Word of the Day - January 23, 2019

Senyou Menseki – 専用面積 – Real Estate Japan’s Word of the Day

Senyou Menseki


  • English definition: Exclusive floor area
  • In a condominium building, this is the floor area of the unit that is owned by each individual unit owner, specifically, the internal floor area of each dwelling unit.
  • It’s important to note that balconies, although attached to individual condominium units, are considered common-use areas, and not exclusive use areas, so they are not included in the exclusive floor area measurement. This is why you will sometimes see “for sale” condominiums advertised as having an “exclusive floor area of 60-sqm plus a balcony”. This is to let you know that there is a balcony attached to the apartment but that legally, it is not considered part of the actual exclusive-use area that you would be buying.
  • There are two methods of measuring the exclusive floor areauchi-nori (内法, literally “inner measurement”) and kabe-shin (壁心, literally “wall core”).
    • Using the uchi-nori method, the exclusive floor area measurements are taken using the inner dimensions of the actual usable part of the apartment, up to the wall.
    • In the kabe-shin method, the measurements are taken from an imaginary line running through the center line of each wall perpendicular to the floor. The kabe-shin method, of course, would result in a larger exclusive floor area.
  • For information on what counts as exclusive-use versus common-use areas, in a condominium building, please see: Know your Japanese condominium: Common use versus private areas