American cities have only recently come of age in the global sense. Therefore, most of our land use regulations have emphasized greenfield development issues over those of a mature city. The next wave of city building is redensification. This thesis argues that modern day, Euclidian zoning needs to be replaced in order to make the case for a sustainable mix of residential diversity, density, and affordability. Conventional zoning relies on simplistic measures to regulate density and shape the form of neighborhoods. Initially used primarily as a way to make the field of planning appear scientific and rational, these measures do not create functionally flexible neighborhoods for the changing needs of the twenty first century. Urban spaces should be thought of as a language, composed of pieces that evolve with cultural norms. Zoning must evolve to reflect current societal values, with an emphasis on environmental issues, while meeting the needs of changing market structures if cities are ever to sustainably house their populous. Zoning's inflexibility towards cultural shifts uses antiquated assumptions to force contemporary city design into a regulatory straight jacket. Using case studies within the city of Los Angeles because of its history in side-by-side integration of single family homes with a range of residential densities and supportive commercial uses, the thesis investigates three primary questions. First, under what zoning ordinances did the Los Angeles neighborhoods evolve and what lessons in functionality can be taken from their design? Second, looking at both conventional zoning and newer, form-based regulatory techniques, how does zoning affect the variety of housing types available? And third, what would a flexible zoning framework, created to support the future development of an evolving regional urbanization process and a changing social demographic, look like?