Where do air leaks most commonly occur in construction?

Air leaks most commonly occur at joints, intersections, and penetrations in construction because these areas are where different materials or structural components come together, creating potential gaps through which air can flow. These points of connection can be beams meeting walls, where plumbing or electrical systems penetrate walls, or the joints where different types of siding meet.

Effective air sealing is crucial at these locations because they present opportunities for uncontrolled air movement, leading to energy loss, moisture intrusion, and potential comfort issues within the building. Addressing air leaks at these points is a key focus in the design and construction process to enhance energy efficiency and indoor air quality.

Other choices may suggest specific locations, but they do not encompass the broader range of areas where air leakage can occur. For example, air movement around windows and doors, while significant, is just a part of the overall potential leakage points. Similarly, leaks at the roofline and in the foundation, while important, do not account for the multiple seams and connections that exist within the wall systems themselves.