There have been many successful examples of Virtual Design Studio projects that have used a variety of network communication technologies, showing that interaction among participants enhances performance of the design team. However, the application of VDS techniques to a design studio program conventionally conducted in a studio space still seems to be limited, even though there is a clear need to improve interactions among students and teaching staff. The authors developed web-based groupware, GW-Notebook, and application techniques for a design studio program to enhance interaction in class hours in a studio space and also in off-studio hours, in which members work in separate locations. This paper discusses a model of communication and interaction in a collaborative design studio program conducted in a studio space. It also considers the major features of the developed system, the environment, and method of system usage in different teaching styles, and finally reviews performances of the latest system tested at junior collaborative design studio.