Why do you want to buy a house or vacation house?
I don't know about Scandinavia, but in the US there are a few commonly stated reasons: 1) It shows the world/parents/yourself that you are "grown up" and settled down. "Everyone" does it. You can't raise a kid in a rental! 2) Paying rent "feels" like throwing money away because you don't build equity. 3) There are tax and credit score benefits for owning a home 4) You like to remodel, landscape, or do other work that a rental doesn't allow.
The #1 reason is worthless. You can raise kids and be a grownup in a rental. Everyone doesn't do it, and if they did you still shouldn't do it for that reason alone.
The #2 reason makes sense only if it makes financial sense. For the place you are purchasing, would your annual rent for a similar unit be more than the annual mortgage interest, taxes, and insurance? Are you confident the value of the property will go up? Often, in the US this can be found for a primary residence. It's very rarely true that you'll find a vacation property where your annual rental expenditures for the time at a similar property would exceed the interest, taxes, and insurance.
The #3 reason makes the #2 reason make more sense, but saving $2,000 on taxes/ other interest rates does not make spending $4,000 per year on interest for a mortgage/insurance/ taxes suddenly "worth it" in and of itself.
The #4 reason makes sense, to me, in so far as the unit you buy actually or nearly meets #2, or you so enjoy working that you can find a unit in such bad shape, that within a year or two of work, you can get it to meet #2. But then you are spending money on a hobby, hoping you might break even or make money. I'd suggest being very careful taking on a lot of debt to fund your hobby, unless you can also live in your hobby year round.