The aim of this paper is to show how renewal to three-story houses prevent small-lot housing area from blighted, and consider how to conduct the renewal process to healthy environment of this type of housing area. The authors first have an overview on state of three-story houses in Tokyo, Saitama, Kanagawa and Chiba Prefectures, then survey the renewal process in a typical small-lot housing district in Saitama. They concluded that rebuilding to three-story houses by owner-residents made improve their living environment to the moderate level, and suggested the necessity of the method of control on renewal process through rebuilding on individual lot instead of redevelopment of whole district.
