Estimating the useful life of buildings

Obsolescence is a phenomenon that is widely discussed in the literature, although rarely in relation to buildings. In this paper parallels are drawn between obsolescence,depreciation and discounting in order to develop a new method for predicting the impact of building obsolescence based on measurable context factors. These factors have physical, economic, functional, technological, social, legal and political characteristics. Useful life is defined as discounted physical life, where the rate of discount is determined from predicted future obsolescence. As part of the method, a new tool for determining the physical life of buildings is presented. Using an adaptive reuse paradigm to compare predicted useful life with actual useful life, a large number of case studies is analysed retrospectively. The findings demonstrate that the proposed method is robust and that the concept of discounting physical life using obsolescence as a discount rate is valid.