A Passive Radon Mitigation System Installed In New Construction

A passive radon mitigation system installed in new construction.

One thing I am seeing more and more in new construction is the installation of a passive radon mitigation system which would only need a fan should a house test positive for radon.

Not all the builders do this.

But when I see it I point it out to the buyers.

This area of Northern Virginia has a medium radon potential.  But there are some spots that are more prone to radon than others.

However, any house can test with a "high" radon result*, and the only way to know is to do a test.

With a passive system, when a house is built a tube is placed through the slab, extending to the dirt below.

Doing this when a house is being built makes it dramatically cheaper to install a radon system in the future, which would have to create a new hole through the slab, and run new PVC tubing that extends from the basement to the outdoors.

Tubing like what you see here makes its way through the house from the basement to exit through the roof.

In the photo on the right the builder actually put a small access location into the roof space where the tubing passes through the roof sheathing.

A receptacle was also placed there to accommodate the electrical needs for an eventual vent fan.

If the house tests positive for radon only a fan would need to be installed, likely in this attic space, and plugged into the receptacle provided.  This would make the installation of a remediation system much cheaper for the homeowner.

Outside the house you can see how the vent tubing passes through the roof to ventilate outdoors.

The system is complete, sans fan.

This buyer would need to wait until he occupies the house, so he can control the opening and closing of windows and doors, and then have a radon test conducted. 

And proceed from there.

My recommendation:  if you live in an area of the country prone to underground radon and want to build a new house, ask the builder if they install a passive system.  If so the aftermath of a positive radon test is much easier to deal with. 

*  This post is not to comment on the controversy of what a "high" radon result is, or whether a high test result is in fact dangerous.