Usually the land they are on is appreciating. The houses themselves depreciate.
Sometimes the distinction doesn't matter - but here one of the things we are talking about people knocking down serviceable houses to build new ones. This approach can sometimes even be compelling if land prices rise to a degree completely out of character with the homes originally built on them. See, for example, SF bay and Vancouver.
I seem to have been unclear, when I said "houses are depreciating assets" I meant the structure itself. This is almost always true.
However, the land it is on may well be rising in value enough to counteract the depreciation - so your house + land may well be worth more in 10 years, even though the house itself is probably worth less.
1. Value of land
2. Value of building in perfect order
3. Lost of value of building due to wear/tear etc.
If building/trades costs are rising #2 can rise too while #3 will counteract it, and it depends how much money is put into maintenance and renovations.
See the "almost" in "almost always". You can reduce the depreciation of a depreciating asset by putting money into it, sure, but that doesn't counter the point.
I agree there may be some weird inversions due to a spike in labor and/or material costs - but you wouldn't want to bet on it. The usual case is they are just losing value, and requiring injections of cash periodically.
Has that changed?
I assume you get the actual property, not just the house sitting on it. The land is what japan generally values.