Why a machiya quote looks like that

In short

• A machiya is not built the way the building code assumes, so a quote drawn up for an ordinary timber house does not carry over to one.

• Japanese law puts the owner of an old house under a duty to make the effort, not an absolute requirement to do the work. The scope is therefore a decision rather than a given.

• Since April 2025, major repair on any house of two storeys or more needs building confirmation, the approval you need before work starts, whatever the house is made of.

• Open the roof, find rot, and the job can cross that line mid-project. You stop there and file.

• Kyoto's landscape procedures run before the building confirmation, not alongside it, and the city publishes about two weeks for its design review where the design already meets its standards.

• Kyoto's earthquake and fire improvement subsidy pays eight tenths of eligible cost up to caps that depend on the frame's score before and after the work, and the city has said this expanded version of the scheme runs for the 2026 fiscal year only.

Ask three builders what a machiya renovation costs and you get three numbers with no common structure.

The reason is not that anyone is guessing. It is that most of what moves the figure is settled before pricing begins: how the building is built, which district it sits in, and what paperwork the work sets off. This article is about those three, because they are the part you can read for yourself.

The building is not what the code assumes

The building code's ordinary rules for timber houses assume a concrete foundation, a sill plate, posts tied down with metal connectors, and bracing or structural panels taking the horizontal load. A machiya typically has none of that. The posts often stand on foundation stones with no sill and no tie-down, the joints are cut timber rather than metal, and it is the earth-plastered walls, with the mud-walled panels above and below the openings, that take the shaking.

That is not a defect. It is a different structural system, and a structural engineering professor's submission to a Cabinet Office working group in 2018 put the consequence plainly: follow the ordinary timber specification and the building stops being traditional construction.

Two rounds of change, in 2016 and 2017, opened legal routes for traditional construction. A ministry notice first approved a method for joining a post to the foundation without tying it down with metal. Later notices recognised traditional wall specifications and, for ground-floor post bases only, allowed a post to lift where the house has enough wall quantity. Before that, a traditional detail usually had to be justified case by case with advanced structural calculation.

So any line item that touches structure is priced against a different rulebook. A builder who prices machiya work as if it were an ordinary house is either planning to convert it into one, or has not read the building yet.

What the law requires, and where the line moves mid-job

For an ordinary house of this size, the law imposes a duty to make the effort to strengthen it against earthquakes, not a requirement to carry out the work. The owner is expected to have the house assessed and to carry out work as necessary. Hotels and inns come under the stricter regime of instruction and public naming only at three storeys and 1,000 square metres of total floor area, which a two-storey machiya does not reach. The scope of structural work is therefore a judgement you make, not a quantity the law hands you.

What the law does fix is when you need permission to do the work at all.

Major repair or major alteration means work on over half of one or more of the principal structural parts, judged separately for walls, posts, beams, floors, roof and stairs. Since April 2025, for that work, confirmation is required on any building of two or more storeys or over 200 square metres. Timber houses used to have a looser line of their own, three storeys or 500 square metres, and the change removed the split by structure and brought timber down to the same threshold as everything else. Almost every two-storey machiya now sits inside it. On the ministry's guidance, work on the roof covering alone may be treated as falling outside the definition. So may work on the outer skin of the external wall, unless it amounts to renewing the whole of that wall.

Then there is the trap that pulls real quotes out of shape. The ministry has published the answer: strip the roof, find the substructure rotten, and if the work grows into major repair you stop and file for confirmation. A machiya quote that carries a contingency and a clause about opening up the structure is not padding. It is the one part of the document written by experience.

The procedures that finish before the work starts

Kyoto adds a layer that is invisible in a builder's price and very visible in a schedule.

Which procedure applies depends on the district and on the scale of the work. In the districts where the city has to certify the design, what sets the filing running for repair and alteration is not simply that the exterior changes. What matters is whether the part being worked on can be seen from public space or from neighbouring land. In the districts that take a notification instead, the trigger is size, in height and floor area. Where a building straddles the two, both procedures apply.

The two run in sequence with the confirmation, not in parallel. The ordinance requires the notification before you apply for confirmation, and in the certification districts nothing starts on site until the certificate is in hand. The city's published flow allows about two weeks for the design review where the design already meets its standards, and asks that both be completed before the building confirmation is filed.

