We tested our current house and it had virtually no radon - it's a slab on grade. So if we build another slab on grade 5 miles away, do we need to remediate?
Based on Crow Wing County's radon level, the answer is yes.
Here's a great document on radon and how to remediate in new construction:
We don't know of anyone that has installed radon remediation in Minnesota. It's not part of the building code, it's not tested. Yet, radon attributed deaths are half that of those killed in auto accidents - and much higher than fires or drownings.
But what about radon remediation in passive houses? Does the super-sealed house prevent radon? Apparently not. Here's an experience of one owner of a passive house that had radon issues:
http://connecticutpassivehouse.blogspot.com/2014/05/radon-and-passive-house.html
So, where does the stack go? If you put in a passive stack outside the envelope, there won't be enough heat to draw the air up the stack. If it's in the building envelope, then heat is drawn out the vent pipe. Do we put the stack in and seal the top until we have tested the house for radon and determine if the remediation was needed?
http://connecticutpassivehouse.blogspot.com/2014/05/radon-and-passive-house.html
So, where does the stack go? If you put in a passive stack outside the envelope, there won't be enough heat to draw the air up the stack. If it's in the building envelope, then heat is drawn out the vent pipe. Do we put the stack in and seal the top until we have tested the house for radon and determine if the remediation was needed?