The interaction between the building service systems (electrical, mechanical and public health), the structure and the external facades can be extremely complex.  As the density of systems increase, spatial management becomes increasingly important to produce an efficient and well-integrated building. By utilizing a BIM model consists all necessary building disciplines and system components, it is totally capable to visualize the design conditions and manage coordination effectively, thereby improving confidence of the design and reducing the chance of design conflict / clashes / interferences due to late changes.