Abstract:In this paper an object-based CAD programming is used to take advantage of standardization to handle the schematic design, sizing, layout for services in a building ceiling void. From the specification of the building 3D model, our software proceeds through different steps; from the determination of the standard number and size of fan coils to the generation of 3D solutions. In order to deal with more complex geometry and larger problems, we have used a hybrid approach: Case Based Reasoning (CBR) within Constraint Satisfaction Problem (CSP) approaches. In practice, engineers in building services use previous solutions and adapt them to new problems. CBR mirrors this practical approach and does help us to deal with increasingly complex geometry effectively, and meanwhile CSP has been used for layout adaptation. The results have shown that it is possible to define and implement standard solutions to produce designs comparable with current practice. The benchmarking exercise has underlined many advantages and made some suggestions for further development. This project is funded by The Engineering and Physical Sciences Research Council (EPSRC) in UK.