I fully agree. I guess the intention may have been to make people hurry up buying or building while young.

One of the major political parties here (Centre Party, the agrarian-liberal party) wants people to live outside of the cities. Finnish cities are so small that it's easy to commute from a place with plenty of cheap land and thus it's possible for most people to buy or build a house there if they want to.

Isn't this the same basic principle that drove American suburbia? Expand the outskirts with building houses on bigger plots of land and empty the city centers. It just seemed to have killed city centers in the US.

Granted that Finland has a very different culture (disclaimer: I live in Sweden) and we aren't in the 50s anymore to invest heavily on a car-centric society but incentivising people to move away from city centres can have unpredictable consequences 20-50 years down the line.

I agree, it's better to differentiate based on revenues rather than just age.

In my country, if you're poor and if it's the first house you buy, you can ask a 0% tax loan from the government and use it to pay your stamp duty with it.