Leaving Your Japanese House Empty for Months: The Checklist Nobody Gives You

Nobody hands you this list at completion. The judicial scrivener finishes the registration, the agent shakes your hand, and the practical business of owning a house in a country you do not live in starts the moment you lock the door behind you.

Most of what goes wrong in an empty Japanese house is cheap and easy to prevent, and expensive to fix after the fact. This is the list, in the order that matters.

At a glance

What goes wrong	How long it takes	Prevention
Drain smell and insects	2–4 weeks	Fill every trap, add a little cooking oil
Burst supply pipe	One cold night	Drain the water, or leave the power on
Mould on walls and futons	One rainy season	Leave interior doors open, dehumidifier or ventilation
Post box overflowing	2–3 months	A Japanese address that receives for you
Garden visibly overgrown	One summer	Arrange cutting twice a year
Unpaid property tax	One spring	Appoint a tax representative

1. The drains — the one almost everybody gets wrong

Every sink, bath, shower and washing machine outlet in a Japanese house has a water seal in the trap below it. That small amount of standing water is the only thing between your living room and the drain system.

Water evaporates. In an empty house in summer, a trap can dry out in two to four weeks. After that the smell comes back up the pipe, and so do the insects that live in it. Owners return after six months, open the door, and conclude that something is badly wrong with the house. Nothing is wrong with the house.

Before you leave:

• Run every tap and flush every toilet so each trap is full.
• Pour a little cooking oil into each drain afterwards. The oil floats on the water and slows evaporation dramatically — this is standard practice in Japan for a reason.
• Do not forget the ones you never use: the second bathroom, the outdoor tap, the washing machine drain, the floor drain in the bathroom.

If the house will be empty longer than about three months, the better answer is somebody running the taps while you are away.

2. Water and freezing

If your house is anywhere that sees sub-zero nights — and that includes far more of Japan than foreign buyers expect — a supply pipe can split in a single night, then flood the house when it thaws.

There are two safe strategies, and one dangerous one.

• Safe: drain the system. In cold regions houses are fitted with a drain valve for exactly this. Close the stopcock, open the drain, then open the taps so the pipes empty. This is the standard approach for an empty house over winter.
• Safe: leave the power on. Pipes in snow regions are wrapped in electric freeze-prevention heaters that switch themselves on in the cold.
• Dangerous: switch off the main breaker and leave the water in. This is the combination that bursts pipes, and it is the one people choose because turning everything off feels responsible.

Our guide to winterising an empty Japanese house goes through this in detail, including the water heater, which is usually the first thing to split.

3. Electricity — think before you cut it

Switching the supply off saves the monthly base charge and almost nothing else. What it costs you:

• Freeze-prevention heaters stop working.
• Any ventilation or dehumidifier stops, in a climate where the rainy season does the rest.
• Nothing on the property can be checked or run remotely.
• A house with no light at all, ever, reads as abandoned.

For most second homes the sensible answer is to keep electricity connected and shut off individual circuits you do not need. We work through the arithmetic in utilities in a Japanese second home.

4. Gas — close the valve, and understand what restarting means

Close the main gas valve before you leave. That part is simple.

The part that catches people out is the return journey. Gas is the one utility that cannot be restarted remotely. Whether you are on mains gas or LP cylinders, reopening the supply requires an appointment at which somebody has to be physically inside the house while the technician checks for leaks and lights the appliances.

If you are flying in for ten days, that means either arranging the appointment weeks ahead and losing part of your first day to it, or arriving to a house with no hot water. It is the single strongest practical argument for having somebody in Japan who can let a technician in.

5. The post box

Japanese organisations communicate on paper. In six months a second home accumulates tax notices, utility bills, insurance renewals, local government circulars and, if you are in a condominium, management association papers.

Two things follow:

• The street can see it. An overflowing post box is the most visible sign that nobody is attending the property, and it is what prompts neighbours to start making calls.
• Japan Post cannot solve it. The forwarding service (転送届) runs for one year and does not forward internationally. There is no version of it that posts your Japanese mail to you abroad as a matter of course.

The workable answer is a Japanese address that receives and scans for you. See how Japanese mail forwarding actually works for non-residents.

6. The garden, and what the neighbours see

In a Japanese summer an unattended garden becomes unmistakable within one season. This is not only cosmetic.

Under the Vacant Houses Special Measures Act a property that is visibly not being managed can be designated a poorly-managed vacant house (管理不全空家). The consequence that matters is financial: the designation removes the residential land tax reduction, and the fixed asset tax bill can rise several times over.

Arrange cutting twice a year — early summer and early autumn covers most of it. If your house is in snow country, arrange for the roof as well; in heavy-snow areas an unattended roof is a structural question, not an aesthetic one.

And introduce yourself to the neighbours on your first visit. A neighbour who knows the house belongs to somebody who comes back will call you about a broken window. A neighbour who thinks it is abandoned will call the city.

7. Insurance

Tell your insurer how the house is actually used. A property that stands empty for most of the year is not always treated the same way as one in regular use, and in Japan a building that is genuinely unoccupied may fall into a different classification with different cover.

Finding this out at claim time is the expensive way to find out. Our guide to property insurance for overseas owners covers what to ask, including earthquake cover, which is a separate product.

8. The tax notice — the one that actually costs money

Everything above is about the building. This one is about the bill.

Fixed asset tax notices are posted, on paper, in Japanese, to an address in Japan, usually between April and June. If nobody receives them, the tax goes unpaid, late charges accrue, and the first you hear of it may be a demand or a seizure procedure against a house you thought was fine.

The fix is a tax representative (納税管理人): a person or company in Japan registered with your municipality to receive and pay these notices on your behalf. It is a notification form, not a court process. See how to appoint one, and note that the owner on 1 January is liable for that whole year.

The checklist

1. Run every tap and flush every toilet, then pour cooking oil into each drain.
2. Drain the water system, or confirm the freeze-prevention heaters have power.
3. Decide deliberately what stays connected — do not default to switching everything off.
4. Close the main gas valve.
5. Leave interior doors and wardrobes open so air can move.
6. Store futons and bedding dry and off the floor.
7. Empty the fridge and leave the door propped open.
8. Close shutters on the weather side; leave a trickle of ventilation if you have it.
9. Arrange garden cutting, and snow clearing if relevant.
10. Make sure somebody in Japan can receive the post.
11. Confirm your insurer knows how the house is used.
12. Photograph every room before you lock up — it is the only record you will have.

How Japan YES helps

We are the address in Japan for owners who live abroad. The post comes to us, we scan and translate it, we pay the bills from funds you send, and we arrange the people who need to be at the house — the gardener, the gas technician, the plumber — so that a trip home is not spent on appointments.

Plans start at ¥66,000 a year, tax included. See how it works for a second home, or tell us about the property.

This article describes general practice. Freezing risk, insurance classification and local vacant-house rules vary by region and by provider — check the position for your own property.