A Comprehensive Development Area (CDA) was a designation under the Town and Country Planning Act (1947) . This allowed a local authority to acquire property in the designated area, using powers of compulsory purchase in order to replan and develop urban areas suffering from war damage or urban blight.

Surveys and feasibility studies were required for a CDA to be considered and approved by the relevant Government Minister. In Scotland, this was the Secretary of State for Scotland. The University of Edinburgh had two CDAs planned. Unusually these were instigated by the University, rather than the local authority, and planned by Percy Johnson-Marshall & Associates. The University/Nicolson Street CDA (1962) comprised a large area including that already earmarked for University development. The latter was to be linked to a new commercial zone and a residential area to the east and required collaboration between the University, the Local Authority and private developers. The scheme, however, stagnated and was never approved by the Secretary of State, becoming officially defunct in 1975, with Local Government Reorganisation and the publication of the South Side Local Plan, (formerly intended as the South Side District Plan).

The Mound/Lawnmarket CDA was another proposal by Johnson-Marshall that never achieved statutory status. This area consisted of about 8 acres of densely built-up, and fairly ancient property in the Old Town surrounding the headquarters of the University's Faculty of Divinity at New College. The scheme started with the need for renovation of New College and the dire state of some historic buildings adjacent to it (1961). A CDA was proposed in 1967 to enable expansion of the academic buildings and conversion of several old tenements for student accommodation. However, the scheme was scaled down, although Mylne's Court was successfully rehabilitated for residencies and New College restored, by 1970. Ultimately, other properties were found to be not viable for conversion and the CDA proposal was advanced no further. The University operated from a variety of sites: the Central Area, including George Square and Old College; King's Buildings, the location of the Faculties of Science and Engineering; Pollock Halls, the student residences; The Mound/Lawnmarket, including New College; High School Yards, where many historic buildings were converted for University use, between 1905 and 1965. There were also departments operating from individual sites around the city.