2016-05-01

How Can You Prevent Your House From Collapsing?

Advice

Earthquakes frequently occur in Japan. Last week a large earthquake hit Kumamoto last causing many people to lose their residences. If you are planning to buy a property in Japan or if you already have one, remain cautious of building collapses should an earthquake occur.

In the Hanshin Awaji Earthquake, building collapses caused 96% of deaths. The 71% of houses in Japan constructed after 1981 remain resistant to a level 5 earthquake maximum. However, the earthquake in Kumamoto was over level 7 leaving twelve-thousand houses unlivable. Even if your house does not collapse in the first shake, the danger of collapse still lingers. In such situations, the bathroom serves as the best to protect yourself because compared to the other rooms, the bathroom tends to have less windows and is thus strong.

Moreover, since Japanese houses are not durable for huge earthquakes because their designs include windows on the south side and the only walls on the other sides. Yet people prefer this unbalanced design to allow for plenty of sunshine, but a more balanced configuration of windows and walls better prevents houses from collapsing.

Seismic diagnosis

If you want to know how resistant your house is to earthquakes, you should have a specialist to conduct a seismic diagnosis. If you have a blueprint of the house, the diagnosis costs between 10,000 yen to 20,000 yen.

Renovation

Here are some renovation options that you can do to reinforce and strengthen your house:

・Change Tiled Roof (瓦屋根) to Slate Roof

Slate roof is much lighter than tiled roof, while tiled roof lasts longer than slate roof.

・Install Structural Plywood (構造用合板) and Cross Brace (筋交い) to Walls (approx. avg. 500,000 yen for all four walls)

Structural plywood and cross brace strengthen walls. Structural plywood is made of thin wooden pieces glued together. Cross brace reinforces the structure of walls.

・Foundation repair (approx. 100,000 yen)

This repair involves injecting epoxy resin to cracks on foundation and costs about 100,000 yen.

・One room reinforcement (approx. 700,000~1,000,000 yen)

A house can become much stronger when you reinforce one room. A room’s wall pillar can absorb up to a level 7 earthquake’s pressure. You can escape into the room to save your life.

Seismic retrofitting, including roof, foundation, and walls costs about 1,500,000~2,000,000 yen and can take up to two to three months to complete. Be sure that the configuration of windows and walls are balanced. Depending on the location of your property, you might receive a tax refund for seismic retrofitting after you consult your local government.

If you have any questions or would like to arrange a viewing, please feel free to contact us!