6-chome of Hiyoshi-cho, Nagata-ku is located on the north side of substantially the center of Takatori-higashi first district, zoned as a disaster rehabilitation land readjustment district. In this district, collective replotting adopted during the land readjustment process was effectively used. Those who have the small sites that would be difficult to build and were interested in the joint housing project were identified among owners of small housing sites within the district, and the scattered sites of the candidates could be collected into one site. Usually, a repoltted lot in a land readjustment project is not largely moved from a current housing site. In this project, however, the dotted small housing sites owned by the candidates for the project could be collected into one site through cooperation of the landowners that owned large land within the district. For attaining such collective replotting, it is necessary to frame a plan for rebuilding joint housing after the replotting as well as to value the land concerned. Participants must have the will to join in the project, and to secure a substituted lot. The collective replotting can be also affected by a replotting plan of the entire district, and it is the first hurdle whether or not the sites of the candidates can be collected. However, it is because the area is included in the land readjustment district that the scattered sites of the candidates can be collected. In this project, 14 candidates could get a communal building site with the cooperation of landowners of large land. It was difficult for the candidates to rebuild detached houses in the individual sites because the sites owned by most of the candidates were as small as 30 through 40m2 and most of the candidates were the aged. The joint housing project effectively used a group subdivision system, in which the land resulting from the collective replotting is once granted to the Housing and Urban Development Corporation, a developer, and the candidates are granted floors of the housing built by the Corporation. Thus, the area of a dwelling unit in the rebuilt housing could be approximately 1.2 times as large as that of the previous housing site. In order to secure the equivalent exchange with the floor area approximately 1.2 times as large as that of the previous housing site and to decrease the costs to participants, it is necessary to make the reserved floor area that could be sold as large as possible. When the proceeds of the reserved floor area are equal to the construction expenses, a share in the expenses of the rightful persons can be zero. However, even when an inner type comprehensive design system was utilized, the building coverage could be increased from 200% by only 50%, and it was difficult to enlarge the reserved floor area. Therefore, the construction expenses should be held down to the utmost. Under such circumstances, the support by the Jushiso, which corresponds to merely less than 20% of the total construction expenses, played a significant role. The joint housing project of "San Koto Takatori" could be realized because all of the 14 candidates were landowners, and hence, there was no complicated relationship in the rights as in other joint housing projects. In addition, they shared an earnest wish that the joint housing project was the only way that they could measure to have them live in 6-chome of Hiyoshi-cho again.