Buying an Apartment in Japan: What a Mansion Actually Costs to Own

In Japanese listings a mansion (マンション) is not a large house. It is a steel or concrete apartment building, and a unit in one is what most people in Japanese cities actually buy. The word catches out almost every foreign buyer reading portals for the first time. A wooden two-storey house is a 一戸建て; the concrete block down the road is the mansion.

Buying a unit works differently from buying a house, and the difference is mostly about money that keeps leaving your account after the purchase closes.

The two monthly fees

Every mansion unit carries two recurring charges, billed monthly, entirely separate from any mortgage:

Together these commonly run tens of thousands of yen a month, and they are owed whether you live in the unit, rent it out, or leave it empty. A cheap unit with high fees can cost more per year than a dearer one with low fees. Compare the total, not the sticker.

The reserve is the number that separates good buildings from bad ones

The repair reserve is where an older mansion tells you the truth about itself.

Ask the agent for the 長期修繕計画 (long-term repair plan) and the current reserve balance. What you want to know is whether the plan and the balance agree. If the building is due for exterior work in three years and the fund is thin, one of two things is coming: a 一時金, a lump-sum levy on every owner, or a steep rise in the monthly reserve. Both land on whoever owns the unit at the time, and that may be you.

A rising reserve schedule is not a warning sign in itself. Many buildings deliberately start low and step up. A reserve that has never risen in twenty-five years, on a building that has never had scaffolding on it, is the warning sign.

Also ask who manages the building. A 自主管理 (self-managed) building, run by the owners' association without a management company, can be perfectly well run and is often cheaper. It can also mean no proper accounts, no repair plan, and no one chasing unpaid fees. Ask to see the association's minutes.

What you own, and what you only borrow

Your title covers the 専有部分, the exclusive portion: essentially the inside surfaces of your unit. The structure, the corridors, the roof, and the exterior walls are 共用部分, common property shared by all owners.

Balconies confuse people. A balcony is common property that you hold an exclusive right to use. It is also a designated fire escape route in most buildings, which is why you cannot enclose it, and why the partition to your neighbour is a thin board meant to be kicked through.

The land is handled through 敷地権, a land right attached to your unit and inseparable from it. You cannot sell the unit and keep the land share, which is exactly what you want.

The bylaws decide more than you expect

The 管理規約 (bylaws) and the accompanying 使用細則 are binding rules set by the owners' association. Read them before you sign, not after. They routinely govern:

If your plan for the unit depends on any of these, confirm it in the bylaws before the contract, not during the renovation quote.

Age, structure, and what it does to resale

Mansions do not follow the same value curve as wooden houses. The depreciation that flattens a detached house is slower in reinforced concrete, and a well-located unit near a major station can hold value in a way a rural house never will.

Two dates matter. Buildings confirmed under the 新耐震基準 from June 1981 onward are the usual dividing line for lenders and insurers, and the older seismic standards are worth understanding before you look at anything from the seventies. Buildings from around 2000 onward tend to have better insulation and pipe layouts that can be renewed without opening walls.

Within a single building, resale is driven by floor, orientation (south-facing carries a real premium), corner position, and whether the unit is above the neighbouring rooflines.

What to ask before you offer

  1. Current 管理費 and 修繕積立金, and the schedule of planned increases.
  2. Reserve fund balance, and the date of the next major works in the repair plan.
  3. Repair history: when the exterior, roof waterproofing, and pipes were last done.
  4. Delinquency rate on fees across the building. High arrears predict shortfalls.
  5. Number of units owned by investors versus residents, which shapes how the association votes.
  6. The bylaws, in full, plus the last two years of association minutes.

None of this is hidden. It is all in documents the seller's agent can obtain, and a seller who will not produce them has told you something useful.

Once you know the fee load, add it to the annual running costs you would pay on any property here, and compare the real yearly total against a house. Sometimes the mansion wins. Sometimes the fees quietly make it the more expensive option.