Hello,
we built last year with the same construction sum of €560,000. I would advise you not to take on too much financial burden. Of course, it is possible to save a considerable amount over a few months, but a repayment period of about 30 years can be a long dry spell. If you have more money set aside, you can make special repayments, but keep in mind that when you have a new house, you often want to treat yourself to something, e.g. new furniture, pictures, curtains, etc. We didn’t even have to borrow half of your amount and now pay back €1,200 monthly. That is very little compared to our net income, but I couldn’t imagine having to think every month about what I can and want to afford. We live in the here and now. If I have something left over, I gladly use it for a special repayment, but we also want to continue living normally. I also think reserves of €30,000 are too little. I would try to save up a cushion in the next few months. What if you separate and have to pay the other out, or the other person has to furnish an apartment? Maybe a wedding is coming up soon? Unpredictable things always happen. Do you currently still live with your parents? In that case, you also lack an overview of what you have to pay monthly for, e.g. insurance, furnishings, maintenance, etc. I have some friends who moved almost directly from their parents into their own house and complained a lot at first about all the living expenses.