MachineMachine /stream

The notion of SHEARING LAYERS is one of the centerpieces of Brand's How Buildings Learn [Brand 1994]. Brand, in turn synthesized his ideas from a variety of sources, including British designer Frank Duffy, and ecologist R. V. O'Neill. Brand, Page 13

Brand quotes Duffy as saying: "Our basic argument is that there isn't any such thing as a building. A building properly conceived is several layers of longevity of built components".

Brand distilled Duffy's proposed layers into these six: Site, Structure, Skin, Services, Space Plan, and Stuff. Site is geographical setting. Structure is the load bearing elements, such as the foundation and skeleton. Skin is the exterior surface, such as siding and windows. Services are the circulatory and nervous systems of a building, such as its heating plant, wiring, and plumbing. The Space Plan includes walls, flooring, and ceilings. Stuff includes lamps, chairs, appliances, bulletin boards, and paintings.

These layers change at different rates. Site,