By definition, an “envelope” is an encapsulating covering such as an outer shell or membrane. In simple building terms, it consistsof the roof, the above-grade wall system, and the below-grade wall system. The purpose of the building envelope is to protect the interior from external elements, including moisture, air, and temperature ingress and egress. The definition sounds simple enough, but in reality, because of the thousands of complex products and systems specified and the multiple trades involved, the probability of defects is relatively high…
