Air sealing a home is generally considered the most cost-effective way to reduce heating and cooling energy use. It also improves comfort and indoor air quality. Achieving a high level of air tightness requires more than just filling visible holes. High-performance homes have a continuous air barrier. The key word here is continuous. The secret to continuity is to identify large sheets of material that already exist and bridge the gaps – or joints – between them in order to completely seal the structural sheathing. Several good methods exist to install a continuous air barrier. Some are “homegrown” solutions  based on skilled use of materials in the field, such as air-tight drywall (ADA) and adhesive attachment (gluing) of the sheathing. Others, like Siga membranes and ZIP System, are proprietary and therefore slightly more expensive. We’ll discuss these and other approaches in more detail.