JapanWhat is unit ownership of a building?
Unit ownership in Japan is a form of co-ownership where a person owns an individual unit (e.g., an apartment) and holds shared ownership of common areas, governed by the Act on Unit Ownership.
What the Law Says
Unit ownership is defined and regulated by Japan’s Act on Unit Ownership of Buildings, which establishes how individuals can own separate units while sharing ownership of structural and common parts of a building.
Under Japanese law, unit ownership allows a person to hold exclusive ownership of a specific part of a building — such as an apartment or office — while simultaneously holding joint ownership of common areas like hallways, staircases, elevators, roofs, and foundations.
The Act requires that unit ownership be established through a formal 'regulation' (bylaws) registered with the Legal Affairs Bureau. This regulation defines the boundaries of each unit, the scope of common areas, and rules for management and decision-making.
Decisions affecting common areas or management require resolutions at meetings of unit owners. Unless otherwise specified in the regulation, decisions are made by a majority of owners representing more than half the total voting rights.
Statutory Text‘Unit ownership’ means the ownership of a building divided into two or more units, each of which is separately owned, together with the co-ownership of the land and other parts of the building necessary for its use and enjoyment.
— Act on Unit Ownership of Buildings, Art. 2(1)
What to Do
Confirm your unit’s registered title and the building’s unit ownership regulation at the Legal Affairs Bureau.
Review the regulation to understand your rights and obligations regarding common areas and management fees.
Attend unit owner meetings and participate in votes — decisions often require a simple majority of voting rights.
Ensure management fees and repair fund contributions are paid regularly, as non-payment may lead to legal enforcement.
Sources
Not legal advice. This article is general information based on publicly available sources, written for educational purposes. Laws change and individual situations vary. Consult a licensed attorney in your jurisdiction before acting on anything you read here. Last reviewed: 2026-06-09.