1. Zoning and buildable volume
Category I low-rise residential makes three storeys and roof gardens hard. Commercial sites allow them but compromise the residential ambience. Check fit-to-brief first.
2. Road frontage
Frontage road less than 4 m wide triggers setback that shrinks your buildable area. Private roads and "designated lanes" require notarised consent from neighbours.
3. Ground bearing
Never purchase without a Swedish Weight Sounding or borehole test. Soft ground adds JPY 2–5M of improvement cost. Osaka's Uemachi plateau is firm; the bay area is high-risk.
4. Hazard maps
Floods, landslides, tsunami, liquefaction — confirm against MLIT and city maps. Ashiya / Nishinomiya hillsides can be cliff-ordinance plots; bay plots have liquefaction risk.
5. Height differences and retaining walls
A 1 m+ height difference from the road triggers the cliff ordinance. Old retaining walls may need to be rebuilt for the new house (adding JPY 5–15M).
6. Boundaries
Future disputes start with unclear lines. Confirm a boundary survey has been completed; if not, require the seller to fund one.
7. Utilities
Verify the entry points and main pipe diameters for water, sewer, gas, and power. Areas without public sewer require septic tanks with ongoing running cost.
8. Encroachments
Neighbouring roofs, gutters, or trees may cross the line. Document any encroachment in writing.
9. Overlay regulations
Scenic preservation districts, landscape districts, district plans, and building covenants pile additional limits on top of zoning.
10. Neighbourhood feel
Walk the street at morning, afternoon, and night, both weekday and weekend. Lighting, noise, and pedestrian flow never appear in the brochure.
11. Price comparables
Cross-check against transaction histories (REINS), official land prices, and the MLIT property database. If a price feels too good, work out why.
12. Important-matters disclosure (juyojiko-setsumeisho)
A long document handed over just before contract. Read it side-by-side with your architect to catch design-killing clauses early.
We offer architect site visits during land hunting. It catches "won't actually build" plots before money moves.