3D parametric and non-parametric modeling elements that can be used to graphically represent any model object including floor slabs, walls, beams, columns and roofs. A form can be a Parametric Frame Builder object (BXF file), a PC Studio parametric cell (PAZ file), a Compound Cell (BXC file), or a cell (CEL file). Forms are placed, modified and manipulated during 3D and 2D modeling, using tools specific to Building applications.