This dissertation will study architectural and urban conservation in San'a as both a global and local phenomenon. The unique architecture of San'a has been the focus of international conservation efforts, which have stimulated local interest and contributed to the formation of a local discourse. Because development has been fairly recent, San'a presents an opportunity to study the ways in which a traditional urban system adapts to change. Traditional builders continue to coexist with a modern building sector, resulting in hybrid forms in both the old city and the new suburbs that defy simple attributions of "tradition" and "modernity." While San'a offers an important local case study, it also provides a framework for the reassessment of western conservation theory and policy which have tended to reify historic districts.