020
Regional ACP
Description of change:
Projects in Japan may use JIS filter standard as alternative to ASHRAE 52.2 MERV requirements, as follows:
E(4) 25%, as defined by JIS B 9908:2011 as alternative to MERV 6
E(4) 60%, as defined by JIS B 9908:2011, as alternative to MERV 8
ePM2.5 36%, as defined by JIS B 9908: 2018, as alternative to MERV 11
ePM1 49%, as defiend by JIS B 9908:2018 as alternative to MERV 13
Campus Applicable
No
Internationally Applicable:
Yes
7/8/2017Updated: 11/6/2020
Regional ACP
Description of change:
Revise the Europe ACP to the following:
"Projects in Europe may use Arbeitsstaettenrichtlinie ASR 5 or ASR A3.6 as a local equivalent to ASHRAE Standard 62.1-2010, natural ventilation procedure."
Campus Applicable
No
Internationally Applicable:
No
4/6/2018Updated: 11/6/2020
Regional ACP
Description of change:
Table 1. Minimum ventilation area


























Continuous ventilation




Intermittent ventilation




Single-sided




0,35 m² / person




1,05 m² / 10 m² room area




Cross-ventilation




0,2 m² / person




0,6 m² / 10 m² room area


Campus Applicable
No
Internationally Applicable:
No
4/6/2018Updated: 11/6/2020
Reference Guide Correction
Description of change:
Table 1. Minimum ventilation area


























Continuous ventilation




Intermittent ventilation




Single-sided




0,35 m² / person




1,05 m² / 10 m² room area




Cross-ventilation




0,2 m² / person




0,6 m² / 10 m² room area


Campus Applicable
No
Internationally Applicable:
No
4/5/2016Updated: 1/8/2020
Regional ACP
Description of change:
Under Naturally Ventilated Spaces in the rating system, add the following language: "Projects in Latin America may follow the Verification Protocol for Engineered Natural Ventilation Systems in Equatorial Climates and receive a design review and approval from the Colombian Professional Association of Air-conditioning, Ventilation and Refrigeration (ACAIRE)."
Campus Applicable
No
Internationally Applicable:
Yes
6/3/2016Updated: 6/3/2016
Form Update
Description of change:
1. Fixed bug with default values for zone population in the single zone sheet
2. Updated Table 6-3 calculation for Ev in the multiple zone sheet to not exceed 1.0 when Max Zp3. In multiple zone sheet, changed Ep from user entry to calculated value.
4. Added column for Zone outdoor airflow provided to the 100% OA and corresponding column in the summary tab (zone outdoor airflow provided meets or exceeds Voz for all zones).
5. Note added to Are you using default value for zone population to clarify default values should only be used if expected occupancy is unknown.
6. Modified rounding and decimals displayed
7. Fixed bug in summary sheet so that all systems are always displayed.
Campus Applicable
No
Internationally Applicable:
No
4/1/2015Updated: 4/7/2016
Regional ACP
Description of change:
Add the following after the text for Naturally Ventilated Spaces:

"Projects in Europe may use Arbeitsstaettenrichtlinie ASR 5 as a local equivalent to ASHRAE Standard 62.1-2010, natural ventilation procedure."
Campus Applicable
No
Internationally Applicable:
Yes
4/1/2015Updated: 4/1/2015
Reference Guide Correction
Description of change:
As of October 2014, a new calculator is available for the Minimum Indoor Air Quality Performance prerequisite. This correction includes the new calculator in the guidance for multiple-zone systems.

1. In Step-by-Step Guidance, Mechanically Ventilated Spaces (and Mixed-Mode Spaces When a Mechanical Ventilation is Active), [BD+C page 611, Step 2; ID+C page 311, Step 2; BO+M page 399, Step 4]
Replace the first sentence in last the bullet with the following: "For multiple-zone systems, use the calculator provided by USGBC or ASHRAE’s 62MZCalc Spreadsheet."

2. In Further Explanation, Calculations for Multiple-Zone Recirculating Systems [BD+C page 617; ID+C page 316; BO+M page 402]
Replace the first paragraph with the following: "Because of the complexity of the calculations for multiple-zone recirculating systems, project teams must use the calculator provided by USGBC, ASHRAE's 62MZCalc spreadsheet, or energy modeling software to perform the ventilation rate procedure calculations and determine the amount of outdoor air required at the system level."

