Systematic statement of a body of rules that govern and constrain the design, construction, alteration, and repair of buildings. Such codes are based on requirements for the safety, health, and quality of life of building users and neighbors, and vary from city to city. Model codes developed by states, professional societies, and trade associations—including the BOCA (Building Officials and Code Administrators) coda, National Building Code, Uniform Building Code, and Standard Building Code—are typically adopted by local communities, with amendments. New York City's code is the oldest (1916) and, because of the city's population density and such concerns as fire prevention, adequate light, and ventilation, the most stringent.