Ok then here are the numbers. Net household income 6700 euros. Apart from the "normal" expenses (insurance, streaming, mobile phone, living costs) only the installment of 687 (at 2.6% and 5% repayment) euros for the house. The house value was estimated at 250,000. It is a small house in an affordable area (land value 50 euros per square meter), hence also 1400 sqm of land. The house is very small (currently 80 sqm living space), hence the desire for expansion. It is intended to serve as the main residence for my wife and me in a few years and therefore the desire for a little more space. The other house, currently the main residence, has already been transferred to our offspring. As I said, I am only interested as a layperson in finding hopefully the best financing option. Preferably in one loan, but maybe it doesn't make sense to refinance with the current conditions or there is some other reason against it. I hope this information is sufficient...