Abstract
Operating cost targets have long been needed by owners and managers of commercial buildings. The only available comprehensive operating costs of a number of office buildings were analysed and budget levels and optimal performance targets were determined, relating to both cost and consumption values. The effects on operating costs of building characteristics such as size, location and quality were examined and a methodology for determining target operating costs developed. Operating budget targets preferred were the lower quartiles of the distributions of the ratio of each cost item to annual income. These levels were selected as difficult but achievable targets independent of such factors as size, location and inflation.