(pronounced BIHL-ding AHN-veh-lohp)

Is this perhaps stationery made of stucco? Uh… no. The building envelope is pretty much what it sounds like – that which surrounds (or envelopes) the building. Just like the skin on a person is a human envelope and a shell on an egg is a chicken envelope (OK, we’re stretching it here), the exterior of a structure is a building envelope. As a whole, it acts as insulation, separating its inhabitants from the elements. Building envelope components are the foundation, roof, exterior walls, doors, and windows. These integrated pieces all work together to keep out wind, moisture, dust, and harsh temperatures. If the envelope is not well insulated, then it will hemorrhage conditioned air, as is evident through infrared thermography images. Not only is this expensive for the structure’s owners, but it can be detrimental to the building’s systems and the structure itself, as well as uncomfortable to the building’s users.

One last thing: In relationship to zoning and urban planning issues, you may also see this term used to describe the maximum space – three-dimensional: width, depth, and height – on a piece of property that a structure can occupy.