Quick answers
- How much does a full renovation of a house in Tokyo cost?
- Typically ¥160,000–250,000 per square metre of floor area (US$1,000–1,600) for insulation, windows, roof and walls, and kitchen and bathrooms. Earthquake strengthening and garden works are extra.
- Are the big house builders more expensive for renovation?
- Not necessarily. Quotes on the same specification, partner products and subsidies bring the cost down — and their ten-year warranty is worth comparing.
- How can I keep the cost of a layout change down?
- Leave load-bearing walls and the kitchen and bathrooms where they are. Moving partitions, doors and storage costs little.
We gather data objectively from the latest available sources and share what we find useful.
We hope it helps anyone looking for a home in Japan, or considering a business built around property.
We fully renovated a house over 30 years old. Here is what it costs per square metre today — and what kept our cost down.
Per m² of floor area. Earthquake strengthening and garden works are extra; an interior-only job costs less.
01What We Did
The budget went first to what you can only reach with the walls open — insulation — and to the roof and walls that protect the building.
| Part | Work |
|---|---|
| Insulation | Every room to Japan’s “next-generation” standard; ground floor insulated from below |
| Windows | Inner double-glazed windows almost throughout (LIXIL Inplus); a few frames replaced (LIXIL Thermos L) |
| Front door | Insulated door (LIXIL Recent) |
| Roof and walls | Walls: stain-resistant ceramic paint (SK Kaken Ceramiclean). Roof: silicone roof paint (SK Kaken Yane Fresh Si) |
| Floor heating | Hot-water floor heating (Noritz) in the living areas |
| Equipment | New kitchen, bathroom, toilets and water heater, with a ten-year warranty |
| Layout | Walls moved within what the structure allows |
02Big Builders Are Not Always Dearer
Costs have risen at the big house builders too, and a local builder can be cheaper for some jobs. What matters is comparing quotes.
1Compare like with like
Ask every company to quote on the same specification.
2Use partner products
Builders’ dedicated and bulk-bought products cost less for the same quality.
3Compare the aftercare
Big builders often give a ten-year equipment warranty and one contact for repairs.
4Plan around subsidies
Only registered window and insulation products qualify — fix the specification before signing.
03The Subsidies We Used
| Subsidy | Covers | Amount |
|---|---|---|
| National · Advanced Window Renovation | Inner windows, front door | about ¥1.1M |
| National · Child-rearing Eco Home | Energy-saving works | about ¥0.2M |
| Tokyo · insulation retrofit for existing homes | New insulation, ground-floor insulation | about ¥1.6M |
| Total | about ¥3M |
Where schemes overlapped, the builder chose the combination that paid most. Tokyo’s grant needs a full photo record; ours came about 7½ months after handover. Schemes change every year.
04Layout Changes: What Costs Most
The cost depends on what you move.
| Costs a lot | Costs little |
|---|---|
| CostlyMoving load-bearing walls, columns or beams | CheaperMoving partitions that carry no load |
| CostlyMoving the kitchen or bathrooms far | CheaperKeeping them in place, with new equipment |
| CostlyMoving the stairs or opening the floor | CheaperNew doors, storage and built-ins |
| CostlyResizing windows in the outside wall | CheaperAdding inner windows |
Which walls carry the load depends on the construction method and the drawings — ask the builder to mark them before you plan.
05Since April 2025: A Permit for Major Works
Even a two-storey timber house now needs a building permit if more than half of any one of the walls, columns, floors, beams, roof or stairs is repaired or altered. Structural layout changes or a new roof covering can trigger it.
- More cost and time: drawings and fees, and no start until approval.
- Upgrades to current standards: older houses without drawings may need extra work.
- Houses that cannot be rebuilt: without proper road access there is no permit, so the work is limited.
New finishes, new equipment or repainting usually need no permit.
06Costs Beyond the Works
Renovate after buying, and you cannot move in until it is finished — while your rent and the new loan both run. Air conditioners, curtains and furniture are extra.
07Or Buy One Already Renovated
Flats cost more to renovate too: about ¥130,000–200,000 per m² (US$800–1,300) — over ¥10 million for 70 m².
| Renovate it yourself | Buy it renovated | |
|---|---|---|
| Cost | YourselfToday’s prices, in full | RenovatedOften cheaper — the company’s buying power |
| Time | YourselfMonths of planning and works; no living there meanwhile | RenovatedSee it finished; move in at handover |
| Warranty | YourselfThe builder covers the work; a private seller often gives little or none | RenovatedFrom a property company: at least 2 years’ defect liability by law |
| Freedom | YourselfYour layout, your specification | RenovatedAlready decided |
With a renovated home, check how much of the pipework, wiring and insulation was renewed.
Over 30 years old, and still plenty of options
If the structure is sound, a flat or house over 30 years old is perfectly liveable — and a thorough renovation can feel close to new. It takes time and effort, but it is a real option.
Homes already renovated can be good value too: the renovating company’s buying prices often make them cheaper than doing the same work yourself. If you want value and a good location, they are worth looking through one by one.
Frequently Asked Questions
How much does a full renovation of a house in Tokyo cost?
Typically ¥160,000–250,000 per square metre of floor area (US$1,000–1,600) for insulation, windows, roof and walls, and kitchen and bathrooms. Earthquake strengthening and garden works are extra.
Are the big house builders more expensive for renovation?
Not necessarily. Quotes on the same specification, partner products and subsidies bring the cost down — and their ten-year warranty is worth comparing.
How can I keep the cost of a layout change down?
Leave load-bearing walls and the kitchen and bathrooms where they are. Moving partitions, doors and storage costs little.
Is a house over 30 years old still worth living in?
Yes, if the structure is sound. A full renovation can give a result close to new.
General information based on the sources listed, as of the date above. We check each figure against its source, but cannot guarantee that the information is complete, accurate or current. It is not legal, tax or investment advice; before any purchase, please rely on the original sources, the property’s disclosure statement and contract, and your own advisers.
