Radon Testing in Lakewood, CO | InspectandTest
Lakewood sits in Jefferson County, which the EPA classifies as Radon Zone 1, the highest-risk category for indoor radon. That makes radon testing in Lakewood a standard precaution for buyers and owners, not an optional extra. Radon is a colorless, odorless radioactive gas that seeps from soil into homes, and the EPA sets 4 pCi/L as the action level. This guide summarizes EPA and CDPHE guidance current as of 2026. Consult your physician about health concerns and a certified measurement professional for testing decisions.
Radon testing in Lakewood: what to know
Radon forms from the natural decay of uranium in soil and rock, and the Front Range geology beneath Jefferson County produces elevated levels across much of the area. The EPA and CDPHE place Colorado predominantly in Zone 1, and the Colorado Department of Public Health and Environment reports that many homes statewide test above the 4 pCi/L action threshold. Lakewood’s foothill setting, where homes sit on or near uranium-bearing soils, keeps the risk consistently high.
Because radon enters through foundation cracks, sump pits, and slab penetrations, the basements common in Lakewood’s mid-century housing are the typical concentration point. A test measures the actual level in your home, since you cannot predict a result from the neighbor’s reading. Testing is the only way to know.
One of the most important things to understand about radon is that levels vary enormously from house to house, even on the same block. Two neighboring Lakewood homes built in the same year by the same builder can test years apart in their results, because soil composition, foundation cracks, and how the home is sealed all differ. This is why a neighbor’s clean test tells you nothing about your own home, and why the EPA recommends every home be tested regardless of what surrounding houses showed.
Radon is measured in picocuries per liter of air, written as pCi/L. The unit reflects how much radioactive decay is happening in a given volume of air. The 4 pCi/L action level is not a sharp safety line; the EPA notes that risk continues below it, and that homes testing between 2 and 4 pCi/L may still warrant mitigation. The number simply marks the point at which the EPA recommends action, and it gives buyers and sellers a common reference for negotiation.
Why Lakewood homes need radon testing
Zone 1 status is the headline reason, but housing stock reinforces it. Many Lakewood homes from the 1950s through 1970s have full basements and below-grade rooms where radon accumulates. Foundation cracks that develop from freeze-thaw cycles give the gas more entry points, and homes near Green Mountain and Glennon Heights sit on the kind of foothill soils associated with higher readings.
The EPA links long-term radon exposure to lung cancer, making it the second-leading cause after smoking. CDPHE offers discounted test kits to Colorado residents, lowering the barrier to a first measurement. To understand the broader state picture, our overview of radon in Colorado explains why the Front Range carries such consistent risk. Winterized, tightly sealed homes can show higher concentrations because reduced air exchange lets radon build up indoors.
How Lakewood’s geology drives radon
The foothills west of Lakewood are part of a geologic setting rich in the uranium-bearing rock and soil that produces radon as it decays. As the gas works its way up through soil, it finds the path of least resistance, which is often the foundation of a house sitting on top of it. Homes built into hillsides near Green Mountain, with multiple walls in contact with soil, can have more entry points than a home on a flat lot. The result is that Jefferson County, like much of the Front Range, sits squarely in the highest EPA risk zone.
Why winter readings often run high
Season matters for radon. In winter, Lakewood homes are sealed tight, furnaces run, and the stack effect, where warm air rising through the house pulls air upward, creates a slight negative pressure at the basement level. That suction draws radon-laden soil gas in through cracks and gaps. Because of this, winter short-term tests can read higher than summer tests in the same home, which is one reason long-term testing gives a more representative year-round average.
What a Lakewood radon test covers
Testing comes in short-term and long-term forms. Short-term tests, lasting 2 to 7 days under closed-house conditions, suit real-estate timelines and give a quick snapshot. Long-term tests run 90 days or more and better reflect year-round average exposure, which fluctuates with weather and season. Both measure picocuries per liter of air.
Professional measurement often uses a continuous radon monitor that logs hourly readings and resists tampering, which matters during transactions. Placement follows EPA protocol: the lowest livable level, away from drafts, with the home closed up beforehand. If your test comes back high, the next step is mitigation; our guide to how to get rid of radon explains the standard approaches. The deeper resource lives on our Colorado radon testing guide for Front Range homeowners.
Closed-house conditions are central to a valid short-term test. For at least 12 hours before and during the test, windows and exterior doors stay shut except for normal entry and exit, and whole-house fans or window air conditioners stay off. The detector sits 20 inches to 6 feet above the floor, away from drafts, exterior walls, and high humidity. These rules exist because radon concentrations respond quickly to ventilation, and an open window during a short-term test can produce an artificially low reading that masks a real problem.
For real-estate deals, the tamper-resistance of a continuous monitor is a real advantage. Because the device logs hourly readings, it shows whether a window was opened or the test was disturbed, which protects both buyer and seller from a manipulated result. A charcoal canister or alpha-track kit cannot reveal that kind of interference, which is why agents and inspectors often prefer continuous monitors for transactions in Lakewood and across the Front Range.
