The quality of the indoor climate of buildings is the result of design decisions that architects make. In order to have the ability to correctly design indoor climate, designers need feedback on the performance of the design. Indoor climate analysis may provide this type of feedback. This research aimed to improve the design process on the aspect of indoor climate by providing architects with information. It attempted to develop a computer environment that stimulates integration of indoor climate analysis into architectural design. This environment linked the available design information to analysis tools in order to arrive at building performance predictions. Several techniques were researched and employed to reduce the gap between design and analysis. Control over aspects such as temperature, air quality and light is important to the short-term as well as the long-term well being of humans. The domain of indoor climate researches the perception of indoor comfort and designs well being as a part of the built environment. In order to balance building and indoor climate, information on building behavior is compulsory. Currently available temperature and airflow analysis tools can provide design information on these aspects. Designers often use CAD tools to make design representations. Our environment linked these representations to analysis tools to provide simplified access to these tools. Drawing methods and automated recognition algorithms were used to transform early representations into an organized information structures. Most conceptual architectural designs contain little information on building services or service concepts. Service information however, is essential if the analysis is to support assessment of indoor comfort. The representations of completed projects contain information that can provide architects with ideas and solutions. In our environment, information from precedents is used to support the definition of building service concept for the calculations. Indoor climate analysis results consist of large amounts of numbers for velocities, temperatures, etc. Designers find it hard to relate to this data and have difficulties in drawing conclusions from large tables of figures. Scientific Visualization can provide architects with information on the indoor climate in a comprehensible and abstract form. Visualization techniques such as particle tracing and isometric surface construction are used to provide overviews of climate parameters facilitate identification of problem areas. Designers can now interact with the analysis results instead of being confronted with data they do not understand. The application of indoor climate analysis in design can be supported by design scenarios. These scenarios are a set of focus areas that isolate particular design aspects and link to predefined analysis scenarios. Architects are able to pinpoint various design aspects such as façade type and building mass and receive guidance in performing the corresponding indoor climate analysis and interpretation of results. Various tests with students of architecture show that execution of indoor climate analysis during early design is possible. In the context of the exercise assignment, a small improvement in performance of the designs on the area of indoor climate was noticed. In most cases, the availability of design tools supported students in gaining knowledge regarding the relation of external factors and building behavior. Another exercise made clear that the use of our design environment did have a positive effect on the performance of students with regard to the indoor "awareness" of their designs.