A unique aspect of Japanese housing is that dwellings are assumed to have a limited lifespan and are normally demolished and rebuilt after a few decades, usually twenty years for timber buildings and thirty years for concrete buildings—see rules for specifics. This is in contrast to homes in the West which may be lived in for many generations by the same family.
When a house in Japan becomes outdated or no longer viable, it can be torn down or converted into another use. The decision on what to do with an old house depends on how much it costs to renovate it vs how much it would cost to build a new one. If rebuilding it is not feasible, then it may be better to tear it down.
Japanese houses are typically built with wood or concrete. Wood is often used for exterior walls and interior partitions while concrete is often used for the floor. Both materials are easy to work with and each has its advantages. Concrete is more durable if properly done while wood is more affordable but will deteriorate over time if not treated regularly.
Traditional Japanese houses had only two stories with small windows and low-pitched roofs. The interior walls were filled with furniture including beds made of bamboo and mats on the floor. There were no bathrooms as such since people went outside to take care of business.
The first is that Japanese dwellings are only supposed to endure 30 years. The belief that Japanese houses self-destruct after three decades is a result of the government's goal to keep the economy humming with a steady need for residential building, since the 30-year time restriction was devised by the Land Ministry. If buildings were left up too long, then new ones would have to be built instead of vehicles being manufactured, which would stifle the economy.
During World War II, the government banned the use of wood for housing, as well as any other material that could be used to make weapons. This allowed Japanese builders to use materials that wouldn't be available after the war, such as concrete and steel. But even though these newer materials were more durable, the old traditions remained intact: after 30 years, the house would be torn down and replaced with a new one.
This policy caused problems during the postwar period when there was a shortage of housing. So to meet the demand, many homes were built with no thought given as to how long they would last.
But now that the economy is back on track, officials at the Land Ministry want to give house owners a break by extending the life of their homes. They figure that if people were allowed to renovate or rebuild their houses every 10 years instead of once every 30, then the economy would suffer less from people taking advantage of this privilege.
While the West has numerous stone structures, Japanese houses are usually built of wood, therefore rebuilding and upgrading must be done once per generation as a general rule. While some Japanese houses are over 100 years old, the majority are estimated to have a lifetime of 30 to 50 years. There are several factors that contribute to the short lifespan of Japanese houses. Most commonly, wood is used because it's easy to find and inexpensive to maintain. The traditional style of Japanese building involves using timber that's uniform in size and shape which makes it easier to build quality homes with limited resources. Houses are not insulated so they require frequent repainting which reduces their lifespan.
In conclusion, Japanese houses do not last long because they're built of wood, which is prone to decay. Besides, there's no insulation so they require frequent repainting which is also a factor in their short lifespan.
Why are there so many empty houses? There are a variety of complex reasons why Japanese residences become unoccupied. The most apparent reasons are a dropping birthrate and an aging population, but geography is also a factor. Most Japanese cities are far from work, school, and other attractions, which means that it's difficult for anyone except the most ambitious to make a living there.
Another reason people leave their homes behind is because they move away. Many Japanese cities are growing rapidly, so people move to find employment. This is called "karoshi" - working to death. If you cannot find another job, you will have to retire early with no income; this is called "jisho" - going down swinging.
Some homeowners decide not to renovate their houses even if they are lived in. They may be too busy or may believe that someone else will come along someday. A few others may even sell their properties and move somewhere else.
Finally, some houses are simply left empty by their owners. These buildings are often called "desu-zura" - deserted villas. Sometimes this is because the owner died, and the family could not bear to live in the house again. Other times it is because they moved out-of-state and don't feel like coming back anymore. In any case, they leave everything including the toilet seat up!
A house's maximum lifespan without particular care and upkeep is around 200 years. Yes, there are older historical structures, but they have undergone specific upkeep and preventative care that few other buildings receive.
That means that your house can expect to live through at least two generations of people.
The typical house was not built with long-term durability in mind. It was designed to be shipped off to the site where it would be erected with little consideration given to quality construction practices. That means you should not expect your house to last forever if you want it to be worth anything today. Instead, think of it as lasting for around 20 years before needing some major repairs.
There are ways you can extend the life of your house. You can make sure parts of it don't leak, rot, or fracture by including appropriate materials in its design from the beginning. For example, wood that isn't exposed to moisture will last longer than wood that is. You can also maintain your house properly over time to keep damage at a minimum. A well-maintained house has a longer lifespan than one that isn't cared for; simple measures such as cleaning out debris from inside your house on a regular basis will help it last longer.
Cleaning products containing chemicals can cause damage to your house over time.