These objects have only a limited number of parametric facilities. Floor slabs are intelligent composite objects, including floor finish, surface treatment, insulation and so on. Roof slabs are constructed in a similar way. Walls can also be composite objects and can be edited substantially after they have been placed. Plan, section and elevations are all integrated and associative views of the virtual model, and therefore any change in plan, elevation, section or 3D windows, has an immediate updating impact on the whole thing.
Plans are a top-down view of each floor.
Elevations are a side view and sections can be cut through the model on a staggered line. The whole building is constructed from intelligent objects that collectively create a virtual building model. All drawings are plotted directly from the 3D model and there is no need for separate drawing files. GDL is a highly efficient programming language, so 3D drawing files are kept small enough to generate a new model file whenever a major revision is made. GDL is easy to learn and freely available to users and there are literally thousands of objects that have already been created.