The Method of Evaluating The Potential for Conversion Legal Problems with Conversion And Basic Capacity of Vacant Onces in Tokyo

In Japan, the vacancy rates of office buildings have been at high in big cities since 1992. This problem is especially acute in Tokyo, where it is estimated that over 2.27 million square meters of office floor area will be oversupplied in 2003: big urban redevelopment projects will be completed in 2003. Under these circumstances, International Cooperative Research and Development on Sustainable Urban Management by Conversion of Buildings, called “SUMCOB”, has been carried out. This research aims to regenerate urban areas by converting redundant offices into flats, although instances of conversion are still very few in Japan. This paper introduces part of current results by SUMCOB, and discusses legal problems with conversion and basic capacity of vacant offices in Tokyo. It has been confirmed that there are no constraints concerned with Real Estate Registration Law (although it requires the change of the registration after conversion). and City Planning Law. However, some criteria are incompatible with Building Standard Law and Fire Service Law if the use of the building is changed from offices to flats. Typical incompatibility between offices and flats is lightening. If the buildings do not satisfy criteria for flats, the cost of renovation works for conversion will increase. To examine the basic capacity of vacant office buildings for conversion, field surveys in Tokyo have carried out at three areas: Kodenmacho (Chuo-ku), Toranomon (Minato-ku), and Iwamonocho (Chiyoda-ku). They are typical office areas that are included in center core of Tokyo. In Chuo-ku, the oldest commercial area in Tokyo, textile merchants have been located their headquarters. In Minato-ku, many rental office buildings have been located and several large scale redevelopments are advancing. Chiyoda-ku includes Marunouchi area, which is the prime office area in Japan. Thirty percent of the buildings in survey areas suffer from over twenty percent vacant floor rate, and fifty five percent were constructed before 1990. Especially most of buildings over forty percent vacant floor rate were constructed in 1980s. Vacant office problems haven't been seen in old buildings in Tokyo yet. The number of dwelling units made from office space will influence the conversion scheme. Seventy percent of the office buildings in survey areas have floor area of less than two hundred square meters. If they have been subdivided into two bedrooms type or three bedrooms type, the number of dwelling units in a floor would be less than three. The difficulty of conversion planning derives from frontage size, depth size, and their proportion. The five categories are proposed to grasp actual requirements for converting offices into flats.