Yotsuya Corporas (The first Japanese condominium for sale 1956-2017)

Mansion in English refers to a detached luxury house. However, in Japanese, this word stands for a legally non-combustible condominium unit owned separately. In other words, it is a type of housing in which the dwelling units of a multi-family building, separately owned by individuals, are three-dimensionally connected in vertical and horizontal directions. Strictly speaking, a rental apartment should not be called a Mansion in Japan. However, from around 2000, the word has often been associated with an apartment if it has a reinforced structure. Thus, the meaning of the word has gradually changed over time.
 
In this case, why did rental apartments come to be called Mansions in Japan? The first condominiums for individuals emerged in Japan in 1956. This book draws its title from the name of the first property, "Yotsuya Corporas," when Mansion was not yet used. "Yotsuya Corporas" became so popular that similar condominiums successively appeared in Tokyo. One of them, named “Shinano-machi Asia Mansion,” was built in 1959, which marked the first time Mansion was used to refer to condominiums in Japan. In response to this, the number of properties claiming to be Mansions gradually increased, and soon, the term became a general noun that meant condominiums. The word Mansion has gained so much popularity that this phenomenon was repeated in 2000 and even rental apartments were called Mansions in Japan.
 
It is important to note that there are currently a total of over 60 million houses in Japan, around 10% of which are Mansions. The number of shelves in the houses increase each year, and the proportion increases in urban areas. In Tokyo, a quarter of the total number of houses is Mansions. Currently, repairing and rebuilding dilapidated Mansions has become a social issue, but they are managed based on “the compartmentalized ownership law” enacted in 1962, six years after the “Yotsuya Corporas” was built. This book argues that “Yotsuya Corporas” played a major role in enacting this law. Furthermore, this book explains the origins of “Yotsuya Corporas,” the first Japanese condominium for sale, which was rebuilt in 2017, and how it affected the condominium industry and condominium management.
 

(Written by OTSUKI Toshio, Professor, School of Engineering / 2021)