We studied a model house system on cyberspace using JAVA and VRML in this paper. In the system, users can not only browse the model house using a web browser but also choose options that they want to install in the final house and the chosen options are combined with the figure of the model house on the terminal window in real time. In addition, the information of the chosen options are transferred to a database on a server machine at the construction company and the company can use the information for the customer management. The developed system can be used by a simple EC system since it includes duplex information paths.