The design and implementation of a computer-based Building Design Support Environment (BDSE) is described. The structure and operation of the BDSE is derived from a detailed analysis of the building design process, based on three basic iterative and interactive activities, i.e., the formulation of design criteria, the generation of potential solutions, and their evaluation. These three activities are fundamentally different with respect to the type of the required knowledge and the degree to which they can be specified and delegated to a computer. As a result, a variety of design tools are implemented for each activity and integrated into the BDSE. The different types of knowledge associated with each activity are used to determine the level of automation and the interaction between the designer and the computer. A demonstration version of the BDSE addresses the design of the fenestration and the electric lighting system of office spaces with respect to comfort, energy, and cost. While this demonstration version is limited with respect to modeling capabilities and accuracy, it covers all types of design activities through the use of various tools, such as Issue-Based Information Systems, Expert Systems, Simulation Algorithms, Electronic Handbooks, Product Catalogs, and Case Studies. All tools are integrated within a multimedia-based environment that supports interactive use of computer graphics, electronic images, sound, animation and video.