Abstract: In order to generate and represent property solids with exterior topology. Based on the existing floor-plans, this paper proposes a method to adopt the way of extruding floor-plans to create 3D models of property solids, and to use 3-combinatorial maps to represent interior and exterior topology of property solids. The results are as follows:(1) A delivery method of intervals is proposed based on incidence graphs with weight and incidence matrix. (2) According to the comparison relationship between old and new intervals, a method for generating darts of 3-combinatorial maps is proposed. (3) An algorithm for adding β relations of 3-combinatorial maps is proposed. Research conclusions show that property solids can be created by extrusion and 3-combinatorial maps, and represent interior and exterior topology of property solids and improve efficiency of constructing property solids.