In Norway here, many municipalities do not have property tax. Oslo implemented it recently, but only for property greater than a certain limit (and there is a push, of course, to remove it.) You can tax write-offs on interest from mortgages and also writeoffs and hire interest if you save in a BSU account (Bolig Sparing for Ungdom, or House saving for the young, which only applies to those 18-34.) Also, I think you can get any rental income written off if you rent a room or a basement apartment for 7000 NOK or less.

The fact is now, Oslo is experiencing what people are calling a housing bubble. Prices are also impossible given salaries (given conversion rates, they do not compare to the prices like in NY, for what it is worth.)

All these things tend to point to two directions: a) there is such a drive to own your own home here that it has done something to housing prices and b) they want people be maintain debt. Unlike the US, you can write off credit card and personal loan debt. It's a nice thing to be able to do but I'd presume that encourages a credit boom.