On 1 January 1949 the boundaries of the City of Sydney expanded to take in the neighbouring municipal councils of Glebe, Darlington, Newtown, Erskineville, Alexandria, Waterloo, Redfern and Paddington. This expansion took place in accordance with provisions in the Local Government (Areas) Act 1948. To effectively manage the enlarged area, and also to come to grips with new town planning responsibilities given to local government after 1945, the City of Sydney embarked on a project to produce a detailed map of the new local government area. The City commissioned an aerial photogrammetric survey, which was flown on 15 December 1949 at 4800 feet by Adastra Photography. Using the aerial photographs as a basis, the staff of the City Building Surveyor’s Department prepared a set of map detail sheets (see the Building Surveyor’s Detail Sheets, 1949-1972). The aerial survey comprised 163 images, taken in several runs across the City and adjacent areas, with a high degree of overlap between adjacent images. Five of the original images have not survived, but the overlap means that all areas are covered.