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What to Watch for in Old Homes in Japan
In recent years, interest in Japan’s Akiya—abandoned or vacant houses—and low-cost pre-owned homes has been growing among overseas buyers.
With global inflation and the weakening yen, Japan’s used homes have drawn attention as low-cost investment opportunities or vacation-use properties.
However, these purchases sometimes lead to unexpected problems, such as costly repairs or concerns about safety after the transaction is completed.
While real estate brokers are not construction professionals in most countries, this limitation is compounded in Japan by a structural asymmetry of information.
Many properties are sold with limited disclosure, and brokers often provide only the legally required explanations—no more.
The lack of transparency and structural information asymmetry in Japan’s real estate market is another important factor.
You can read more about this issue here.
This is especially common in older homes with lower prices—where broker commissions are small and support is often limited to only what is legally required.
Because of how Japan’s real estate industry is structured, buyers who don’t actively seek out information may find themselves at a disadvantage.
Understanding key risk factors in advance is essential to making informed decisions.
This page summarizes the major building-related risks to watch for when purchasing an Akiya or other older home in Japan, especially for overseas buyers considering aged or vacant properties.
Related:
Explore the cultural and architectural value of Japan’s traditional homes—and what makes them so unique.
Akiya and Old Homes: Tips and Insights
Understand the appeal, risks, and realities of vacant and aged homes in Japan’s countryside.
Buying a Home in Japan: Tips and Insights
A practical starting point covering the key steps, costs, and post-purchase responsibilities in Japan.
Divided into categories, this Q&A guides you from the first property search through to becoming an owner.
Risks from Age and Vacancy
One of the first things to check when considering a used home in Japan is its construction year.
In recent years, interest in older homes and Akiya properties has grown as Japan promotes the reuse of vacant houses from a sustainability standpoint.
The market for pre-owned homes is expected to continue expanding, with various government programs supporting renovation and revitalization efforts.
Older homes often attract attention because of their affordability and potential for renovation.
They offer a chance to customize a home to your preferences, and many buyers enjoy the DIY process as a way to reduce costs and take part in creating their living space.
However, homes built decades ago carry their own set of risks.
While each property must be evaluated individually, there are some common warning signs and baseline risks that apply to older homes and long-vacant properties.
For details about how building age affects earthquake resistance and structural safety, please see this page.
Another important—but often overlooked—factor is the vacancy period.
The lifespan of a house is strongly influenced by how well it has been maintained over time.
If no one has been living in the property, routine maintenance is typically not performed—and small problems can go unnoticed and grow into larger ones.
In vacant homes—especially in rural areas—it is not uncommon for small animals and birds to enter and nest inside.
Even in urban settings, damage can be caused by rodents and insects.
Older homes often contain a greater proportion of natural materials—such as solid wood and traditional tatami flooring—compared to modern construction.
Combined with lower airtightness, these features can make vacant homes particularly attractive to animals.
Unlike modern houses, which are designed to minimize gaps and entry points, traditional homes tend to have more open or exposed features—such as attic compartments, rain shutters, or loosely sealed vents.
These elements, while part of the charm, can also make it easier for animals to find their way inside.
Examples include homes where rodents have nested in attic spaces and caused ceiling boards to rot from waste accumulation, or where birds have built nests inside rain shutter compartments, making them impossible to open or close.
In some cases, bird droppings have heavily stained upper floors and caused visible deterioration of flooring materials.
Another thing to watch for is remaining contents inside the house.
While a few pieces of furniture may not be a problem, homes filled with leftover belongings can suffer from poor ventilation and trapped moisture—especially in areas blocked by heavy items.
This can accelerate mold growth, decay, and damage to floorboards and other materials.
In addition, the surrounding environment of the house should be checked.
If the garden or exterior is overgrown, plants may block crawlspace vents or increase moisture near the foundation.
In Japan, termites thrive in humid conditions and typically enter wooden houses from the ground, not through the air.
