A kominka (古民家) — a traditional timber house, often a farmhouse — is built in a fundamentally different way from a modern home. Understanding that is the key to restoring one well.
How they're built
Most kominka use traditional post-and-beam construction (伝統構法): large timbers joined with carpentry joints, often standing on foundation stones rather than a concrete slab, with earthen walls (土壁) and tiled or once-thatched roofs. They were designed to breathe and to flex, not to be sealed.
Where the money goes
- Roof — the first priority; water is what destroys old houses.
- Structure — rotten sill beams and posts near the ground, repaired by carpenters who know traditional joinery.
- Foundations and floors — levelling, damp-proofing, and dealing with termites.
- Services — wiring, plumbing, a modern bathroom and kitchen, and often a septic system.
- Comfort — insulation and draught-proofing that respect how the house breathes.
Budgets vary enormously: a careful restoration commonly runs from several million to tens of millions of yen, depending on condition and ambition. Get the structure and roof surveyed before you set a figure — the renovation cost calculator gives a first ballpark.
Running it from abroad
- Start with a survey, 3D scan and floorplan so you can plan without guessing.
- Agree the scope and budget in writing, with quotes from trades who know traditional houses.
- Insist on weekly progress photos and approval for any change.
- Plan the work around the seasons — roofing and exterior work before the rainy season and typhoons.
That's how our project management works. See our own Mie home before and after.
