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【Basic knowledge of real estate Vol.2】Area notation of Japanese apartments

  • Japanese real estate expertise
【Basic knowledge of real estate Vol.2】Area notation of Japanese apartments

When you open the brochure of the apartments in Japan, you can see the notation like the picture above. But is this notation the same as it is in your country?

For example, the area notation of apartments in Hong Kong, Taiwan, etc. is written as the total area of each unit and the common area (common hallway, main entrance, elevator, etc.), this also includes balcony and terrace.
In Japan, it is described as “Exclusively-owned area (専有面積)” in brochures of apartments. Let’s see what this “Exclusively-owned area” means.

Exclusively-owned area (専有面積):
Pronunciation in Japanese: Senyu-menseki
Simply put, it is the area of the unit only. The exclusively-owned area is calculated from the area inside the unit from the center line of the wall that surrounds each unit (center line of wall measurement floor area). Therefore, the area of other common area such as balcony, terrace and main entrance is not included.

In addition, the sales agreement for Japanese apartment has the area listed in the registry and indicate a slightly smaller area than the exclusively-owned area. This is because the calculation method of the area listed in the registry is different from the center line of the wall calculation, and only the area inside the wall of the unit (inner wall measurement floor area) is calculated.

Center line of wall measurement floor area (壁芯面積):


Inner wall measurement floor area (內法面積):
It can be said as “Floor area in the registry”. The area calculated from the inner wall of the unit which is slightly smaller than the area described in the brochure. This area will be the basis for tax calculation.


When purchasing apartments in overseas, be aware that the area notation varies depending on the country. If you just look at the area notation in Japan without the above knowledge, you may feel that the area of the unit is too small.
Those of you who are considering purchasing an apartment in Japan, please keep this knowledge in mind.

If you have any questions regarding Japanese real estate, etc., please feel free to ask us.


We would like to introduce the apartments that CLEARTH LIFE has recently started selling.


It’s located in Koto-ku, Tokyo where is close to lively commercial areas such as Tokyo Station.

Please find more details from the website:

 Apartments introduction movie:


Would you like to know more about CLEARTH LIFE projects?

Currently on Sale


Feel free to ask us any Japanese real estate related questions.

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Currently on Sale


    Tokyo’s Timeless Heritage

    Completion: March.2024 / Price: 34.4 Million JPY ~


    "Yokohama Sakuragucho" Timeless Radiance

    Completion: June.2007 / Price: 27.4 Million JPY ~


    "Kawasaki", Tradition Meets Tech Innovation

    Completion: December.2023 / Price: 36.4 Million JPY ~



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