When it comes to defining the spatial layout within buildings a common theme today is achieving a developers dream of 100% net internal area (NIA) to gross internal area (GIA). Obviously this ratio is impossible but the 80% mark is usually the aim. In today's climate the driver is money. In the past we have seen the delineation of 'served' (the main element, such as a trading floor, dwelling or theatre) and 'servant' (the ancillary elements, such as circulation and services) space being associated with flexibility, future refurbishment, security, public vs private, and even social class.

Below are three examples from different periods that show 'served and servant space'. These ideas are not new.

Orfold Castle 1173 by Henry II,

Orfold Castle 1173 by Henry II,

Richards Building 1965 by Louis Kahn,

Richards Building 1965 by Louis Kahn,

Lloyds Building 1986 by Richard Rogers.

Lloyds Building 1986 by Richard Rogers.