Air leakage testing measures how much air escapes from a building's envelope, which includes walls, roofs, and floors. This testing helps identify areas where air leaks occur, allowing for improvements in energy efficiency and indoor comfort. Common methods include the Blower Door Test, which uses a fan to create a pressure difference, and Infrared Thermography, which detects temperature variations. By pinpointing leaks, property owners can reduce heating and cooling costs, enhance indoor air quality, and minimize moisture problems. Regular air leakage testing is essential for maintaining the integrity of a building and ensuring compliance with energy codes and standards.