Radon-Resistant New Construction
Related Resources
"Building Radon Out: A Step-by-Step Guide on How to Build Radon-Resistant Homes" (PDF, 84 pp, 8.3MB, About PDF)
Radon Resistant Construction Architectural Drawings (Available as a 522K executable file for use with CAD programs and a PDF Version (PDF, 4 pp, 962KB, About PDF)
- Why Should You Build Homes with Radon-Resistant Techniques?
- What are Radon-resistant construction techniques?
- How Many Homes Are Built With Radon-Reducing Features?
- ASTM 1465: Standard Practice for Radon Control Options for the Design and Construction of New Low-Rise Residential Buildings
- If you have further questions about Radon
Why Should You Build Homes with Radon-Resistant Techniques?
They Make Homes Safer from Radon
- These construction techniques help block radon from entering the home. The occupants will benefit from lower radon levels in their new home.
- They are easy to upgrade when there is a need to increase the radon reduction.
- If high radon levels are found, the techniques allow for easy and inexpensive installation of a fan for increased radon reduction in the home. Every new home should
be tested for radon by the homeowner after occupancy.
- They are cost-effective for home buyers
- It is more cost-effective to include radon-resistant techniques while building a home, rather than installing a radon reduction system in an existing home.
- For example:
- The cost to a builder of including radon reducing features in a new home during construction can vary widely. Many builders routinely include these features in some of their homes. The cost to the builder of including these features is typically less than the cost to mitigate the home after construction.
- The cost to a builder of including radon reducing features in a new home during construction can vary widely. Many builders routinely include these features in some of their homes. The cost to the builder of including these features is typically less than the cost to mitigate the home after construction.
- Some construction companies successfully use this as a marketing advantage.
- They may improve the home's energy-efficiency
- Radon-resistant construction techniques are consistent with state-of-the-art energy-efficient construction. When using these techniques, follow the Model Energy Code (or other applicable energy codes) for weatherization, which will result in energy savings and lower utility bills.
What are Radon-resistant construction techniques?
The techniques may vary for different foundations and site requirements, but the basic elements are:
- Gas Permeable Layer
This layer is placed beneath the slab or flooring system to allow the soil gas to move freely underneath the house. In many cases, the material used is a 4-inch layer of clean gravel.
- Plastic Sheeting
Plastic sheeting is placed on top of the gas permeable layer and under the slab to help prevent the soil gas from entering the home. In crawlspaces, the sheeting is placed over the crawlspace floor.
- Sealing and Caulking
All openings in the concrete foundation floor are sealed to reduce soil gas entry into the home.
- Vent Pipe
A 3- or 4-inch gas-tight or PVC pipe (commonly used for plumbing) runs from the gas permeable layer through the house to the roof to safely vent radon and other soil gases above the house.
- Junction Box
An electrical junction box is installed in case an electric venting fan is needed later.
How Many Homes Are Built With Radon-Reducing Features?
Based on an annual home builder survey conducted by the National Association of Home Builders (NAHB) Research Center:
- 5.8% of approximately 1,124,000 single-family detached homes built during 2001 incorporated radon-reducing features, which translates to about 65,000
homes. This brings the cumulative total of single-family detached homes built with radon-reducing features since 1990 to over one million homes.
- 11.7% of approximately 255,000 single-family detached homes built in Zone 1 (homes with high radon potential) during 2001 incorporated radon-reducing features,
which translates to nearly 30,000 homes. This brings the cumulative total of single-family detached homes built in Zone 1 with radon-reducing features since 1990 to over 600,000 thousand.*
* These results exclude homes built on pier-style foundations.
This ASTM standard covers the design and construction of two radon control options for use in new low-rise residential buildings. This is the latest version of ASTM’s standard, and EPA recommends it as the approach for RRNC. EPA, through agreement with ASTM, can provide one free copy of the standard. If you would like to order a copy, visit our publications page.
Radon control methods are also found in other, older, documents:
- Appendix F of the International Code Council’s (ICC) International Residential code (IRC); www.internationalcodes.net
- National Fire Protection Association (NFPA 5000) residential code; www.nfpa.org
- A 1994 publication from EPA, “Model Standards and Techniques for Control of Radon in New Residential Buildings (Model Standards, EPA 402-R-94-009, March 1994)”. Since we recommend ASTM E 1465-07a for RRNC, we no longer update or publish our old document.
- Elements of the Model Standards were incorporated into the One and Two Family Dwelling Code, Conference of American Building Organizations (CABO, 1995), and in CABO’s successor International One and Two Family Code (1998).
If you have further questions about Radon, please call your State Radon Contact (just click on your state) or the National Radon Information Line at:
1-800-SOS-RADON
[1 (800) 767-7236]