Definition: Air leakage in a home occurs when outside air enters and conditioned air leaves your house uncontrollably through cracks and openings. It is unwise to rely on air leakage for ventilation. During cold or windy weather, too much air may enter the house. When it's warmer and less windy, not enough air may enter, which can result in poor indoor air quality. Air leakage also contributes to moisture problems that can negatively affect occupants' health and the structure's durability. An added benefit is that sealing cracks and openings reduces drafts and cold spots, improving comfort. Before air sealing, it is wise to perform an energy audit to detect air leaks and assess ventilation needs for indoor air quality. Then, air sealing can be implemented such as caulking and weatherstripping.