Compare with Foreign Countries

week 9

     First of all, I will tell you about the affairs of Japanese houses before the affairs of houses of foreign countries. Life span of Japanese houses is about 22 years to 30 years. This figure shows that Japanese houses must be the reconstruction of each generation, that you have to think about the next reconstruction of the house as soon as you finish reconstructing it, and that the value of property of your house which is filled with your love becomes close to zero in only a few 20 years. In sort, your house which you think as property becomes your liability as soon as it completes. Moreover, if the reconstruction of houses is done frequently, incongruous cityscapes are created because the design of each house depend on the fashion of the time in which it is built, and it is no earth-friendly because a large amount of garbage is discharge.





     Next, I will tell you about the affairs of European and American houses. It is said that life span of European and American houses is about 70 years to 140 years. It is more than 4 times as long as that of Japanese houses. For example, in the United Kingdom, it is common to succeed to their houses during three generations. Moreover, it is said that American houses go up in value every year. There are few houses which become liability as soon as it is built like Japanese houses. It is because European and American houses are "sustainable housing" which has an excellent durability and design. So in Japan countless used houses are "vacant houses", whereas in Europe and America people think used houses as valuable houses and acvtively buy and sell it. Other merits of longer life span of housing are to be able to keep harmony cityscapes and to be able to reduce garbage in reconstruction of houses.


      Then what should you do in order to build "sustainable houses" in Japan? We have to think about the cause of shorter life span of Japanese houses in order to know the answer. One of the causes of it is "insulation". Japanese houses have structure to let in a air in order to spend a comfortable time in summer, but recently the building without clearance began to be made in order to shut out the cold in winter. Since then, the moisture in the room is close and is absorbed by the structure such as pillars in the walls, and water droplets are generated by the difference in temperature between indoor and outdoor around the window and on the wall. Water penetrates into the inside of structure of the house. This moisture rots a structure to support the building and encourage the development of mold. As a result, the life span of the house becomes shorter. High thermal insulate system and the system to be able to control the amount of moisture is required in order to prolong the life span of the house.

     By the way, the government also begin to think about the measures against "sustainable houses". In 2008, "200 years housing (200年住宅)" was promoted and in 2009, the "Bill about the Promotion of residential recycling" was submitted. As th above, the whole country is working on "sustainable houses".