Return in basement

Testing location for a real estate transaction home from the 50's. The basement is not finished but could be used as a man cave or entertaining area. There is a return to the furnace more than 10 feet away. Would I be wrong to test in this location instead of on the first floor? My thinking is they could set up a place to entertain and the return is pushing air around the entire house from here. Thus, making this the lowest livable area of the house.

Stephen:

If you think the basement is the "lowest lived in level" then I would say the test location is appropriate. Others might disagree since it is not finished.....

Mike Casey wrote:Stephen:

If you think the basement is the "lowest lived in level" then I would say the test location is appropriate. Others might disagree since it is not finished.....

https://www.epa.gov/sites/production/files/2015-05/documents/hmbuygud.pdf

"Make sure that the test is done in the lowest level of the home that could
be used regularly. This means the lowest level that you are going to use as
living space whether it is finished or unfinished."

I should have included this in the original post. My basis for testing in the basement is that it could be used regularly, whether finished or unfinished. I guess, the testing locations can be subjective depending on the person view of what is livable or could be used regularly.

Thank you, Mike!

Stephen: Exactly! Personally, I would probably choose the basement as you seem to have done.

In Ohio the radon test is supposed to be done in the lowest livable space. An unfinished basement qualifies. Now if the headroom was too low in the basement then no and the test should be done at the next higher floor level.

PA DEP Radon testing protocol states "Radon testing should be in the lowest finishable area"
Very much inline with Mike C & J Troth statements

Thank you all for your comments!