Book excerpt: Public facilities are valuable assets that can provide decades of high quality of service if they are effectively utilized. Despite effective planning, design, and management, sometimes users or owners change and have requirements different from those that the facility was initially intended to fulfill. In addition, the technologies sometimes change, making facilities obsolete before they have worn out or otherwise failed. This book explores the meaning of obsolescence as the term applies to buildings. It discusses the functional, economic, technological, social, legal, political, and cultural factors that can influence when obsolescence will occur and considers what design professional and building owners and users can do to delay and minimize the costs of obsolescence. The analyses apply to all buildings, but public facilities are given added attention because of their special management problems.