The buildings around us form a part of everyone’s environment and their impact can be positive or negative. Many factors contribute to their external appearance, some of them practical, others cultural or geographic, yet much of the discussion tends to focus primarily on the aesthetics of the façade. In this chapter we look at some of the many issues involved in the design of exteriors and at some of the questions that we need to consider in order to understand them. The external form may be determined at the outset by the function of the building, the shape of the plot of land, or by a preconceived shape such as a cube, rotunda or even a car grille. Stanley Tigerman* Associates designed the Self Park Garage at 60 East Lake Street, Chicago, 1986, to communicate its function literally. The metal clad exterior of this building has skylights in the form of headlights and two black vinyl canopies that look like wheel treads; there are bumpers/fenders, and the car body has a turquoise enamel finish like a Chevrolet. The licence plate reads SELF PARK and there is car parking for 200 vehicles above two floors of retail space. Other buildings are designed from the inside out, so the exterior forms reflect the location, size and shape of the internal spaces.