When airflow under the floor is poor, termite activity can become more aggressive, and the combined effects of humidity, fungal growth, and decay can accelerate structural damage.
In older wooden homes, where ventilation and moisture control are essential, these risks often work together rather than in isolation.
Building age and vacancy period work together in ways that are not always visible during a simple walk-through.
When evaluating an older or vacant home, I recommend paying attention not only to how old the house is, but also how long it has been unoccupied, and how it has been managed during that time.
Roofs, Walls, Floors, and Tilt
The structural components of a house—such as the roof, walls, and floors—are interconnected, and their balance directly affects the overall safety of the building.
For example, if roofing materials are replaced with ones of a different weight, that change can alter the structural load, placing different levels of stress on the walls and foundation, and potentially affecting earthquake resistance.
Even if the roof and walls appear to be in good condition, the overall balance of the house may still be compromised if the supporting components—like the foundation or subfloor—are damaged.
Whenever possible, it's important to ask the seller about any repairs or reinforcements related to these structural elements, and to consider a professional assessment if needed.
When viewing a used home, people tend to focus on how clean it looks or whether it has been renovated.
But if you are seriously considering living there, it's the condition of the structure itself that should matter most.
Issues with the roof, walls, floors, or tilt of the building may not be obvious on the surface, yet they can significantly affect both safety and cost after purchase.
The Roof: Hard to See, Easy to Overlook
The condition of the roof is often overlooked during property viewings.
Even if it looks fine from the outside, the underlying structure may be deteriorating.
In one case, a seller said the roof had been repaired five years earlier.
However, it turned out that only a small section had received basic patchwork, while the rest of the roof had continued to deteriorate.
In two-story houses, you may be able to see the first-floor roof from an upstairs window.
If so, it’s a good idea to check for signs of staining, cracks, or other visible issues, as much as possible.
Wall Cracks: Hard to Judge at a Glance
In older homes, it’s not unusual to see cracks in the walls.
Some are due to aging over time, while others may have formed after earthquakes.
In one property I inspected, there was a deep crack in an inconspicuous part of the exterior wall that even the seller hadn’t noticed.
This shows why it’s important to check not only obvious areas but the entire structure carefully.
It’s often difficult to determine the seriousness of a crack just by looking.
If you notice cracks, it’s a good idea to ask the seller or broker about any history of repairs—whether reinforcement or repainting was done, and whether a timeline for future repairs was discussed.
If necessary, it may also be worth considering a professional inspection before purchase.
Floors That Feel Soft or Creak: Important Signs
When viewing a property, try walking around and checking how the floor feels.
If there are areas that feel soft underfoot or creak noticeably, they may indicate problems.
If such symptoms appear in areas near water, like the kitchen, washroom, or toilet, there’s a chance that past leaks or moisture have caused the flooring to deteriorate.
In some cases, not only the visible flooring, but also the structural material underneath may be damaged.
If left unaddressed, it could eventually affect the home’s earthquake resistance.
Sometimes surface replacement is enough, but in other cases, replacing the subfloor may be necessary—resulting in significantly different repair costs.
If you’re concerned, it’s a good idea to check whether an inspection is allowed, and to consider having a professional examine the property if needed.
Tilt: Easy to Miss, But Important
Tilt or unevenness is another issue that can be hard to notice during a short viewing.
You may feel something’s off if furniture doesn’t sit level or sliding doors are hard to open—but in many cases, people don’t notice until they’ve already moved in.
There are many possible causes for tilt, including changes in the ground or deterioration in the foundation.
A slight tilt doesn’t necessarily mean the building is unsafe, but it can affect comfort during daily life, and raise concerns about how the building will respond in an earthquake.
If you notice tilt or suspect unevenness, I recommend checking with the broker early on to see whether an inspection—such as one that includes slope measurements—can be arranged.
Unseen Infrastructure Risks in Older Homes
When viewing a property, people often focus on water-related facilities like the kitchen, bathroom, and toilet.
