What term describes the shell of the house that controls the transfer of heat, air, and moisture between inside and outside?

• A. Door and window fixtures
• B. Building envelope
• C. Interior finishes
• D. HVAC system

Answer: (B)

The main idea is the boundary between indoors and outdoors that controls how heat, air, and moisture move in and out of the house. This boundary is the building envelope, which includes the walls, roof, foundation, and openings like doors and windows, plus the insulation and air/moisture barriers that limit transfers. Its purpose is to keep warmth in when it’s cold, keep heat out when it’s hot, and manage moisture to prevent condensation, dampness, and mold, while protecting the structure. Door and window fixtures are part of the building boundary, but they’re only components; interior finishes stay inside and don’t govern the transfer between inside and outside; the HVAC system handles conditioning but is separate from the boundary.