Integration of sustainable energy systems in the conceptual stages of building design is too complex. The communication between architect and contributing building services consultants is difficult. A model of design support has been extended, Methodical Design. In 2000, the Royal Institute of Netherlands Architects, BNA, De Dutch Society for Building Services (TVVL), and the Delft University of Technology, TUD, have started a research project Integral Design. In this project the new conceptual support framework was used in a series of workshops for architects and HVAC consultant. The results are promising. After the end of the project, a new research is started from within the Knowledge Centre Building & Systems, in which TU/e and TNO Bouw work together. This will result in a new series of workshops in which members of BNA and the Dutch Organisation of Consultants, ONRI, will participate.