Does HUD Require Radon Testing for Multifamily Properties?
HUD's radon policy is narrower than a blanket testing mandate, but for covered projects it still leaves owners needing a building-specific number — and testing is the only way to get one.
Direct answer
Not as a blanket rule, but yes for the projects it covers. HUD Notice CPD-23-103 requires radon to be addressed as part of the site contamination/environmental analysis for HUD-assisted projects that go through environmental review under 24 CFR Part 58 or Part 50. The notice doesn't say every single unit in every property must be tested — but it also says the only way to know a specific building's actual radon level is to test the indoor air, which in practice makes testing the standard path to compliance documentation.
What HUD's notice actually requires
HUD Notice CPD-23-103 ("Addressing Radon in the Environmental Review Process") directs Responsible Entities and HUD staff to consider radon exposure risk during the environmental review of covered projects — new construction, rehabilitation, and acquisition activities funded through HUD Community Planning and Development programs (CDBG, HOME, HTF, and related). The notice sets 4 pCi/L as the action level consistent with EPA guidance and states that testing is the only reliable method for determining the radon concentration in a specific building, since radon can't be seen, smelled, or tasted.
What it does not do is impose a uniform test-every-unit mandate across all federally connected housing nationwide. Applicability depends on the specific HUD program, the type of environmental review triggered, and whether the project falls under Part 58 (typically CDBG/HOME-funded, reviewed by a local Responsible Entity) or Part 50 (HUD conducts the review directly). Owners and developers working through either pathway should confirm the exact scope with their HUD field office or environmental review consultant — this page is a starting point, not a substitute for that project-specific determination.
Where testing becomes the practical answer
Even where the notice leaves room for other contamination-analysis methods, testing tends to be what actually satisfies a reviewer, for a simple reason: there is no way to estimate a specific building's indoor radon level from a map, a regional average, or a neighboring property's result. Radon levels vary building to building and even unit to unit based on foundation type, soil conditions, and ventilation, so a documented test result for the subject building is what a Responsible Entity or HUD reviewer can actually rely on in the environmental review record. If a test comes back below 4 pCi/L, that result documents that mitigation isn't required for that building under the notice; if it comes back at or above 4 pCi/L, the review record needs to show how that's being addressed.
This is also where HUD Section 232-financed nursing homes and assisted living facilities tend to need documentation most: Section 232 projects go through HUD environmental review, and radon sits alongside the other site contamination factors reviewed for those properties.
Who this applies to
- Multifamily owners and developers using HUD-assisted financing or CDBG/HOME/HTF funding
- Affordable housing operators going through Part 58 or Part 50 environmental review
- Section 232 nursing home and assisted living facility owners
- Lenders and refinance teams needing environmental review documentation
- Environmental review consultants preparing the record for a Responsible Entity
- Property managers maintaining compliance files across a portfolio
How RADON & CO fits into this
RADON & CO provides the building-specific test documentation HUD environmental reviews call for — a certified continuous radon monitor result with an electronic report suitable for inclusion in the environmental review record, for both individual buildings and multi-property portfolios. See our HUD & multifamily radon testing page for scheduling and portfolio pricing.
Frequently asked questions
Does HUD require radon testing for every unit in a multifamily property?
Not as a blanket rule. HUD Notice CPD-23-103 requires radon to be addressed in the environmental review for covered projects, but the specific testing scope depends on the program and review type — confirm the exact requirement with your HUD field office or environmental review consultant.
What radon level triggers action under HUD's policy?
4 pCi/L, consistent with the EPA action level referenced throughout HUD Notice CPD-23-103.
Does HUD's radon policy apply to nursing homes financed under Section 232?
Section 232 projects go through HUD environmental review, where radon is considered alongside other site contamination factors — see our nursing home radon testing page for details.
Official sources
- HUD Notice CPD-23-103: Addressing Radon in the Environmental Review Process
- EPA: Health Risk of Radon
- EPA: Radon Measurement
Disclaimer: This page is educational and does not replace legal, lender, HUD program, or environmental consultant guidance. Confirm project-specific environmental review requirements with your HUD field office, Responsible Entity, or environmental review consultant.