Air Tight Modular Home Construction
The air tight layer (ATL) is  one of the most important components of Passive House building and is probably the most  difficult to achieve.  Air leakage  through a building assembly not only results in energy loss, but more importantly  it can compromise the durability of a structure by trapping waters vapors in  any assembly. Mitigating air leakage is  the most cost effective measure of reducing energy loss and is the “secret  sauce” of any Passive House building. Passive House Certification requires buildings to  achieve air leakage no greater than .6 ACH at 50 pascals of pressure!