Yes - a multifamily project constructed over a multi-car ventilated garage (active or naturally ventilated) that meets ASHRAE 62.1-2007 garage ventilation requirements is considered radon resistant construction for the purposes of this prerequisite. All of the following conditions must be met:
1. This only applies to parts of buildings that are over parking garages (i.e. not in contact with soil); and
2. The parking garage must have 0.75 CFM/square foot continuous (i.e. not demand-controlled) exhaust ventilation; and
3. Include a vestibule that provides an airlock between the garage and stairwells and adjacent occupiable spaces, or provide self-closing gasketed doors with deck-to-deck partitions or a hard lid ceiling..
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Updated 10/1/13 for rating system applicability.
Updated 10/1/14 to allow ventilated garages of any kind to be considered radon resistant construction
Updated 7/26/23 to apply to v4 and v4.1, as well as provide additional guidance to ensure radon-resistant construction over ventilated garages