Property managers & owners

Commercial and Multifamily Radon Mitigation

Apartment buildings, commercial properties and institutional buildings are a different category of work from single-family homes — different standards, different testing design, different documentation obligations. Treating them as a large house is the most common and most expensive mistake.

Why residential assumptions do not transfer

Testing protocols, placement, timing and system design requirements written for one- and two-family dwellings do not automatically apply to multifamily, commercial, school or institutional buildings. Separate consensus standards exist for those building categories, and which one governs depends on the building type and on what the applicable jurisdiction references.
Source: ANSI/AARST Radon Standards of Practice · United States · regulation · Last verified: verification date not recorded

Confirm with a certified professional which standard applies to your specific building category before scoping testing or mitigation.

For that reason this page stays at the level of planning and process. We do not publish placement counts, timing intervals or design requirements for commercial and multifamily buildings, because those belong to the applicable standard for the specific building category — not to a general web page.

What makes these projects structurally different

FactorSingle-familyMultifamily / commercial
Testing scopeTypically one lowest lived-in level.Multiple units and occupied ground-contact spaces; scope defined by the applicable standard.
FoundationUsually one or two zones.Large or segmented slabs, multiple wings, additions and expansion joints.
HVAC interactionResidential heating and cooling.Mechanical ventilation and pressurization can dominate soil gas behaviour.
System designOne or two suction points.Often multiple zones and fans, engineered as a coordinated system.
OccupancyOne household.Tenants, staff, students or customers; access and notification planning required.
DocumentationHomeowner records.Owner, lender, insurer and sometimes regulatory reporting.

Who this typically concerns

  • Apartment building owners and multifamily portfolios.
  • Property managers responsible for tenant-occupied ground-floor units.
  • Commercial building owners with occupied below-grade or slab-on-grade space.
  • Schools and institutional facilities, where distinct standards and policies apply.
  • Buyers conducting due diligence on a commercial or multifamily acquisition.

Planning a project

  • Establish which building category the property falls into, and which standard governs.
  • Engage a professional certified in Pennsylvania with experience in that building category.
  • Define the testing scope before testing rather than sampling opportunistically.
  • Plan tenant notification and access windows in advance.
  • Expect a design phase — multi-zone buildings are engineered, not templated.
  • Budget for documentation and verification, not only for installation.
  • Plan how ongoing monitoring and periodic retesting will be handled after handover.

Verification and documentation

In a multi-unit or commercial building, verification is a records exercise as much as a technical one: which spaces were tested, under what conditions, what the system does, and what the post-mitigation measurements showed. Owners, lenders and prospective buyers will ask for exactly that file.

Post-mitigation testing concepts

Pennsylvania certification for commercial work

The Commonwealth's certification requirements apply to persons and firms performing radon services for others, subject to the exemptions in the Act and regulations. Verify current certification status — and relevant experience with your building category — before engaging a provider.

How to verify a Pennsylvania radon professional

Source: Pennsylvania Radon Certification Act (Act 43 of 1987) and 25 Pa. Code Chapter 240 · Pennsylvania · regulation · Last verified: verification date not recorded

Request commercial or multifamily quotes

Tell us the building type, number of units or floor area, and what has been tested so far. Select 'Commercial / multifamily' as your situation in the form.

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