In structural engineering, a pre-engineered building (PEB) is designed by a manufacturer to be fabricated using a pre-determined inventory of raw materials and manufacturing methods that can efficiently satisfy a wide range of structural and aesthetic design requirements. Within some geographic industry sectors, these buildings are also called Pre-Engineered Metal Buildings (PEMB) or, as is becoming increasingly common due to the reduced amount of pre-engineering involved in custom computer-aided designs, simply, Engineered Metal Buildings (EMB). Merits of pre-engineering building

Historically, the primary framing structure of a pre-engineered building is an assembly of “I” shaped members, often referred to as “I” beams. In pre-engineered buildings, the “I” beams used are usually formed by welding together steel plates to form the “I” section. The “I” beams are then field-assembled (e.g. bolted connections) to form the entire frame of the pre-engineered building. Some manufacturers taper the framing members (varying in web depth) according to the local loading effects. Larger plate dimensions are used in areas of higher load effects.