3. In Further Explanation, Calculations for Multiple-Zone Recirculating Systems, System Ventilation Efficiency [BD+C page 617; ID+C page 317; BO+M page 402]
Replace the second and third paragraphs with the following: "The critical zone is the zone with the highest proportion of required outdoor air to provided supply air. Critical zones are often densely occupied spaces, such as conference rooms. If using the calculator provided by USGBC or ASHRAE’s 62MZCalc spreadsheet, when all zones are entered, the critical zone for the system is determined automatically.

For large projects, it may not be feasible to enter each individual zone. In these cases, the mechanical engineer can determine the outdoor air required for the system simply by identifying the potentially critical zone(s). For a detailed discussion of identifying critical zones, see ASHRAE Standard 62.1–2010, Appendix A–A3.1, Selecting Zones for Calculation, and ASHRAE 62.1–2010 User’s Manual, Example 6-L."
Campus Applicable
No
Internationally Applicable:
No
10/1/2014Updated: 2/14/2015
Form Update
Description of change:
New calculator for projects performing the ASHRAE 62.1 ventilation rate procedure calculations required for EQ Prerequisite Minimum Indoor Air Quality Performance. This optional calculator can be used for LEED 2009 and LEED v4 projects and is an alternative to the ASHRAE 62.1 62MZCalc and previous 100% outdoor air and single zone calculators.
Campus Applicable
No
Internationally Applicable:
No
7/8/2017
LEED Interpretation
Inquiry:

We are a residential project with 610 residential units, each of which is independently ventilated with a constant volume ventilation system consisting of an Energy Recovery Ventilator (ERV) that delivers 100% outdoor air. Providing outdoor air intake flow monitors for each system is excessive in this case because for smaller systems, there are no standard manufacturer monitoring device options and it is likely that the occupants of the space would readily recognize system failure. For these reasons, the project team would like to inquire if we are required to meet the monitoring requirements of this prerequisite. If so, are there alternative compliance paths available for residential projects and/or for projects with smaller ventilation systems?

Ruling:

Outdoor air intake flow monitors are not required for small systems (systems with an outdoor air intake flow of not more than 1000 cfm (472 L/s)) if the system is balanced per ASHRAE 62.1-2010, section 7.2.2 and the maintenance plan for EA prerequisite Fundamental commissioning and verification meets the requirements of ASHRAE 62.1-2010, sections 8.4.1.2 and 8.4.1.6 and includes preventative maintenance measures for the system (for example: clean, lubricate, repair, replace, or adjust components as needed).

Campus Applicable
No
Internationally Applicable:
No
7/1/2015
LEED Interpretation
Inquiry:

May we use a more current version of ASHRAE 62.1 and ASHRAE 55?

Ruling:

Yes, for ASHRAE 62.1, LEED v4 projects may use ASHRAE 62.1-2013, ASHRAE 62.1-2016 or ASHRAE 62.1-2019 in lieu of ASHRAE 62.1-2010 for EQ Prerequisite Minimum Indoor Air Quality Performance and EQ Credit Enhanced Indoor Air Quality Strategies. The same standard must be used for both credits.

LEED 2009 projects may use ASHRAE 62.1-2010, ASHRAE 62.1-2013, or ASHRAE 62.1-2016, or ASHRAE 62.1-2019 in lieu of ASHRAE 62.1-2007 for EQ Prerequisite Minimum Indoor Air Quality Performance and EQ Credit Increased Ventilation. The same standard must be used for both credits.

For ASHRAE 55, LEED v4 projects may use ASHRAE 55-2013 in lieu of ASHRAE 55-2010 for EQ Credit Thermal Comfort.

LEED 2009 projects may use ASHRAE 55-2010 or ASHRAE 55-2013 in lieu of ASHRAE 55-2004 for EQ Credit Thermal Comfort- Design.

