Safety
Checking earthquake and flood risk for a Tokyo home: the building, the area, hazard maps and insurance
Four checks: the building’s earthquake standard, Tokyo’s district earthquake risk ranks, flood hazard maps, and earthquake insurance.
Japan has frequent earthquakes and heavy rain, so checking risk is a normal part of choosing a home. In Tokyo you can check four things with official sources: the building itself, the area it stands in, flood scenarios, and insurance.
Key takeaways
- Building: check it follows the new earthquake standard (building permit from June 1981)
- Area: Tokyo ranks earthquake risk for every district on a 1–5 scale (5 is the highest)
- Flood: hazard maps show river flooding, rainwater flooding and storm surge; brokers must explain them before the contract
- Insurance: fire insurance alone does not cover earthquake damage; add earthquake insurance
The building: its earthquake standard
Buildings permitted from 1 June 1981 are designed to the new earthquake standard. Homes completed in 1984 or later almost always are; for 1981–83, check the permit date. See our earthquake-standard guide for details.
The area: Tokyo’s district risk ranks
About every five years the Tokyo Metropolitan Government surveys earthquake risk by district. The 9th survey, published in September 2022, rates each of 5,192 districts for building collapse, fire and overall risk on five ranks.
Ranks are relative within Tokyo: rank 5 is the highest risk and rank 1 the lowest. Rank 1 does not mean no damage, so weigh it together with the building’s earthquake resistance.
| Risk | What it measures |
|---|---|
| Building collapse | The chance of buildings collapsing from shaking |
| Fire | The chance of earthquake fires spreading |
| Overall | Both of the above, plus how hard evacuation, firefighting and rescue would be |
Floods: read the hazard map
On the GSI “Kasaneru” hazard map, enter an address to overlay flood, storm-surge and landslide scenarios. Each ward also publishes hazard maps.
Since 28 August 2020, brokers must show the flood hazard maps (river flooding, rainwater flooding and storm surge) in the pre-contract disclosure briefing and point out the property’s approximate location. Being outside a flood zone does not mean there is no flood risk.
What to check in a condominium
- The unit’s floor and the expected flood depth (lower floors are more exposed)
- Any seismic assessment or retrofit (for older-standard buildings)
- The long-term repair plan and repair reserve
- The owners’ association insurance for common areas
Earthquake insurance
Fire insurance alone does not cover fire, collapse or other damage caused by an earthquake. Earthquake insurance is added to a fire policy, at 30–50% of the fire insurance amount, up to ¥50 million for the building and ¥10 million for contents.
Sources
FAQ
Is a rank 1 district safe?
It means relatively low risk within Tokyo, not no risk. Consider the building’s earthquake resistance too.
If an area is uncoloured on the hazard map, is there no flood risk?
No. Being outside a flood zone does not rule out flooding; the ministry asks brokers to make that clear.
Can I get earthquake insurance while living abroad?
It is added to the fire insurance for the Japanese property. Ask your property manager or an insurance agent.
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