None of that changes the price of a roof.

It changes when the roof can start, and a builder holding a slot has to price that risk somewhere.

The pattern is national, not Kyoto's alone. Confirmation for major repair applies to any house of two or more storeys anywhere in Japan. The duty to make the effort applies to any existing building that falls short of the current earthquake standards. What Kyoto adds is the design review in front of it.

The public money, and the date on it

Kyoto City runs a subsidy for earthquake and fire improvement work on machiya and timber houses. Under the 2026 fiscal year rules it pays eight tenths of eligible cost, capped by a figure that depends on the frame's structural score both before and after the work. For a machiya the cap is 3,000,000 yen where the work lifts a frame scoring under 1.0 to 1.0 or above, 1,500,000 yen where it lifts a frame scoring under 0.7 into the band between 0.7 and 1.0, and 1,000,000 yen where it improves the score without reaching either band. So a house already at 0.7 before the work falls into the last of the three, not the middle one. You receive whichever is smaller, the cap or eight tenths of eligible cost, and where two or more machiya on the same closed lane are strengthened at the same time, a further 500,000 yen each can be added.

Simplified work and fire work each carry their own smaller caps, and consumption tax is not eligible cost.

Two conditions matter more than the ceilings. If the house stands in a fire prevention or quasi fire prevention district, the full earthquake work has to be done together with fire improvement work. Those are the areas the city plan marks out for stricter fire-resistance rules. The subsidy rules put the pairing as a requirement, so the fire scope arrives with the structural scope rather than instead of it. The city has also stated that this expanded version of the scheme runs for the 2026 fiscal year only. Applications close on 25 December 2026, or earlier if the budget runs out, and completion reports are due by 1 March 2027.

Nationally there is an income tax credit for earthquake improvement work on a house you live in yourself, built on or before 31 May 1981. It runs to work carried out up to 31 December 2028. It is 10 per cent of a standard cost figure set by regulation rather than of your invoice, capped at 2,500,000 yen of that figure. Any subsidy you receive comes off the base before the 10 per cent is worked out. Public money does not stack. One source comes off before the next is counted.

Every figure in this article comes from a published rule with a year attached. What a specific house costs is a question for a builder standing inside it, and the paperwork listed in the machiya due diligence article is what that builder needs before pricing anything.

Questions buyers ask

Do I have to strengthen a machiya against earthquakes? Not as an absolute requirement. For an ordinary house of this size, what the statute imposes is a duty to make the effort: to have the building assessed and to carry out work as necessary. It turns decisive at the subsidy, where the caps depend on the frame's score before and after the work, so the target score and the budget are one decision.

Will my renovation need a building confirmation? On a house of two or more storeys, yes, if the work touches over half of any one principal structural part. Work on the roof covering alone, or on the outer skin of the external wall alone, may be treated as falling outside it, on the ministry's guidance. The honest answer for an old house is that nobody knows the full scope until the structure is open.

Why is the schedule longer than the work? Because the landscape procedure runs before the confirmation, and the confirmation before the work. The city allows about two weeks for the design review, and that figure assumes the design already meets its standards, so nothing about a revision sits inside it.

Is the subsidy worth building the plan around? It is worth checking straight away. The city has said this expanded version runs for the 2026 fiscal year only, and applications close on 25 December 2026 or when the budget runs out. Whether the budget still has room on any given day is not published, so ask the city's housing centre before you plan around it. In a fire prevention or quasi fire prevention district, too, the full earthquake work has to be paired with fire work, which enlarges the scope as well as the support.

Why will nobody give me a price per square metre? Because area is not what sets the price. The structural system does, along with the district, the score you aim at, and whatever the roof turns out to be hiding. A number per square metre would be a guess dressed as a rate.

A machiya quote is a reading of a specific building against these rules, which is why two houses on the same lane are priced differently and correctly. If you want the paperwork in order before anyone prices the job, tell moogo what you are looking at.

Written against published law and official sources as of 26 August 2026; rules change. 081株式会社 is a licensed real estate broker, not a tax or legal practice. This is general information, not advice on your situation, and case-specific decisions rest with the competent authority and your own professional.