Abstract
Effective environmental improvement project has not been carried out successfully at existing small-scale residential development areas in the suburbs by now. But households living there are getting matured and their houses are entering the time for being re-built. Therefore they demand more and more for re-building their houses, and, at the same time, for the mitigation of building regulations, especially at the category I exclusive residential districts, where the volume and shape of buildings are strictly regulated. But it is very difficult to achieve both increase of living space and improvement of housing environment.
In this situation, some municipalities holding the category I exclusive residential districts are trying to cope with this problems by District Plan with the mitigation of floor-area ratio regulation and subsidiary project. The aim of this article is to evaluate the background, the planning process and the details of these trials, clarify their strong points and problems, andconsider the possibility to practice the method in the other areas or zones, especially the category II exclusive residential districts.
