In the 2/3 of the world where 3/4 of the population lives, wood is threatened by insects, mildew, rot and fungi of all sorts. Aging is NOT a possibility for most wooden housing, as it is quickly lunch for the local parasites. The chemicals to protect from these are even more harmful (Chromated cupric arsenate,phenols etc...). Concrete is both unedible, rot proof and permanent. We want nothing less for our houses.