Pre-check bank conditions - Realistic property?

Hello,
Briefly about us:
We are both approaching 40 and have two children together (4 and 5) and are not married.
He is employed in a senior permanent position. She runs a service company with 4 employees and a stable customer base. We always have 7k net fixed available. On top of that comes an annual bonus or additional revenue between 10 and 20k net. We enjoy our life and accordingly have not saved every euro. Liquid equity is at 120k. Another 50k is tied up but can be liquidated within a manageable period, albeit with loss.
Real estate was not our thing, but just now something has come along for us. It costs 430k and the bank values it well. We want to expand the roof (50 to 100k depending on the level).
The goal is to finance the property 100% and cover the rest (incidental costs and expansion) with equity.
What conditions are realistic?
An inquiry has been made with the house bank. I want to be able to assess that.
If information is missing, please let me know.

Regards, Markus

That will strongly depend on the extent to which your expansion is considered value-enhancing. You should plan this professionally and present it to the bank armed with a cost plan.

What kind of fixed interest period were you thinking of? Given your income, a special repayment right would be important to me.

We were thinking of a 10-year fixed interest rate. Cost plan: is a project description with a reliable cost estimate sufficient, or do concrete offers from the individual trades have to be available? Best regards

That depends on the bank. I only described it to my bank and attached a cost estimate from myself. But I also have experience in renovation.

For absolute beginners, it is better and safer for the builder and the bank to bring an experienced architect on board. They often provide a realistic cost estimate.

Other banks sometimes even require cost estimates from specialist companies. I personally would not go along with that.

Too little information could be negative (worse condition), too good might cost you something. I would also inquire with good brokers. They also know what documents their partner banks usually require.