This thesis was a combination of theoretical work and a design project. The first, presented here, sets forth my ideas on proper implementation of historic preservation as a planning tool. It includes an outline of my preservation philosophy, and a set of design guidelines developed for Maskeret Moshe - a 19th century neighborhood in Jerusalem. The second part, which was submitted separately, consisted of a design for a new day care center in Maskeret Moshe. The design built upon and implemented the theoretical part of my thesis.