the modular system of design that allowed for interchangeable components to be added or subtracted. The principle of modules allowed units to be configured in different ways; Strothoff utilized three interchangeable modules: the window, entrance, and garage. Generally, most dwellings conformed to three-module configurations that allowed for the greatest variation in the street; however two- and four-module houses were not uncommon. From the streetscape, this system provided both unity and diversity: each house could conform to various configurations without essentially altering the overall design character of the neighborhood. This ensured that not only the design elements were regulated, but also the overall appearance of the streets. The elevation and natural topography of Westwood Highlands was used to its advantage. In contrast to the rest of San Francisco, which was dominated by the grid organization, Westwood Highlands adopted the system of curvilinear streets, which naturally fitted the steep environment. Corner lots had a dual purpose in both complementing the curvilinear streets and binding the community neighborhood. The corner block provided a private-public relationship with the intersection. In the planning of Westwood Highlands, corner lots were designed to ensure they faced the street intersection on the diagonal. It was used as a systematic means of ‘softening ‘ the relationship between the public streets and the private nature of the houses suggesting a more open neighborhood community. Another consideration in the planning of Westwood Highlands was the hierarchy of streets and lots. In previous subdevelopments in surrounding areas such as Westwood Park and Saint Francis Wood, lots were sold as empty parcels of land in which private owners could develop as they wished. In Westwood Highlands, lots were marketed and sold as a complete package, with a predetermined existing designed house. Again, the topography was influential in determining the value of each lot. Dwellings on steeper gradients generally had smaller lots (and subsequently smaller houses) with views of the city, while larger lots had more affordable houses and were generally located on the outer-eastern boundaries of the development. Influences While Westwood Highlands was partly an instinctive response to the 1906 earthquake disaster, it was also a reaction to the increasing population trends of the time. This private development movement had many influences on town planning, and Westwood Highlands established some important influences on the private development planning in the United States. Firstly, in relation to planning and practice, Baldwin and Howell, as mentioned