LEED v4 BD+C Indoor Environmental Quality: 16 Points That Shape Healthy Buildings (v4, 2019 addenda)

16 points. That is what LEED v4 BD+C puts on the table in the Indoor Environmental Quality category: 16 of 110 total available points for New Construction. Miss the sDA daylight threshold and lose 2 to 3 points on the simulation option. Skip the ETS smoking-area setback and the project fails a prerequisite. This article covers LEED v4 BD+C (July 2019 addenda); LEED v4.1 is a separate version and is not covered. LEED v5 has also been released (USGBC) and is not covered. Here is what drives each point and where projects drop points already earned.

EQ numbers at a glance

Source for all credit values: LEED v4 BD+C rating system, July 2019 addenda, pp. 106-139. Schools projects also have a Minimum Acoustic Performance prerequisite.

Why does the EQ category carry 16 points?

The Indoor Environmental Quality category rewards buildings that protect occupant health through ventilation, daylight, views, acoustics and thermal comfort. LEED v4 BD+C assigns 16 of 110 points to EQ. Two prerequisites must be met before any EQ credit counts: Minimum Indoor Air Quality Performance and Environmental Tobacco Smoke Control. ASHRAE 62.1-2010 sections 4-7 set the ventilation baseline; EQ credits reward design above that floor. This article does not attempt to explain USGBC’s reasons for the 16-point allocation.

What are the 2 EQ prerequisites?

EQ prerequisites are the mandatory thresholds every LEED v4 BD+C project must clear before any EQ credit points are counted. Minimum Indoor Air Quality Performance requires mechanically ventilated spaces to meet ASHRAE 62.1-2010 sections 4-7 using the ventilation rate procedure (the IAQ procedure may not be used to comply), or local equivalent if more stringent. Projects outside the U.S. may instead meet Annex B of CEN EN 15251:2007 and EN 13779:2007. Naturally ventilated spaces use the natural ventilation procedure from ASHRAE 62.1-2010 and the CIBSE AM10 flow diagram. The prerequisite also requires outdoor air monitoring. Environmental Tobacco Smoke Control prohibits smoking inside the building and outside except in designated areas at least 25 feet (7.5 meters) from all entries, outdoor air intakes and operable windows, and requires no-smoking signage within 10 feet (3 meters) of all entrances. Contractors who install covered smoking shelters at building entries without checking the 25 ft setback fail the prerequisite. Both prerequisites carry zero credit points, and failing either one disqualifies the project from LEED certification regardless of points elsewhere.

How does the EQ Daylight credit work?

EQ Credit Daylight is worth 1-3 points. All options require manual or automatic (with manual override) glare-control devices for all regularly occupied spaces. Option 1 uses annual simulation: sDA300/50% of at least 55% of regularly occupied floor area earns 2 points and 75% earns 3 points (Healthcare: 75% = 1, 90% = 2), and annual sunlight exposure ASE1000,250 must be no more than 10%. A design that reaches sDA 75% but exceeds the ASE cap earns nothing under Option 1. Option 2 uses clear-sky illuminance calculations at the equinox (75% of area = 1 point, 90% = 2). Option 3 uses measurements (75% = 2 points, 90% = 3). There is no glazing-ratio prescriptive path in LEED v4 BD+C. Model overhangs, frits and interior shading from schematic design; adding shading after the calculations close does not satisfy the simulation requirement. See the dedicated Daylight credit article for the details.

What does the EQ views credit require?

EQ Credit Quality Views is worth 1 point for New Construction (Healthcare 1-2 points). It requires a direct line of sight to the outdoors via vision glazing for 75% of regularly occupied floor area, with a clear image of the exterior (no distorting frits, fibers, patterned glazing or added tints), and at least two of four kinds of views for that area. Views into interior atria may be used to meet up to 30% of the required area. The credit is all or nothing at the 75% level for New Construction.

How do VOC limits affect the Low-Emitting Materials credit?

EQ Low-Emitting Materials is worth 1-3 points. It covers emissions and VOC content for products inside the waterproofing membrane. For New Construction without furniture, 2 compliant categories earn 1 point, 4 earn 2 and 5 earn 3 (with furniture in scope: 3, 5 and 6). Flooring, composite wood and ceilings, walls and insulation must be 100% compliant; interior paints and adhesives must be at least 90% compliant by volume for emissions and 100% for VOC content. Emissions are tested to CDPH Standard Method v1.1-2010. A contractor-submitted adhesive that fails the VOC content rules can cost the adhesives and sealants category, so review every substitution before installation.

What do the EQ acoustic and thermal credits require?

EQ Acoustic Performance is worth 1 point for New Construction, Schools, Data Centers, Warehouses and Distribution Centers and Hospitality (Healthcare 1-2 points). New Construction projects meet HVAC background noise limits from the ASHRAE Handbook, composite STC minimums from Table 1 of the credit, and reverberation times from Table 2. Schools follow ANSI S12.60-2010 Part 1 and must also meet the Minimum Acoustic Performance prerequisite. EQ Thermal Comfort is worth 1 point and has two parts: thermal comfort design to ASHRAE 55-2010 (or ISO 7730:2005 and EN 15251:2007 as alternatives) and thermal comfort controls, meaning individual controls for at least 50% of individual occupant spaces and group controls for all shared multioccupant spaces. LEED v4 BD+C does not require an occupant survey for this credit.

How do international standards compare on indoor environmental quality?

LEED v4 BD+C lets projects outside the U.S. use CEN standards in place of ASHRAE for some EQ requirements: EN 15251:2007 and EN 13779:2007 for ventilation, and ISO 7730:2005 and EN 15251:2007 (Section A2) together for thermal comfort. EN 15251 has since been replaced by EN 16798-1:2019 as the European standard for indoor environmental input parameters; confirm with USGBC whether the newer edition is accepted before relying on it. Other national schemes and codes (BREEAM, DGNB, national building codes) have their own indoor environment requirements and are not compared here.

The part everyone gets almost right

Five mistakes to avoid on EQ credits in commercial LEED projects.

1. Modeling daylight without ASE. Teams maximize glazing to hit sDA ≥ 55% and discover too late that ASE1000,250 exceeds 10%, losing all Option 1 points. Overhangs, frits and shading devices must enter the daylight model in schematic design.

2. Allowing non-compliant adhesives on site. A compliant flooring system specified on drawings does not protect the adhesives and sealants category when the contractor’s adhesive from the submittal list fails the VOC content rules. Review every wet-applied product before installation.

3. Placing smoking shelters within 25 ft of entries. The ETS Control prerequisite requires designated smoking areas at least 25 ft (7.5 m) from all entries, outdoor air intakes and operable windows.

4. Omitting thermal comfort controls. The credit needs individual controls for at least 50% of individual occupant spaces and group controls for all shared multioccupant spaces, in addition to the ASHRAE 55-2010 design compliance.

5. Treating Quality Views as a glazing-area count. The credit needs a direct line of sight for 75% of regularly occupied floor area and two of four view types for that area, with interior atria views limited to 30% of the required area.