When planning a home renovation, most people envision upgraded finishes, improved efficiency, and a more comfortable living space. What often gets overlooked, however, is how structural changes can alter the way air moves through a house—and in turn, how those changes may influence radon levels indoors.
Radon is a gas that occurs naturally as uranium in soil and rock breaks down. It slips into homes through small openings in foundations, crawlspaces, and slabs. Because it’s colorless and odorless, it goes unnoticed until a test is performed. While discussions of radon are sometimes treated as a separate topic from renovations, the truth is that construction upgrades can unintentionally raise or lower exposure.
Why Renovations Matter
Modern renovations often focus on tightening the home’s envelope to improve energy performance. New windows, sealed ductwork, additional insulation, or even replacing flooring can change air circulation. While these upgrades help keep conditioned air inside, they may also limit natural ventilation. If radon is already seeping into the lower levels of the home, less ventilation means fewer escape routes for the gas, and levels can climb.
Similarly, changes to HVAC systems—such as upgrading to a high-efficiency unit or adding zoning—can alter the balance of pressure between rooms. A negative pressure environment in the basement, for instance, may draw more radon in through cracks and joints. What seems like a purely mechanical improvement may shift the way the home “breathes” in ways that aren’t obvious without testing.
Renovations That May Reduce Risk
On the other hand, not all changes increase exposure. Sealing gaps in the foundation, adding sub-slab barriers during a basement remodel, or improving ventilation in crawlspaces can reduce the entry points and dilute concentrations. When incorporated thoughtfully, upgrades can work hand-in-hand with radon mitigation strategies.
For example, homeowners finishing a basement often take steps to waterproof walls and floors. If those same sealants are applied with radon in mind, they can serve a dual purpose—blocking moisture and limiting radon infiltration. Adding a passive or active sub-slab depressurization system during major work can also be much easier and more cost-effective than retrofitting later.
A Smart Step Before and After Work
The best way to safeguard indoor air quality during a renovation is simple: test before and after. A pre-renovation test gives a baseline, and a follow-up after work is complete shows whether changes had an unintended effect. Because radon levels fluctuate seasonally, it’s wise to test at different times of year or consider a continuous monitor if the home is in an area with known concerns.
The Takeaway
Renovations are about more than what you see once the work is done. Behind the paint, flooring, and fixtures, the way a house exchanges air has just as much impact on comfort and health. By pairing your renovation plans with an awareness of radon and indoor air quality, you not only improve the look of your home—you also preserve the safety of everyone who lives there.