Radon-ready new construction

"It's a brand-new house" is not a radon strategy

A 2024 build in Timnath sits on the same decomposed-granite soils as a 1955 ranch near downtown Loveland — and often tests just as high or higher. Modern homes are sealed tighter, which conserves energy and also concentrates whatever seeps up through the foundation. Builders here increasingly include passive radon rough-ins (in many Colorado jurisdictions it's required by code for new residential construction), but a passive system is a head start, not a guarantee. The honest sequence for every new home in Larimer County: move in, test, and if it's high, activate. Each step is small; skipping the test is the only real mistake.

What a proper rough-in includes

If you're building — custom home, spec, or an addition — this is the checklist that makes radon control nearly free for the life of the house:

• 4 inches of clean gravel under the slab so gas moves laterally to a collection point instead of pooling.
• Perforated collection loop or tee set in the gravel, stubbed through the slab.
• Sealed polyethylene vapor barrier over the gravel before the pour — laps taped, penetrations sealed. (On our expansive clays this doubles as good moisture practice.)
• A 3–4" vent stack through conditioned space — inside a framed chase, warm from slab to roof. Warm stack = natural draft = the passive system actually does something. Exterior retrofit runs never draft as well.
• A junction box in the attic next to the stack, so activating later means hanging a fan, not hiring an electrician.
• Sealed sump lid and caulked slab joints — details that cost dollars during construction and hundreds after carpet and trim.

Activation: the 90-minute upgrade

When a radon-ready home tests high — and on Front Range soils, many do — the fix is the easiest one in the industry: an inline radon fan mounted on the existing attic stack, wired to the waiting box, then a verification test. No coring, no visible pipe, no drywall work. If you just closed on a new build in Johnstown or east Loveland and your inspection test came back at 6, this is almost certainly your situation, and it's a same-week fix.

For builders and GCs

We work with Northern Colorado builders on rough-in specs that pass inspection and actually perform — collection layout sized to the footprint, stack routing that keeps warm air moving, labeling per ANSI-AARST new-construction standards, and post-occupancy testing for your buyers. A radon callback is a cheap thing to never have: the rough-in costs a few hundred dollars per unit at slab stage, and "every home tested, radon-ready guaranteed" is a line your sales office gets to use in the most radon-aware buyer market in the country.

Remodels: the moment to think about it

Finishing a basement in one of Loveland's 80s and 90s neighborhoods is the classic case: you're about to turn the highest-radon floor of the house into bedrooms and a family room. Test before the drywall goes up. If the house needs a system, installing it during the remodel means the pipe hides inside new framing and the suction point tucks into the utility room — invisible, quieter, and cheaper than retrofitting around finished space a year later. Pouring a slab for a garage or addition? Stub in a collection point while the ground is open; it costs almost nothing.

Building, buying new, or opening up a basement? Tell us about the project or call (970) 536-1157 and we'll tell you exactly what the house needs — and what it doesn't.