[dirtyroboto]

From what I understand, the Japanese body tempreture runs a little below the western body tempreture. This may be because of the large amounts of history the Japanese spent as vegetarians. In the west we have been required to digest meat and meat fats to a larger degree, this leads to a higher metabolic average. The westerner will need to cool down (loose internal heat) before the Japanese, the inverse is also an issue, where in the hot humid summer the westerner can't remove heat as well as the Japanese.
This is just an average observation as many people will fall above and below the standard metabolic for their race.

As for buildings, the main requirments are safety and cost. Japan is very aware of carbon footprints, to the point that, if importing materials to build a house would negate the enviromental (and cost) issues, then a more harmonious build would be used. This would use local or very low carbon materials and would not envisage a structure that would last over 100 years.
If it lasted longer, Hooray!

Glass fiber as I recall, is not easy to recycle. If you demolish a house with GF then most of that get's dropped in the land fill. I am not saying that you can't recycle it, just that the cost involved is greater then producing more glass fiber.