In this study, we tried to clarify the design process of “Yotsuya Co-operative House” from documents, design drawings and measurement surveys. In January 1956, at the time of beginning to sell, the design had high independency with individual stairs on the first floor. In the design drawing in February, it seems that the design of common parts was completed. In July, layouts of each dwelling units were fixed. Changes of interior design were divided into four works: construction, electric, gas, and sanitation. From the measurement surveys in 2017, we clarified the detailed design of dwelling units and common facilities.
