That is correct. The thing is while building a new house with these big companies is good and may be cheaper than fixing an old one, the new houses are usually made from cheap material and end up costing in the long run. We recently found a carpenter that could renovate the house for around 10M Yen, so that seems to be the way to go. As the renovation companies add on to every material in the quotation and that really ups the price.

Another reason a lot of these houses are knocked down I think is sometimes the loans can't be paid off and the banks take it over and sell it to the same big companies who intern knock it down and build new cheap homes. Japan loves new.