Design approaches of interest to criminologists today are quite different from the massive urban renewal schemes of the past. Today's approaches, known as defensible space, rely on a group of relatively inexpensive techniques (such as appropriately placed fencing) that define spaces in a manner that discourages criminal activity, for both individual buildings and whole neighborhoods. This document details the principles of defensible space and elaborates on the importance of defensible space in deterring crime and building community. There are sections on applications of the concept in public housing; street patterns and the Broken Windows thesis; defensible space at the neighborhood scale; the potential uses of defensible space for urban neighborhoods and for public housing. Figures, notes