In 1953, Stephenson was commissioned by the state government of Western Australia to produce a plan for the metropolitan area of Perth and Fremantle. The resulting 1955 Plan for the Metropolitan Region, Perth and Fremantle was co-authored with Alistair Hepburn, and is commonly known as the “Stephenson–Hepburn Report”. It included an atlas of maps which laid down a broad pattern of future land uses including highways and open space, and catered for significant additional population growth. The report formed the basis for the 1963 Metropolitan Region Scheme for Perth and Fremantle, a legal instrument for regulating land-use and development in the urban area. It remained the overarching strategic plan for the development of Perth until it was succeeded by the Corridor Plan for Perth in 1970.