Comment by littlestymaar

Interest rates is the biggest one, but also most fiscal policies related to housing (fiscal exemptions on the revenues coming from rents, the possibility for an individual to deduce the interests of their mortgage from their income taxes, or the absence of taxes on the benefits you make from selling a house).

There are as many such policies as there are countries so not all the above examples necessarily exist in your country (my country — France — having the first and the last one above but not the one about mortgage interests for instance) but they all share the same underlying world model of housing being an “asset you invest on” instead of the “commodity that slowly but surely loses value over time” it really is.