AIRTIGHT ENVELOPE: Fundamental to any Passive House construction, an airtight envelope eliminates any unintentional gaps between the interior and exterior sides of a building by encompassing it with a continuous membrane or sealed member called an air-barrier. Rigorous detailing is needed to achieve an effective airtight envelope, but the result is a considerable reduction in heating and cooling demands, prevention of mold and rot accumulation, and a remarkably comfortable indoor environment.