Radon testing cost in Lakewood
A professional short-term radon test in the Lakewood area typically costs $125 to $250, often bundled into a home inspection at a modest add-on rate. DIY test kits run about $15 to $40 plus a lab fee, and CDPHE-discounted kits can cost even less for residents. Continuous-monitor testing by a certified professional sits at the higher end because of the equipment involved.
Given Jefferson County’s Zone 1 status, testing is inexpensive relative to the health stakes and the cost of mitigation. If a result exceeds 4 pCi/L, a mitigation system typically runs $800 to $2,500 in this market. Budgeting for a test during any home purchase in Lakewood is a sensible default.
There is a sequencing logic worth following. Start with an inexpensive test, since the vast majority of the cost of dealing with radon is mitigation, not measurement. If the test comes back below 2 pCi/L, you likely need nothing further beyond periodic retesting. If it lands between 2 and 4 pCi/L, you can weigh mitigation against your own risk tolerance. If it exceeds 4 pCi/L, the EPA recommends acting, and the test result becomes the basis for a contractor’s system design. Testing first, then deciding, keeps the spending proportional to the actual situation in your home.
Lakewood regulations and disclosure
Colorado requires radon disclosure in residential real-estate transactions, and sellers must provide known radon information and an EPA radon brochure to buyers, per CDPHE guidance. The state does not license home inspectors, so for radon work look for certification through the National Radon Proficiency Program (NRPP) or the National Radon Safety Board (NRSB).
The Seller’s Property Disclosure form covers known radon test results and any installed mitigation system. Buyers should treat a missing or vague radon history as a reason to test before closing. Because Lakewood is firmly in Zone 1, a documented test protects both parties. For owners who already know they need to reduce levels, our Lakewood radon mitigation guide covers the next step.
Radon testing fits naturally into the Colorado contract’s inspection-objection period. Because a short-term test takes only a few days, it can run alongside the general home inspection while you still have the right to object. A result at or above 4 pCi/L gives a buyer grounds to request that the seller install a mitigation system, often at the seller’s expense, before closing. Many Lakewood transactions resolve radon this way, with the seller crediting or installing a system as part of the deal.
Neighborhoods and areas served
Radon testing in Lakewood covers Belmar, Green Mountain, Glennon Heights, and the foothill-adjacent neighborhoods near Bear Creek Lake. Because the whole county sits in Zone 1, no Lakewood neighborhood is presumed low-risk. Providers commonly extend service to Golden, Wheat Ridge, Morrison, and western Denver.
An inspector familiar with Jefferson County foothill geology can interpret readings and recommend placement that reflects local building styles. Buyers comparing across the metro often check nearby cities too; our Boulder radon testing guide covers a county with some of the highest readings in Colorado.
Local building styles affect where a detector should sit. A Lakewood home with a finished, occupied basement should be tested in that basement, since it is livable space where people spend time. A home with an unfinished crawl space or an unoccupied cellar is tested on the lowest level a family actually uses. Split-level and tri-level homes, common in the area’s mid-century stock, can complicate placement, which is another reason a provider who knows local floor plans produces a more meaningful result.
How to choose a Lakewood radon testing provider
Verify NRPP or NRSB certification, since Colorado does not license the field. Ask whether they use a continuous radon monitor, how they follow EPA closed-house protocol, and whether the report states the test duration and placement. A credible provider explains both the reading and what it means relative to the 4 pCi/L action level.
For real-estate testing, tamper-resistant continuous monitors are the gold standard. Confirm the provider is independent of any mitigation company if you want an unbiased measurement, and ask for a sample report before booking.
Ask the provider how they handle a borderline result. A reading just under 4 pCi/L still carries risk, and a good professional will explain your options rather than simply declaring the home passed. Ask, too, about retesting cadence: the EPA suggests testing every two years and after any major renovation or foundation work, because changes to a Lakewood home’s structure or ventilation can alter how radon enters. A provider who frames testing as an ongoing practice rather than a one-time box to check is giving you sound guidance.
Finally, keep your results. A documented test, with the date, duration, device type, and measured level, becomes part of your home’s history. If you sell, it satisfies Colorado’s disclosure expectation and reassures buyers. If you mitigate, it establishes the baseline against which the post-mitigation test is judged. A loose memory of a number from years ago does none of that, so file the report with your other home records.
References
- EPA Map of Radon Zones — U.S. Environmental Protection Agency
- Colorado Radon Program and Test Kits — Colorado Department of Public Health and Environment
- Health Risk of Radon — U.S. Environmental Protection Agency
- About Radon — Centers for Disease Control and Prevention
If you are buying or own a home in Lakewood, Green Mountain, or anywhere in Jefferson County’s Zone 1 territory, connect with a vetted radon professional through our contact page.