"We have been developing an exercise program named "architectural planning and design" (for 55 3rd grade students for one year) in Niigata University. In this practical program, students get experience as architectural professionals by designing and actually building the traditional wooden arcades named "Gangi". This is a sustainable and collaborative activity for preserving a traditional environment in this city. "Gangi" are the traditional arcades for snowy districts covering the pedestrian spaces against the falling snow. They are also one of the important elements in city landscapes in Tochio Nagaoka city. In Tochio Nagaoka city, there are a lot of "Gangi" that are broken and have not been repaired. They are owned by all of the inhabitants whose properties face the front road and are open for the use of all the inhabitants. This is the traditional way of life for the inhabitants in snowy districts. Because that most of the inhabitants are old, they do not afford to repair and re-construct them. We are building the "Gangi" in the collaboration with the inhabitants of Tochio Nagaoka city. From 2000, we started to re-build the "Gangi". The processes and the activities changed to some degree according to the condition of the construction site and circumstances. The main process is as follows. 1) Town planning orientation in April, 2) Team making with the students and inhabitants in May, 3) Researching the planning site and Omotemachi in June, 4) Discussing the design with the inhabitants in July, 5) Competition for the design in September, 6) Practical design control in October, 7) Construction of the new "Gangi" from November to February. In order to continue our activities, we have managed to clear many difficulties and create many new and characteristic structures as follows. 1) Supporting activity: we create competitive conditions. Inhabitants make the final decision. 2) Sustainable activity: All of the local media inform each activity to the inhabitants. We manage sustainable budgets by the government and local authority. 3) Environmental quality control: We maintain the diversity of our works by not keeping to the ordinary criteria for design. The "Gangi" are constructed with natural materials and utilizing local traditional industries. In Tochio, our new works are superimposed on the traditional landscape. I think these kinds of educational programs have a new possibility to preserve and develop the small town environment. Our activities got some prizes of the government of Japan. "