Detailed knowledge of building parameters in the context of settlements can provide essential impulses for resource-saving, land-efficient spatial development. Knowledge of the building stock in terms of use and dimensions is an initial basis for quantifying land potential for internal development or for locating areas with particularly high energy-saving potential. The aim of the methodology developed in Zentrum Alpines Bauen is to develop a reliable database for characterizing the existing building stock. The gained knowledge should be made available to the planning policy and administration in order to be able to implement it in spatial development concepts. A GIS-based methodology was developed, which enables an automated derivation of indicators regarding the geometry of buildings that are essential for spatial planning. The procedure consists of four steps: (1) derivation of building area from roof area; (2) calculation of gable height and volume; (3) estimation of number of stories and gross floor area; (4) calculation of building envelope.