Property financing and subsequent construction project

For what? Just ask an internet search engine. Grundschuld Notar Kosten

Hmm, I assumed €4,900 (2%), the calculator on Focus.de comes to €4,202. So "only" €8,404...

You made a mistake with a decimal point. 2% is with transaction processing

Ah great, thank you very much for the tip, you saved my evening :)

I do have one question though: How much equity should one contribute with the variable loan?

Gladly :-)

Equity: As little as possible and as much as necessary. Ask the bank how much they want for a top condition. Under no circumstances spend it all because you think you’ll save interest that way. You will still need the equity later.

Hello,
so we did it exactly like that. The plot was slightly over 306k, with additional purchase costs (unfortunately still broker fees ...) just under 350k. We financed the plot completely with a variable rate (May 2018: 1.45% at the local Sparkasse) and covered the additional purchase costs from equity, so a mortgage of 306k. Then we took some time to find the right architect and construction company. Just before Christmas we signed the construction contract and are currently in the second financing round. Either it will be with the same bank or the loan will be switched to a fixed rate with the bank providing the financing, then with an assignment of the mortgage.
We can decide freely on repayment until then.
In my opinion, this is the most sensible option because you will have the greatest freedom afterwards. You will definitely not find a construction company or architect by mid-February who are prepared to properly calculate and offer YOU YOUR house. They are currently taking the first customer who shouts HERE, and haste and pressure are very bad advisers. It took us over half a year... So if you don’t want to build only in 10 years, my advice would be to finance variably, calmly find architect/GC/CP and then switch loans. In a reasonable combination of building blocks with the final fixed amount at the end.