> Neither of these are terribly "air tight"
Newer homes in the US often have a hole in the basement explicitly to make them not airtight. This is presumably to avoid CO2 buildup.
Newer homes in the US often have a hole in the basement explicitly to make them not airtight. This is presumably to avoid CO2 buildup.
Below about 3.0ACH50, you generally explore active ventilation, which is why 3ACH50 is code, since it doesn't require that extra machinery.