Building Envelope

Building Envelope

The building envelope is the separation between the interior and exterior environment of a building, consisting of the roof, doors, windows, foundation, and walls. Think of it as a building package because it contains more than just the roof. “You’ll often hear...
Blower Door Tests

Blower Door Tests

Blower door tests measure the air tightness of a building and determine the home’s air infiltration rate. How it works: A certified auditor mounts a powerful fan onto an exterior door. The fan pulls air out of the house, lowering the air pressure inside. The higher...


buckwheat: a plant cultivated for its triangular grains, which are protected by a hull. This crop is generally grown without herbicides and pesticides.

Brominated Flame Retardants

brominated flame retardants: chemicals added to plastics, textiles, furniture foam and padding, and other products to prevent them from catching fire. BFRs, as they are also known, are long-lived poisons that build up in fat. In animal studies, they have been linked...

British thermal unit (Btu)

British thermal unit (Btu): the amount of heat required to raise the temperature of 1 pound of liquid 1 ºF. A single gallon of propane contains 91,600 Btu. A cord of wood contains 12 million to 33 million Btu, depending on the type of wood.

bisphenol-a (BPA)

bisphenol-a (BPA): an industrial chemical best known for making polycarbonate plastic and epoxy resins. Found in hard plastic water bottles and baby bottles, in coatings inside metal food and drink cans, and in paints, adhesives, dental sealants, computers, and other...