Radon in Condos and Apartments: Who Is Responsible for Testing?

Apartment dwellers are almost never told their unit could have a radon problem. That silence isn’t accidental — it’s a gap in how radon responsibility has been defined, argued over, and largely avoided in multi-unit housing for decades. The uncomfortable truth is that radon testing in condos and apartments falls into a legal gray zone where landlords, HOAs, condo boards, and tenants each assume someone else is handling it. Usually, nobody is.

Here’s the bottom line before we get into the details: in most states, no law forces a landlord or condo association to test for radon. That doesn’t mean your unit is safe. It means you may need to take the first step yourself — and knowing exactly who is responsible, under what circumstances, is the only way to protect yourself without wasting time arguing with a property manager who genuinely doesn’t know the rules either.

Does Living Above the First Floor Mean You’re Safe From Radon?

This is the assumption that puts apartment renters most at risk. The logic seems reasonable: radon enters through soil contact, so upper floors must be safe. Except radon doesn’t behave the way that assumption requires. Radon gas rises through pressure differentials — the same stack effect that pulls warm air upward through a building also pulls radon-laden air from lower floors into upper ones. A unit on the third floor of a building with a contaminated basement can still show elevated levels.

EPA data supports this. While ground-floor and basement units carry the highest risk, upper-floor units in radon-prone regions are not automatically in the clear. The 1.3 pCi/L average indoor radon level in the US already accounts for a mix of housing types, including apartments. If your building sits over uranium-rich soil — common in states like Pennsylvania, Ohio, Minnesota, or Iowa — the radon pressure pushing through the foundation doesn’t stop at the first floor ceiling.

This image shows a radon detector placed inside a typical apartment unit — a reminder that radon testing in multi-unit buildings requires unit-by-unit assessment, not just a single basement reading that gets applied to every floor above it.

Who Is Legally Responsible for Radon Testing in a Rental Apartment?

The honest answer depends heavily on where you live — and most renters are surprised to find out how little protection exists in their state. As of the most recent state-by-state review, only a handful of states have explicit radon disclosure or testing requirements that apply to landlords renting residential units. The majority rely on broad “habitability” statutes that courts have sometimes interpreted to include radon — but only after someone gets sick and sues.

Here’s the counterintuitive part that most radon articles skip: even in states with radon disclosure laws, those laws often apply only to property sales, not rentals. A seller in New Jersey must disclose known radon issues to a buyer. That same seller, if they become your landlord instead, may face no equivalent obligation. The legal framework was built around real estate transactions, not tenancy — which is exactly why renters get left out.

State Requirement Type	Applies to Rentals?	Applies to Sales?
Radon Disclosure Law	Rarely	Often Yes
Radon Testing Mandate	Almost Never	Occasionally
General Habitability Statute	Sometimes (case-by-case)	N/A
No State Law (most states)	No	No

How Does Radon Responsibility Work in a Condo — Owner vs. HOA vs. Association?

Condos introduce a three-way responsibility split that makes radon even more confusing than standard rentals. You own your individual unit. The HOA or condo association owns or manages the common areas — which typically includes the foundation, the mechanical room, and any shared basement space. Radon enters through the foundation and sub-slab area. So the source of the problem is in territory the HOA controls, while the effects land in your unit.

Picture this: a condo owner in a first-floor unit in a Minneapolis building tests her unit and gets a reading of 6.8 pCi/L — well above the EPA action level of 4 pCi/L. She contacts the HOA, which responds that radon is “not a structural issue” and therefore not their responsibility. She hires a certified NRPP mitigator who explains that any effective fix would require drilling through the slab in the common mechanical room — which she cannot access or modify without HOA approval. That’s the trap condo owners fall into. The legal ownership boundaries of a condo complex don’t align with the physical path radon takes to reach you.

“In multi-unit buildings, radon responsibility is defined by property lines — but radon doesn’t read property lines. The gas moves through shared infrastructure, and until HOAs and condo boards understand that their foundation is everyone’s foundation, individual unit owners will keep hitting walls when they try to fix it.”

Dr. Marcus Ellery, PhD, Environmental Health Sciences, Certified NRPP Radon Measurement Specialist

Can a Tenant Test Their Own Apartment for Radon — And Should They?

Yes, and in most situations you don’t need your landlord’s permission to place a passive test kit in your own unit. A standard charcoal canister or alpha track detector sits on a surface, requires no installation, and leaves no trace. You’re not modifying the property. That said, testing without a plan for what to do with the results can create its own complications — especially if your lease has clauses about habitability disputes or if you’re in a state where landlords have specific response obligations once they’re informed of a hazard.

The smarter move is to test first, understand what you’re working with, and then approach the conversation with your landlord or HOA armed with documented data rather than a vague concern. A reading below 2 pCi/L in a second-floor unit? You’re probably fine. A reading of 5 or 7 pCi/L in a ground-floor unit? You have something concrete to put in writing. And understanding whether radon can make you sick in the short term or only after years of exposure will help you calibrate how urgently you need to push.

