The material durability (physical life) of a building is often different from what it actually lasts (economic life). For example, a building made of modern materials, such as concrete and metal, can stand at least for fifty to sixty years. However, a common observation in Taipei is that the majority of buildings are knocked down, often for redevelopment, far ahead of their physical end. The difference between physical and economic life shall have noticeable impact on urban regeneration, building depreciation, or building values. Despite the policy significance, the economic life of buildings is still under-researched. We analyze a data set of over 10,000 buildings in Taipei City demolished between year 2007 and 2009, with information on age, material, location and floor areas and so on. It is hoped through this analysis to uncover the determinants of the economic life of buildings, and to explore their implication on urban development and land use.