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Some Natural Concerns About Purchasing Real Estate in Japan

The Building Standards Law and Fire Defense Law

In the 1950s, the Building Standards Law and Fire Defense Law already included regulations on fire protection division, fire doors, fire-resistant structure, and semicombustible and flame-retardant materials. Seventy years of accumulated knowledge contributes to the present versions of these laws.


It should be noted that in laws at the municipal level are sometimes more strict than the Building Standard Law or the Fire Defense Law. The Tokyo Metropolitan Government, for example, has the Tokyo Metropolitan Building Safety Ordinance, but in 2010 introduced a new fire control regulation system that has been revised as necessary.


The Tokyo Metropolitan Government is steadily improving roads and razing and replacing combustible buildings in areas densely packed with wooden structures to ensure safety in disaster and to prevent the reproduction of densely packed wooden areas. For areas that Tokyo’s governor has designated as being at high risk of disaster, the fire resistance of buildings was reinforced.


To Be Continued




Protecting Your Property From Fire

We have to consider fire both by itself and as the outcome of an earthquake. Traditional Japanese buildings are wooden structures with wooden façades. They look quite attractive, but of course they are also quite flammable. Since they are usually built up in densely concentrated neighborhoods, fire engines generally cannot reach them to carry out firefighting and rescue work.


The Tokyo Metropolitan Government conducts surveys every five years to measure the risk of an earthquake at specific city blocks. The risk of collapse of the buildings and fires caused by an earthquake are ranked in five levels as shown in Figure 9.9 below, and each city block is colored based on the scale.


To Be Continued

Protecting Your Property From Earthquakes

It is imperative for structural engineers to learn how to confront the seismic wave of kinetic energy an earthquake releases on buildings. Because of its frequent earthquakes, Japan has established three different types of advanced earthquake-proof structures: earthquake-resistant structures, seismically isolated structures, and controlled-response structures.


Earthquake-resistant structures

No structure is entirely immune to earthquakes. The goal of earthquake-resistant construction is to erect structures that withstand seismic activity better than conventional ones. When built to code, earthquake-resistant structures are designed to withstand the most massive earthquake likely to occur at their location, and also minimize the loss of life.


Earthquake-resistant structures absorb seismic impact through structural elements such as columns, beams and braces. These structural elements must be both strong and elastic—stiff enough to absorb the kinetic energy and also have the right deformation performance.


To Be Continued

Better Regulations From Hard Experience

Although Japan has always experienced earthquakes, the country’s first seismic code was only set down in 1924 after the Great Kanto Earthquake hit the Tokyo area in September 1923. Sixty percent of the city’s structures were damaged in that catastrophe, and it is considered Japan’s second-worst disaster after the Great East Japan earthquake in 2011. The seismic code is typically revised and strengthened whenever large-scale earthquakes rock the country.


The next seismic code went into effect in 1950 when the Building Standards Law was enforced. The law’s goal was to ensure the safety of human lives by preventing building collapses. However, that law only considered the mid-level earthquakes that occur several times during a building’s service life, ignoring the possibility of large-scale quakes.


Five major earthquakes between 1964 and 1978, however, proved that the seismic code was outdated. Based on an analysis of those quakes, a new seismic code was established in 1981. The code took into account damage caused by soil instability and weak major load-bearing parts such as beams and columns. Other factors assessed included structural deformation, unbalanced structural members, and the relative plasticity of the structure.


To Be Continued

Some Natural Concerns About Purchasing Real Estate in Japan

Any practical and honest assessment of investing in Japanese real estate has to factor disasters such as earthquakes and fires into the equation. If this is the reason you’re hesitating to buy property in Japan, you need to know the detailed countermeasures taken here to guard against such disasters so that you can judge any potential investment properly. This chapter covers what those countermeasures are, how they developed, and what you should look for.


Japan is a much safer country in this regard than you think.


When the ground shakes

According to the Meteorological Bureau in Japan, earthquakes hit Japan quite often throughout the year. In fact, on average there are approximately 4700 of them between 3 and 4.9 in magnitude on the Japanese scale, with an additional 140 between 5 and 5.9, 17 between 6 and 6.9, and 3 from 7 to 7.9. Twice in a decade, there are quakes of above 8 in magnitude.


Many people in Japan are desensitized to earthquakes, and if the magnitude is less than 5 their reaction is muted. When an earthquake with an intensity of more than 5 hits, however, people take notice.


To Be Continued