Two kinds of question

Everything worth checking about a Japanese property falls into one of two categories, and confusing them is the most expensive mistake an overseas buyer makes.

The first kind has a recorded answer. Zoning, permitted floor area, hazard designations, official land values, the shape of the ground. These can be looked up from anywhere in the world, and we do exactly that in a property research session.

The second kind has no recorded answer. Somebody has to go and look, or ask a person, or wait until a particular hour of a particular day. No dataset contains it. This article is about that second kind.

Whether you can build on it again

Start here. Every other question is smaller than this one.

A building can stand on land that could not be replaced if it were demolished. Japanese law generally requires a plot to have adequate frontage onto a road that qualifies under the Building Standards Act before a new building may be approved on it. Plots that fail this test still hold houses, are still bought and sold, and are worth a fraction of what an equivalent buildable plot is worth.

This status is rarely stated in an English-language listing, and it is not visible in a photograph. A strip of asphalt wide enough to drive down is not necessarily a road in the legal sense. Frontage that looks generous may be measured differently by the rules than by the eye.

Ask the municipal building guidance counter directly: is the plot buildable, and against which road. It is a free question with a definite answer, and it can be asked before you make an offer. How the rule works, and what changed in 2025, is set out in the land you can never build on again.

The road itself deserves its own visit

Several separate matters attach to the road in front of a property, and they are usually discovered one at a time, in the wrong order.

• Whether the road is public or private. Private roads are owned by somebody, often several somebodies, and using or excavating them may require their agreement.
• Whether you would own a share of it, and whether that share transfers cleanly with the sale.
• Whether the road is narrower than the standard width, in which case rebuilding may require setting the new building back from the current line, reducing the land you can actually use.
• Whether the utilities under it serve your plot, and whether the connections are yours or shared.

The last one is worth checking on the ground and against the utility provider. A property that appears connected may be drawing supply through a neighbour's line under an arrangement that predates everyone involved.

Where the boundary actually is

Registered land area is a record, not a measurement taken recently. Older registrations in particular can differ from what a modern survey would find, for reasons set out in the land area in the listing is a historical record.

The questions to answer are simple and the consequences of skipping them are not.

• Are there physical boundary markers on the ground, and do they match the plan?
• Does a confirmed survey exist, agreed with every adjoining owner, and how old is it?
• Does anything cross the line in either direction? Eaves, gutters, walls, tree branches, pipes and fences all do this routinely, and each one is a negotiation waiting to happen after you own the place.

If no confirmed survey exists, decide before contract whose responsibility it is to produce one and who pays. It is a normal thing to negotiate. It is not a normal thing to discover afterwards.

Retaining walls and made ground

On any sloping site, the retaining wall is the largest concealed liability on the property, and replacing one can cost more than the building it protects.

What to establish: when it was built, whether it was approved and inspected, whether it is a single structure or one wall stacked on another, and whether it belongs to you or to the neighbour above or below. Look for bulging, cracking, leaning, and whether the drainage holes through the face are clear or blocked. Blocked drainage is what turns a wall into a failure.

Ground that was cut or filled to create a level plot behaves differently from ground that was always level, and since 2023 filled ground has its own regulated areas. The wall itself is covered in detail in the wall holding up the land is part of what you are buying, and mapped hazards in how to read a Japanese hazard map.

The building's paperwork, and whether it matches the building

Two documents matter more than the rest: the confirmation that the design was approved before construction, and the certificate that the completed building was inspected and passed. Older houses frequently lack the second one. Its absence complicates lending, insurance and any future alteration.

Then compare the paperwork with reality. Extensions, converted outbuildings and enclosed balconies are often built without being registered, which means the building on the register and the building on the site are different objects. That gap becomes your problem on the day you try to sell, insure or borrow against it.

For an older house, also ask when the roof, the exterior walls, the wiring, the water supply and the drainage were last replaced. Not whether they work. When they were replaced. Which structural rules the house was built under is covered in two dates decide how a house behaves in an earthquake, and what to look at inside in the two rooms nobody opens during a viewing.

If it is an apartment, buy the management as well as the flat

With a condominium you are acquiring a share in a collective, and the collective's condition matters as much as the unit's.

• How much is in the repair reserve fund, and how does that compare with the long-term repair plan?
• Are other owners in arrears, and how many?
• Is an increase in monthly charges scheduled or under discussion?
• When was the last major repair, and what is next on the plan?
• What do the recent meeting minutes say? They are the most honest document in the building.

A cheap unit in a building with an empty reserve fund is not cheap. It is an unbilled cost with a date on it. The full picture is in buying an apartment means buying the building's finances.

The things that only appear in person

Some conditions cannot be recorded because they are not facts about the property. They are facts about the situation around it.

Visit at more than one hour of the day, and if you can, in more than one kind of weather. A quiet street at eleven in the morning is a different place at seven in the evening, and again at seven on a Sunday. Note where water goes when it rains, where the sun falls in the afternoon, and what the neighbouring buildings do to both.

In rural areas, ask what the local community expects of residents. Shared maintenance duties, association fees and rotas exist in many places and are rarely written into anything you will be shown. They are not obstacles, but they are commitments, and discovering them after you arrive is a poor introduction.

Which counter holds which answer

Most of this is available, free, from people whose job is to answer. They will not approach you, and they will not add anything you did not ask for. The skill is knowing which door to knock on.

Two of those rows have their own guides: sometimes you buy the house and rent the ground it stands on, and the land category can stop the sale entirely.

Where this fits in the process

The recorded questions are worth settling first, because they are fast, they cost nothing to ask and they eliminate properties before anyone books a flight. The unrecorded ones come second, applied only to the properties that survived.

If you are earlier than this, the full guide to buying property in Japan as a foreign buyer sets out the sequence. If you are further along and already own something, the tax paperwork nobody mentions covers what arrives afterwards.