Because replacing these fixtures can be costly, buyers tend to be cautious.
However, in older homes that have been vacant for several years, the more serious problems often lie in areas that aren’t visible—behind the walls or under the floors.
Once a house is over 30 years old, it’s generally time to consider inspecting or replacing the plumbing system.
In vacant homes, pipe deterioration may go unnoticed for years.
If the house is old and there is no record of any plumbing inspection or replacement, it may be a good idea to consult a qualified contractor.
In many older homes, the water supply pipe leading into the house is only 13mm in diameter.
Depending on your household’s needs, it might be worth considering an upgrade to a 20mm pipe.
Gas lines are another area where aging and wear should be considered.
As with water pipes, the gas lines inside the property are the owner’s responsibility, and homes over 30 years old may be approaching the time for replacement.
In the case of propane gas (LP gas), it’s not uncommon to find tanks and meters still on the property.
This often happens because the gas company leaves the equipment behind in hopes of continuing service.
Buyers should know that propane service providers can be freely selected, and even if the equipment remains, there’s no obligation to keep using the same provider.
In some cases, you can ask the seller to have the equipment removed before transfer.
Electrical systems in older homes may also have deteriorated over time.
Worn wiring, weakened insulation, or outdated circuit breakers can all increase the risk of failure—and in the worst cases, fire.
If the home is over 30 years old, check whether inspections or updates have been done.
If this history is unclear or if there are concerns, it may be wise to have the system checked by a licensed electrician.
If the home has solar panels installed, you’ll also need to check when they were added, whether regular maintenance has been performed, and whether any transfer of ownership or paperwork is required.
In Japan, solar panel ownership often involves registration with the Ministry of Economy, Trade and Industry (METI).
These procedures can be complex, so working with an administrative scrivener may help streamline the process.
*In Tokyo, solar panels are now mandatory on new construction, and other regions like Kanagawa are beginning to follow suit.
Panels on older homes are generally owned outright, but newer installations may be under lease agreements.
Note: Leasing is only available to those with a residential address in Japan.
For non-resident buyers, leased panels are not an option—only ownership (buyout) is permitted.
Inspection
For older pre-owned homes, I recommend considering a professional inspection either before making an offer or before finalizing the transaction.
It can be difficult to accurately assess the condition of a home based solely on a viewing or the information provided by the seller or broker.
Depending on the current condition, structural reinforcement or repairs to the walls or roof may be necessary.
Without a proper inspection, you won’t know whether any reinforcement or repairs are needed to ensure the home is safe to use.
Even if the interior and visible fixtures look clean or newly replaced, in a country like Japan—where earthquakes are frequent, humidity is high, and typhoons are common—it’s still possible that important structural risks remain unresolved.
An inspection is also important in order to understand the current condition and plan appropriate maintenance to help extend the home's usable lifespan.
However, inspections are still not widely practiced in Japan.
Many brokers consider them a potential risk to closing the deal, and the idea of including one in the buying process is still not fully accepted.
If you want to request an inspection, it’s best to consult with your own real estate broker early and have them negotiate with the seller’s side.
In Japan, it’s not standard to conduct an inspection before making an offer.
You may be told to sign the contract first, or to go through with the purchase regardless of the results.
In some cases, your request may even be denied before closing.
On the other hand, inspections are allowed in many cases, so be aware that the response can vary depending on the situation.
I recommend confirming early on whether your offer can include a condition for inspection, whether an inspection will be allowed after the contract, and whether cancellation is possible if serious problems are found.
Clarifying these points in advance can help avoid problems later.
*In Japan, inspections generally require the client to be present, at least at the beginning and end.
If you live overseas and can’t attend, you can arrange for your broker or someone you trust to be there on your behalf.
You should also confirm payment options in advance, as some inspectors do not accept international transfers.
Be sure to coordinate with your broker on these logistical points as well.