Structural Assembly

The simpler method is to describe the U-factor of the construction assembly which can account for thermal bridging and other factors. However, with this method, the time delay of heat transfer through the construction assembly is not accounted for. Generally, with the U-factor method, heat transfer is assumed to occur instantly. The more complex method is to describe the construction assembly as a series of layers, each layer representing a material. With this method, heat transfer is delayed in accord with the thermal mass and other properties of the assembly.

Air Control Layer

We’ve invested the better part of 20 years to doing a deep dive into understanding what works and what doesn’t when it comes to achieving predictable air sealing on buildings that are erected outdoors … where surfaces are sometimes wet, sometimes dirty and most times where elements of the building-wide air barrier are installed by different subcontractors - with different levels of care and expertise - at different times during the build process. The purpose of the air barrier is to limit the amount of air movement through a building’s shell. A tightness level of 3 air changes per hour or less while a blower door is operating at 50 pascals must be achieved. Most new homes, which use either poly or spray foam as the air barrier, average 2 – 2.5 ACH50.

Thermal Control Layer

The components that are designed and installed in an assembly to control the transfer of thermal energy (heat). It's what keeps our homes and buildings warm in the winter and cool in the summer. Continuous adhesive lamination avoids potential for thermal bridging which compromises thermal performance. Build SMART uses a Red List Free lamination adhesive based on Silyl terminate poly ether. Most Sips producers use moisture cure polyurethane adhesives catalyzed with toxic isocyanates. Thermal performance effects heating and cooling costs, comfort, and can provide or reduce moisture drying potential within building assemblies.

Water Control Layer

The layer in an enclosure assembly that controls the passage of liquid water even after long or continuous exposure to moisture. More formally, the water control layer is the continuous layer (comprised of one of several materials and formed into planes to form a three dimensional boundary) that is designed, installed, or acts to form the rainwater boundary.

Climate-Specific Design