This paper is focus on 3D virtual building design technic that construction materials are showed by components and these components are part of patterns, and building design using pattern is possible. To use this technique in process of construction, design, analysis, change, assembly, etc, we will develop flexible building design system that it supports efficient building change and low cost by construction design simulation. Specially also the designer and the user use a pattern and easily will be able to change the building and according to change pattern information of the materials, design of the buildings which are changed creates automatic. Also we will implement knowledge retrieval engine which is necessary to personal skill or visualization.