Where does air leakage in buildings occur most?

Where does air leakage in buildings occur most?

• A. Around doors and windows
• B. On the roof
• C. In the middle of walls
• D. At the floor

Answer: (A)

Air leaks happen most where the building envelope is interrupted by openings and joints, allowing air to pass through small gaps. Doors and windows are the typical weak points because they create many seams around frames, and weatherstripping or caulking can wear or loosen over time. Even when closed, gaps around these openings let heated indoor air escape and outside air enter, especially with pressure differences from wind and temperature. That combination makes these edge areas the main routes for leakage. The roof isn’t usually a primary air-leakage path; it’s where water intrusion can occur and where attic ventilation components exist, but it doesn’t provide as many continuous leakage paths as the frame openings around doors and windows. The middle of walls and the floor have fewer persistent gaps compared to the frame openings, so they contribute less to overall air leakage.

Air leaks happen most where the building envelope is interrupted by openings and joints, allowing air to pass through small gaps. Doors and windows are the typical weak points because they create many seams around frames, and weatherstripping or caulking can wear or loosen over time. Even when closed, gaps around these openings let heated indoor air escape and outside air enter, especially with pressure differences from wind and temperature. That combination makes these edge areas the main routes for leakage.

The roof isn’t usually a primary air-leakage path; it’s where water intrusion can occur and where attic ventilation components exist, but it doesn’t provide as many continuous leakage paths as the frame openings around doors and windows. The middle of walls and the floor have fewer persistent gaps compared to the frame openings, so they contribute less to overall air leakage.