LEED v5 BD+C/ID+C: Indoor Environmental Quality public comments

I’m very disappointed to STILL see no LEED credit address moisture management in building envelope design.  As our industry is adding continuous insulation (for good reasons), there are more and more buildings suffering from the unintended consequences of trapped moisture due to a lack of proper hygrothermal analysis during design.  This impacts energy efficiency (wet insulation = bad insulation), material durability (wet material gets replaced more frequently), and indoor air quality (mold), and yet LEED is still completely silent on the topic of good building enclosure design.

Managing moisture through good BE design is not covered in other credits (wet insulation is not accounted for in energy models, material credits or IEQ – construction moisture management is different than what I’m talking about). 

To address this critical issue, there should be a credit (in MR or IEQ) that simply requires compliance with ASHRAE 160 for all above-grade wall and roof assemblies that cover at least 10% of their respective assembly type’s total surface area. ASHRAE 160 assesses the Mold Index value (predicted mold growth) of the critical material layers in a building enclosure assembly, and is considered the industry standard for hygrothermal analysis. It is very possible to meet IECC/ASHRAE 90.1 U-factor requirements and IBC 1404.3 vapor retarder requirements but still grow mold in walls - this is where ASHRAE 160 comes in to play, and it is also where LEED should come in to play.

Fundamental Air Quality

"Densly Occupied Spaces" should reference ASHRAE 90.1-2019, 6.4.3.7 Ventilation Controls for High-Occupancy Areas: Demand control ventilation (DCV) is required for spaces larger than 500 ft2 and with a design occupancy for ventilation of 25 people per 1000 ft2 of floor area

Regarding pre-occupancy air testing, Table 1 Number of Measurements for Pre-Occupancy Air Testing doesn't appear to appropriately address those structures that are greater than 100,000 square feet. We have participated in projects recently where the structure totalled nearly 1 million square feet. Six samples appears inadequate to reliably assess air quality within these larger buildings.

EQ Prerequisite: Building Accessibility - Please provide clarity and guidance on when exceptions will be considered, especially for small interior tenant projects in pre-ADA buildings.  Strategy 5 seems not to recognize adding separate accessible restroom(s) in lieu of renovating and reconfiguring all restrooms, the latter being overly burdensome especially for tenant projects.

Entryway Systems requiring the installation of a permanent entryway system at all regularly used exterior entrances may be a dealbreaker, but without any parameters on size/area this is an ineffective requirement and should be further developed to be effective. Agree with Emily that it may be a dealbreaker for some projects.