Radon in Townhomes and Condos

Murfreesboro, Smyrna and La Vergne have plenty of townhomes and condos, and many owners and renters in townhomes and condos assume radon is a problem for someone else, maybe the single-family houses with basements. Radon doesn't care about the deed. Any unit that sits on soil can draw it in, and an upper unit can still pick some up through shared shafts. What's different is the process: shared slabs, fire-rated walls and an HOA that controls the exterior. We're a free referral service, not a contractor; we connect owners, boards and landlords with independent certified radon professionals.

Who should test

• Townhome owners: each townhome usually has its own ground-contact slab, so each needs its own test. Your neighbor's result doesn't predict yours; the EPA says levels vary greatly even between adjacent homes.
• Ground-floor condo owners and renters: test your unit. You're in the highest-risk position in the building.
• Upper-floor units: radon is generally lower higher up, but stairwells, elevator shafts and plumbing chases can carry soil gas upward. A free TDEC kit is an easy way to check.
• HOA boards and property managers: building-wide testing should follow ANSI/AARST MA-MFLB-2023, the national protocol for measuring radon in multifamily, school, commercial and mixed-use buildings. It replaced the older multifamily (MAMF) and large-building (MALB) standards, with compliance effective December 1, 2023.

Test the lowest lived-in level of the unit, about 20 inches above the floor, away from drafts, with windows and doors closed. In a townhome, that's often a ground-floor living room or a garage-level bedroom. Rutherford County is in EPA Zone 1, and TDEC reports about one in four homes requesting a state kit test above 4 pCi/L.

How a townhome system usually works

Many townhomes here are slab-on-grade, sometimes with a garage on the same slab. A typical system is sub-slab depressurization: a suction point through the slab, often in the garage or a closet, PVC pipe up through the garage and attic, and a fan in the attic or garage attic venting above the roof. Some designs run the pipe up an exterior wall with the fan outside. A few details are specific to attached homes:

• Fire separation. Walls between units and between the garage and living space are fire-rated. Any pipe through them has to keep that rating, and the inspector will look at it.
• Shared fill under the slab. When units sit on continuous gravel, suction in one unit can reach under its neighbor. That's not harmful, but it can mean a slightly larger fan, and it's one reason some boards prefer to treat a whole building at once.
• Electrical permits. Murfreesboro and Smyrna issue their own electrical permits; see permits in Rutherford County.

Getting HOA approval

In most associations, the exterior walls and roof are common or limited-common elements, and the governing documents require written approval for changes. Plan for it before you book an installer:

• Read your declaration and architectural guidelines for rules on exterior changes, roof penetrations and paint colors.
• Submit your test results, a sketch of the pipe route and fan location, and the exhaust location relative to windows and the roof edge.
• Ask whether the pipe can be painted to match the siding, or routed inside through the garage and attic. Interior routes are often easier to approve.
• Include the installer's national certification (NRPP or NRSB), insurance and a note about who maintains the system and the roof flashing later.
• If several owners test high, a building-wide approach under ANSI/AARST SGM-MFLB-2023, the multifamily mitigation standard, can be cheaper and tidier than separate systems.

Renters, landlords and HUD properties

If you rent, share your result with the landlord or management company; you generally can't alter the building yourself. Landlords and managers of HUD-assisted or HUD-financed properties should check HUD's radon guidance, which addresses testing and mitigation for those projects.

What it costs

A single townhome system is usually priced like a house system: Angi's 2026 national range is about $805 to $1,326, averaging about $1,043. Interior routing through a garage and attic, a second suction point or HOA-required exterior finishes can add to that. See the cost guide.

Frequently asked questions

Do I need HOA approval to install a radon system in my townhome?

Usually, if any part of the system goes on the exterior wall or through the roof, since those are typically common elements. Check your declaration and architectural guidelines and submit a written request with the pipe route and fan location.

Can my neighbor's radon system affect my unit?

Sometimes. If units share continuous fill under the slab, suction from one system can reach under the next unit and may lower its radon too. It won't raise your level.

Is radon a concern in an upper-floor condo?

Levels are usually lower on upper floors, but stairwells, elevator shafts and plumbing chases can carry soil gas upward. A short-term test is the only way to know.

What standard applies to radon testing in apartment and condo buildings?

ANSI/AARST MA-MFLB-2023 covers measurement in multifamily and mixed-use buildings, and SGM-MFLB-2023 covers mitigation. Both took effect for compliance December 1, 2023.

Where this information comes from

• AARST Consortium on National Radon Standards (ANSI/AARST standards, incl. MA-MFLB-2023 and SGM-MFLB-2023)
• HUD Exchange, Radon and HUD-Assisted Projects: Housing Basics Q&A
• U.S. EPA, A Citizen's Guide to Radon (2016 PDF, includes the myths and facts list)
• U.S. EPA, Consumer's Guide to Radon Reduction (2016 PDF)
• EPA Map of Radon Zones, county data (Rutherford County, TN: Zone 1)
• Tennessee Department of Environment and Conservation: Tennessee Radon Program
• Tennessee Radon Program free test kit request (TDEC)
• City of Murfreesboro, Residential Electrical Permit Application (2026)
• Town of Smyrna, Building Safety permits and electrical permit information
• National Radon Proficiency Program (NRPP)
• National Radon Safety Board (NRSB)
• Angi, How Much Does Radon Mitigation Cost? (2026 data)