Healthy homes
Radon and a new Eastside home: what to decide before construction
Radon is invisible and odorless. The easiest time to make a house ready for mitigation is while it is being built, before the slab, walls, and mechanical systems are finished.
Reviewed against official sources · August 2026Start with testing and local information
Radon levels can vary from house to house. A map can show regional patterns, but it cannot tell you the level in a specific finished home.
Washington’s Department of Health explains testing, health risks, and radon-resistant construction on its radon information page.
Make future mitigation easy
- Discuss a gas-permeable layer and sealed slab penetrations.
- Plan a vent pipe route from below the slab to above the roof.
- Provide an accessible location and electrical connection for a future fan.
- Test after the home is enclosed and occupied, then mitigate if needed.
Coordinate it with the plans
Ask the architect and mechanical team to show the intended route and details. A small amount of planning now can avoid opening walls later.
Action plan
Make the home radon-ready
- 1
Review Washington’s radon map for context, but do not use it as a substitute for testing the finished house.
- 2
Ask the architect to show the below-slab gas layer, sealed penetrations, vent route, roof termination, fan location, and nearby power source.
- 3
Keep the vent route away from windows and coordinate it with plumbing, structure, and mechanical shafts.
- 4
Test the lowest regularly occupied level after construction under the kit or professional’s instructions.
- 5
If results are elevated, activate or improve mitigation and retest to confirm the result.
Official resources