Conservation subdivision design offers an environmentally superior alternative to traditional large-lot, low-density subdivision development but remains far less prevalent. Moreover, when it is implemented, commonly identified goals of protection of lands with conservation value, creation of a regional network of open spaces, and contribution to improved water quality are often not reached. This paper investigates how local land use regulations impact conservation subdivision implementation; specifically whether regulations pose barriers to the development and environmental success of conservation subdivisions. The empirical analysis is based on a review of the zoning ordinances of 19 Waukesha County, WI, U.S.A. communities where 54 conservation subdivisions were built between 1990 and 2005. The ordinance review was supplemented with a review of permitting documents for 22 subdivisions and interviews with 16 developers. The analysis finds that conservation outcomes in a subdivision were seldom significantly different based on the presence and specificity of land use regulations and guidelines. In addition, the study identifies the permitting process and its most important tool, the zoning ordinance, as barriers to the successful implementation of conservation subdivision design. An important implication of this research is that unless conservation subdivisions are permitted by right or encouraged with incentives, rigorous guidelines for natural resource protection are provided, and the design is championed by key decision makers, conservation subdivision design is likely going to remain the less-popular development pattern at the urban fringe, and its environmental goals will continue to be compromised.