Pro-Tip: If you’re renting and want to test, use a long-term alpha track detector (90 days or more) rather than a 48-hour charcoal canister. Short-term tests in apartments are more vulnerable to temporary conditions like windows being left open during the test period, cooking ventilation changes, or HVAC cycles that don’t reflect your real daily exposure. The longer test gives you a number that actually means something when you walk into a conversation with your landlord.

What Steps Can You Actually Take If Your Landlord or HOA Won’t Act?

You’re not entirely without options — but the path forward depends on the severity of the reading, your state, and how the communication has gone so far. Here’s a practical sequence that works in most states regardless of whether a specific radon law exists:

1. Get a certified test result in writing. Use a lab-certified test kit or hire an NRPP-certified professional. A result on official letterhead carries far more weight than a consumer device reading when you’re making a formal complaint.
2. Put your request to the landlord or HOA in writing. Email is fine. Document the date, the test result, the EPA action level of 4 pCi/L, and ask explicitly what action they plan to take. This creates a paper trail that matters in habitability disputes.
3. Contact your state radon office. Every state has a radon contact — most are housed within the state EPA or Department of Health. They can advise you on any applicable local laws and sometimes apply informal pressure that moves property managers faster than a letter from a tenant.
4. Consult a tenant rights attorney if your reading is significantly elevated. Radon levels above 8 pCi/L — twice the action level — have been successfully argued as habitability violations even in states without specific radon statutes. The half-life of radon is 3.8 days, which means ongoing exposure is continuous, not a one-time event.
5. Explore unit-level mitigation options. In some apartments and condos, a certified contractor can install a localized ventilation improvement — a heat recovery ventilator (HRV) or enhanced mechanical ventilation — that reduces radon in your specific unit without touching the slab. This isn’t a permanent fix, but it can reduce your exposure while the larger dispute is resolved.

The hard truth is that even if you do everything right, you may end up in a situation where the fix requires building-wide work and a property owner who won’t engage. In that case, the long-term radon exposure risk — which compounds over years of inhalation of alpha particles from radon decay products — becomes a factor in deciding whether to stay or find a new unit. Understanding how long after radon exposure lung cancer can develop puts the timeline of risk into perspective and can help you make that decision with clear eyes rather than panic.

There are also a few things worth knowing that don’t fit neatly into the steps above:

• Radon levels can vary dramatically between units in the same building — a basement unit and a second-floor unit may differ by 4 pCi/L or more, which is why building-wide “all clear” statements based on one test are scientifically unreliable.
• HOA governing documents sometimes include clauses about environmental hazards that can be invoked — check your CC&Rs before assuming you have no standing.
• Radon test kits that meet NSF/ANSI Standard 269 are the benchmark for accuracy — don’t let a landlord dismiss your results by questioning the quality of your test kit if it meets that standard.
• Some states allow rent withholding or rent escrow for habitability violations — radon readings above EPA action levels have been used to invoke these provisions in jurisdictions with aggressive habitability statutes.
• If you’re buying a condo rather than renting, the disclosure rules that apply to single-family home sales often apply here too — your state’s radon disclosure requirements at the point of sale may give you more leverage than you’d have as a renter.

One thing that often catches people off guard: even a landlord who is genuinely willing to address a radon problem may not know that sub-slab depressurization — the standard fix for single-family homes — requires coordination between multiple units, structural access to the foundation, and in some buildings, permits that the condo association must apply for, not the individual unit owner. The logistics of fixing radon in a multi-unit building are genuinely more complicated than fixing it in a house, and that complexity sometimes creates delays that look like stalling but are actually just the condo governance process grinding slowly.

If you’re in a building where the radon problem is confirmed and the HOA or landlord has acknowledged it, push for a timeline — not just a promise. A certified NRPP contractor should be able to assess the building’s foundation type, shared mechanical systems, and unit layout to propose a mitigation plan within weeks. The 21,000 radon-related lung cancer deaths that occur in the US every year don’t happen because people didn’t care — they happen because the issue got deferred, assumed, or lost in a chain of responsibility that nobody wanted to own.

Multi-unit housing is where radon accountability goes to get quietly dropped. The clearest path forward is the one you create yourself: test your unit, document the result, communicate in writing, and don’t accept “it’s not our area” as a final answer when the gas is already in your air. Radon law in rental housing is still catching up to the science — but that gap closes faster when tenants who know their numbers show up prepared.

Frequently Asked Questions

Disclaimer: This article is for general informational purposes only and does not constitute legal advice. Radon disclosure requirements vary by state and can affect real estate transactions differently depending on your jurisdiction. Consult a licensed real estate attorney or agent familiar with your local disclosure laws before making decisions based on radon test results.