The design of Don Mills was influenced by Ebenezer Howard’s Garden City, and by the principles of two American town planners, Clarence Stein and Henry Wright, who developed the garden city community of Radburn, New Jersey. Design of the project was entrusted to Macklin Hancock, the son-in-law of Taylor’s executive assistant. Still in his mid-20s, Hancock was a graduate student at Harvard when approached for the job. At Harvard Hancock had studied under a number of the founders of modernism and new town planning including Walter Gropius, William Holford, and Hideo Sasaki. These studies lead Hancock to envision a self-contained community distinguished by consistent design principles and a modernist style. Several names were proposed for the new development, including Eptown after Taylor. It was called Yorktown at its initial unveiling, but the name Don Mills was finally adopted at the suggestion of Hancock.
The design was based on five planning principles, which had not been implemented in Canada before:
- The neighbourhood principle – which broke down the community into four neighbourhood quadrants, all surrounding a regional shopping centre, Don Mills Centre, at the southwest corner of Don Mills and Lawrence. Each quadrant was to contain a school, a church, and a park.
- Separation of pedestrian and vehicle traffic – which was accomplished through the creation of a network of pedestrian paths providing easy access through parks to area schools and the town centre, while roads were designed to slow vehicular traffic through the use of winding roads, T-intersections, and cul-de-sacs.
- Promotion of modernist architecture and the modern aesthetic – Don Mills Development controlled the architectural design, colours, and materials of all buildings in Don Mills. As well, the corporation insisted that builders use company-approved architects who had been educated according to Bauhaus principles, to prevent the project from deteriorating into a typical post-war subdivision of builder’s homes.
- Creation of a greenbelt – linked to a system of neighbourhood parks that would preserve the beauty of the surrounding ravines.
- Integration of industry into the community – which followed Howard’s ideals for the Garden City. Planners felt that it was important for residents to live and work in the same satellite town so that Don Mills would not become a bedroom community. A sizable number of high residential densities—rental townhouses and low-rise apartments—was essential if the town were to attract a cross-section of residents working in local industries.
