What describes the building envelope?

• A. The shell of the house, controlling flow of heat, air and moisture between inside and outside
• B. The interior partition walls
• C. The HVAC system
• D. The exterior paint and finishes

Answer: (A)

The building envelope is the shell that separates the interior from the exterior and its main job is to control the flow of heat, air, and moisture between inside and outside. It includes exterior walls, roof, floor/ground contact, and foundation, along with the barriers that manage air and vapor movement and protect against weather. Interior partition walls don’t affect the boundary with the outside, the HVAC system is the mechanical system that moves air and regulates temperature, and exterior paint and finishes are surface treatments that provide protection and aesthetics but aren’t the primary controls for heat, air, and moisture transfer.