The paper describes a first prototype constructed in search for a central object model. It presents all possible data, concepts and operations concerning the architectural design process in the early phases. A central model of the process of design is essential: going from one design phase into another, the model describes geometrical shapes, abstract concepts like space and activity, concrete physical building elements and the basic operations all these entities undertake. Emphasis is put on combining all these different viewpoints, thus enabling the designer to use a broad range of design strategies. The aim is to help him and not steer or even hamper his creative process. Information necessary toassist the user of the system concerning energy calculation, stability checks etc can be extracted. By means of appropriate interfaces not only those tests built on top of the system but also existing software packages can make use of the modelis object structure. The implemented object model is one of the cornerstones of the IDEA+ project, aiming to provide an Integrated Design Environment for Architecture.