This paper describes the origins, operation and design of the 2007 Floor Space & Employment Census and the complimentary design of a quasi 3-dimesional GIS model of the internal workings and built form of the City, and ancillary applications.

In the wake of globalising economic trends and technological change, as well as prospective environmental change, the central business districts of metropolitan cities are going through a period of massive economic change. This, in turn, dramatically affects the structure of metropolitan areas. This change reflects itself in the nature and type of businesses locating there, and the amount of built form change. To aid city policy-making to formulate appropriate decisions, the City of Sydney Council has been undertaking a full census of all floor space and employment in its jurisdiction every five years for the last three decades.

This census is the first of its type to be directly incorporated into a GIS, allowing for more extensive spatial analysis of data and trends than previous data sets. Data from previous censuses have been held in conventional non-spatial databases.

For the 2007 Census, the Council determined to take a quantum leap and collect the information as part of a full GIS database to enable analysis and presentation of the records in a 3-D model. Data was collected for all buildings, establishments and spaces within the City of Sydney local government area (LGA). For each of the 27,000 buildings in the City of Sydney area, data is held for all establishments (name and industry of business) within the buildings, the uses of internal and external floor space, and the number of employees within each space. Additionally, various measures of capacity have been recorded for different types of space uses. The data can then be aggregated from the smallest level (5m²) up to building, block, precinct and LGA level.

The paper will outline the development of the database within the GIS, including design for input, retention and editing of the data. The database was built within Council's existing GIS platform ArcGIS (ESRI). Data entry forms were created to assist in the input of 625,000 space records, 19,500 business establishments and 27,000 buildings.

Finally, the paper will outline the use of the data to undertake cluster analyses of the retail and cultural sectors of the City of Sydney economy, and their spatial relationship to the local residential market. Further projects undertaken using the data include;

· Capacity Studies - looking at the development potential of certain areas under existing planning laws;
· Business Precinct Studies - business mix and employment concentrations of precinct areas for business planning;
· Housing Stock Analysis - complete count of quantity, type and age of residential building stock.

The 2007 Floor Space and Employment Census is a platform for building scenarios and simulating future outcomes in response to strategic challenges facing Sydney in the 21st century. The Census will also provide the information for much of the base case analysis for the City of Sydney's 2030 Vision.