If you are a designer or builder who wants to achieve a high-performing, durable Passive House building, you need to understand control layers. Control layers are materials and systems of materials that are specially designed, selected, and detailed to control water, vapour, and air. They are placed throughout the building, from the roof, walls, and floor to the below-grade enclosure assemblies, details, and interfaces. They consist of membranes and other materials typically described as air barriers, vapour barriers, and water-resistive barriers, or collectively as critical barriers.

The design, selection, and placement of control layers can be challenging. Given the highly insulated nature of passive house buildings, even small mistakes in water and air control can create problems. Simply adding insulation to traditional wall and roof assemblies is risky, so air and vapour control practices must be adjusted to consider the assembly layers and details. Therefore, to design and construct effective passive house buildings, designers and builders must understand the building science behind control layers.

Session 2 will take a deeper dive into rainwater control and detailing as well covering vapour control for walls.