**Updated 7/10/2020 to include ASHRAE 62.1-2016 and ASHRAE 62.1-2019 as applicable standards.**

Campus Applicable
No
Internationally Applicable:
No
10/1/2015
LEED Interpretation
Inquiry:

Can cold storage areas conditioned below 32°F (0 °C) be excluded from the minimum ventilation requirements in the prerequisite Minimum Indoor Air Quality Performance? These spaces should be excluded for three reasons, 1. There are few contaminant sources in these spaces, 2. The introduction of outside air into these spaces is problematic, and 3. The storage areas are intended for storage of frozen goods and are uninhabitable environments, only occupied occasionally and for short periods of time, as dictated by OSHA requirements.

Ruling:

Yes, frozen cold storage areas conditioned below 32 °F (0 °C) do not need to meet ASHRAE 62.1 for the purposes of the Minimum Indoor Air Quality Prerequisite. This exception is not allowed for cold storage areas that can be adjusted from below 32 °F (0 °C) to above 32 °F (0 °C). It is also not allowed if combustion equipment (such as gas-operated forklifts) is operated in the space.

Campus Applicable
No
Internationally Applicable:
No
4/9/2019
LEED Interpretation
Inquiry:

We are trying to meet the ventilation requirements for mechanically ventilated spaces via ASHRAE 62.1.-2010. It is common for buildings in our region to employ ceiling mounted VRF systems or fan coil units at perimeter zones, however, it is highly uncommon to install filters on VRF interior units or small size AC units, so a majority of manufacturers do not provide interior equipment that allows the installation of filters equivalent to MERV 6.

It is unrealistic to require MERV 6 filters for all small air flow systems due to maintenance issues for these smaller systems. Is there an alternate path available for projects with smaller ventilation systems to comply with the particulate matter filtration requirements for this prerequisite?

Ruling:

Yes, for the EQ prerequisite Minimum indoor air quality performance, small indoor fan coils such as VRF fan coils can be exempted from the ASHRAE 62.1-2010 Section 5.8 or ASHRAE 62.1-2007 Section 5.9 particulate matter removal requirements subject to the following constraints:

1. The fan coil may not introduce outside air directly from the outdoors. The fan coil must either be a 100% recirculating system, or have outside air delivered from a Dedicated Outside air system that filters the outside air.
2. The fan coil cooling capacity must not exceed 30,000 Btuh (9 kW)

Campus Applicable
No
Internationally Applicable:
Yes
10/1/2012
LEED Interpretation
Inquiry:

We are meeting the IEQp1: Minimum Indoor Air Quality Performance with Option 2, CEN standards EN 15251:2007 and EN 13779:2007. The CEN standards provide minimum outdoor air requirements for most spaces but refer to local codes for certain specialty spaces such as parking garages. To meet the intent of the prerequisite, we propose using our local code requirements for garages, which is Teil 5 Garagen (“Section 5 – Parking Garages”) of the Verordnung über Bau und Betrieb von Sonderbauten - Nordrhein-Westfalen (“Local Law of North Rhine-Westphalia for the Construction and Operation of Specialty Buildings”), dated 17 November 2009 (SBauVO). To meet this local code, our design will use demand control ventilation with carbon monoxide (CO) detectors to limit the CO concentration. Is this approach acceptable?

Ruling:

**Update 10/01/2014: Ruling has been revised
Yes, garage demand control ventilation is an acceptable ventilation approach for parking garages. This approach is acceptable for projects pursuing Option 2 (EN 15251 and EN 13779) of EQ Prerequisite Minimum Indoor Air Quality Performance as well as the hazardous exhaust requirements in EQ Credit Indoor Chemical and Pollutant Source Control. The demand control ventilation strategy must meet the following requirements:

  • • Consider the number of cars expected to be operating in the garage at any given time and the length of time a car remains in operation in the parking garage.
  • • Consider the emission rates associated with the car exhaust for the average car.
  • • Detect the primary contaminant(s) of concern in the parking garage (for example: carbon monoxide, particulates, VOCs, NO2, etc.).
  • • Modulate airflow such that contaminant levels are maintained below a specified contaminant concentration limit and corresponding exposure period. All concentration limits must be based on local code or some other cognizant authority. If the contaminant is carbon monoxide, a concentration limit of 35 ppm time-weighted average (8 hours) and levels not to exceed 50 ppm at any time is recommended.
Campus Applicable
No
Internationally Applicable:
Yes

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Senior Sustainability Manager

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