The math might not work out as poorly as you imagine. I don't know the exact numbers for Sweden, but in Canada (where insurance is required for downpayment less

The math might not work out as poorly as you imagine. I don't know the exact numbers for Sweden, but in Canada (where insurance is required for downpayment less than 20%), putting 5% is actually not a bad move, even if you have 20% down ready, because, similar to the arguments for rent, you can invest the difference and make similar returns to the extra costs for the mortgage.