To support automation and robotisation for construction, there are many requirements. A very basic one is the availability of the information about the building or structure to be constructed. The information may include the design of all the specialties in the building. The format of the geometry of the building elements should be in 3D. This can facilitate the construction simulation, planning and scheduling and rehearsal of the construction using robots. The paper introduces a system only concerns the part of the design that can be tailored to support the automation of the construction process. It is a system that uses 3D as its geometry data format which can integrate all the design in a proper form, supporting composition and decomposition of building elements arbitrarily according to the needs of construction process. It also supports group discussion and decision making.