In 2021, Iowa City became the first city in Iowa to require radon testing in rental housing. Under the ordinance, which took effect July 1, 2021, single-family and duplex rental properties must be tested for radon as part of the rental permit cycle, and when a test comes back at 4.0 picocuries per liter or higher, mitigation is required.
The city had good reason to act. Iowa has the highest average indoor radon levels in the country, roughly 7 in 10 Iowa homes test at or above the EPA action level, and Johnson County sits in EPA Radon Zone 1, the highest radon potential designation the EPA assigns. Radon is the second-leading cause of lung cancer overall and the leading cause among people who have never smoked, and tenants spend hundreds of hours a month breathing the air in your property.
We help Iowa City landlords and property managers handle the entire obligation: certified testing on the permit schedule, mitigation when levels are high, verification retests, and the documentation the city expects. One call covers a single duplex or an entire portfolio.
What the Iowa City Rental Radon Ordinance Requires
The ordinance applies to single-family homes and duplexes that hold a City of Iowa City rental permit. Testing is tied to the rental permit cycle, so radon compliance is not a one-time event; it recurs as your permits come up for renewal. Testing must be performed by a professional certified through the Iowa Department of Health and Human Services radon program, which is the state credential Iowa requires of anyone doing radon work for hire.
If a test result is below 4.0 pCi/L, you document the result and carry on. If it is at or above 4.0 pCi/L, the ordinance requires mitigation, which in practice means installing an active sub-slab depressurization system and retesting to confirm it worked.
Ordinance details, deadlines, and enforcement practices can change, so landlords should verify current requirements with the City of Iowa City directly. Better yet, let us track it for you. Radon compliance is our full-time work, and we keep our process aligned with what city inspections staff actually ask to see.
What Landlords Actually Have to Do, and When
In plain terms, the obligation looks like this: know when each rental permit renews, schedule a certified radon test ahead of that renewal, keep the written result, and act on it if the number is 4.0 pCi/L or higher. The test itself is a 48-hour minimum measurement under closed-house conditions, meaning windows stay shut and exterior doors are used only for normal coming and going.
Closed-house conditions are the part that trips up rentals, because tenants live there and nobody told them the basement windows need to stay closed for two days. We handle that coordination as part of the job, with written instructions to tenants and monitor placement that stays out of their way.
Given local averages, landlords should budget with the expectation that a meaningful share of properties will test high. That is not a reason to dread testing. It is a reason to plan for it, because an unplanned mitigation bill during a permit renewal is far more disruptive than one you saw coming.
Multi-Property Portfolios: Coordinated Testing Without the Headache
If you hold a dozen permits across Iowa City, radon compliance is a scheduling problem as much as a technical one. Every property has its own permit date, its own tenants, and its own access quirks. We manage portfolios by building a testing calendar around your permit renewal dates, then batching nearby properties so monitors go out and come back efficiently.
We use continuous radon monitors rather than mail-away kits, which means results are available the day the monitor is picked up, not weeks later. For a portfolio, that speed compounds: you learn quickly which properties pass, which need mitigation, and how to sequence the work.
Every test produces a written report suitable for your permit file, and we keep copies on our end as well. When the city asks for documentation, or when you sell a property and Iowa Code chapter 136B requires you to disclose known radon results, the paperwork already exists and is easy to find.
After a High Result: Mitigation and Verification
A result at or above 4.0 pCi/L starts the mitigation clock. The standard fix is active sub-slab depressurization: a suction point sealed through the slab, a vent pipe run to above the roofline, and a fan that runs continuously to pull radon out of the soil before it enters the living space. Sump pits, floor drains, foundation cracks, and crawl spaces, the usual entry routes, get sealed or tied into the system as needed.
For most single-family and duplex rentals in the area, installation costs roughly $900 to $1,400 and takes about a day. Tenants can usually stay home during the work, since it is closer to a plumbing visit than a renovation.
Mitigation is not complete until a follow-up test verifies the number actually dropped below 4.0 pCi/L. We schedule the verification retest after the system has run long enough to stabilize, and the passing result goes into the same compliance file as the original test, closing the loop for the permit cycle.
Why the Student Rental Market Makes This a Recurring Job
The University of Iowa makes Iowa City one of the most rental-heavy markets in the state, and it shapes how radon compliance plays out here. High tenant turnover, August-to-August leases, and permit cycles that keep coming around mean radon testing is a recurring line item, not a box you check once and forget.
Turnover actually creates opportunities. The gap between leases is the easiest time to test, because closed-house conditions are trivial to maintain in a vacant unit and there is no tenant coordination at all. If a property needs mitigation, an empty unit is also the easiest time to install it.
We help landlords fold radon into the same seasonal rhythm as their other turnover work. Tell us which units go vacant at the end of July, and we will have monitors placed, results returned, and any mitigation scheduled before the next lease starts.
Cost Planning and Tenant Communication
For budgeting purposes, professional testing in this market typically runs about $150 to $250 per property, and mitigation, when required, runs about $900 to $1,400. Across a portfolio, a reasonable plan is to assume every property gets tested on its permit cycle and that a majority may eventually need a mitigation system, given that roughly 7 in 10 Iowa homes test at or above the action level.
Tenant communication matters more than landlords expect. Radon comes from uranium decay in Iowa's glacial soils, not from anything wrong with your building or your maintenance, and tenants who hear that framing tend to cooperate readily. We provide simple notices you can send before testing that explain what the monitor is, why the windows need to stay closed, and that the device must not be moved.
When a property tests high and gets mitigated, tell your tenants that too. A landlord who says the property was tested under the city ordinance, a system was installed, and a retest confirmed low levels is describing a well-run rental, and in a competitive student market that is worth saying out loud.
Records to Keep, and How We Handle Compliance End-to-End
Your radon file for each property should include the test report with dates, device type, and results, the certification credentials of the tester, mitigation invoices and system details if a system was installed, and the post-mitigation verification result. Keep them for the life of the property. Test results also feed your Iowa Code 136B disclosure obligations whenever you sell.
We produce all of those records as a matter of course, and portfolio clients get them organized by property and permit date. If the city updates the ordinance or your permit timing shifts, the calendar we maintain for you shifts with it.
We serve rental owners throughout Iowa City, Coralville, North Liberty, Tiffin, Solon, University Heights, and the rest of Johnson County. If you have a permit renewal coming up, or you simply want radon off your list of things to track, send the form or call us and we will take it from here.