Technical Guide
Passive vs. Active Radon Systems.
The Iowa Builder's Guide to HF2297 Compliance, Installation Standards, and Buyer Protection.
Partner With Our TeamThe Simple Version
A Passive System is just a PVC pipe running from the sub-slab gravel up through the roof. It relies entirely on the natural "stack effect" (warm air rising) to pull radon out. It is required by Iowa law for new builds.
An Active System is that exact same pipe, but with a specialized radon fan installed (usually in the attic). The fan mechanically creates a vacuum under the slab, effectively exhausting the radon gas before it enters the home.
Why It Matters for Your Business
Passive systems rarely reduce radon enough to meet the EPA action level of 4.0 pCi/L in Iowa's high-radon soil. When a buyer tests their new home and finds high radon levels, they look to the builder for answers.
Building the passive stub correctly means activating it later takes just a few hours and minimal cost. Building it incorrectly means tearing into drywall, upsetting homeowners, and delaying closings.
Iowa HF2297 Requirements
Iowa Code requires that all new single-family homes include a passive radon control system. This means laying a minimum 4-inch layer of clean aggregate (gravel) beneath the slab, installing a vapor barrier, sealing all major cracks/joints, and running a 3-inch or 4-inch Schedule 40 PVC pipe from the sub-slab to the roofline.
What Makes a Good Passive Stub?
- Routing the pipe through interior walls to keep the air inside warm (improving the natural stack effect).
- Ensuring an accessible space in the attic for future fan installation, complete with a nearby electrical outlet.
- Terminating the pipe at least 12 inches above the roof, away from any windows or air intakes.
Why Active From the Start?
Many top-tier Iowa builders are choosing to bypass the "wait and see" approach of passive systems, opting to install active systems right from the build phase.
An active system is the only way to guarantee low radon levels for your buyers. Installing the fan and manometer during construction costs a fraction of a post-close retrofit, serves as a major selling point for health-conscious buyers, and completely eliminates the risk of closing delays due to failed radon tests.
The All Midwest Radon Promise
When we activate a system on your build, we guarantee the final levels will test below 2.7 pCi/L.
Working With All Midwest Radon
Blueprint Review
We consult with your architects and project managers to ensure the passive system routing is optimized for both aesthetics and future active conversions.
Site Inspections
Our certified specialists perform pre-pour and framing inspections to guarantee HF2297 compliance, ensuring the vapor barrier and aggregate meet state codes.
Turnkey Activation
We provide seamless system activations before closing, installing premium Festa AMG fans and providing clearance testing for immediate peace of mind.
Build with confidence.
Let us handle the radon technicalities so you can focus on building great homes.