Have to say that i see 90% of the houses without actual ventilation. Sure, there is a report by some 3rd party somewhere saying it is in the house, when in reality it was never verified. Years back our towns adoped energy star v2. Now that that program has been sunseted years ago most require a HERS rated house. For us at least this has simplified many things, as measuring ventilation is a minimum rated feature. The difficult part is educating us ceos. There has been many years without any oversight, and decay has effected many. Just yesterday i did a final and found the bathroom exhaust fan exhausting into the attic, zero ventilation in the house, closed cell foam against (and on) a singlewall boiler flue. Zero combustion testing, with a certificate saying that house passed NYS code from a 3rd party....