House construction planning process! When to make an appointment with the bank?

Huh, you yourself write that you are going to the bank and want to take more money.

(btw: does it only seem to me that the summer slump is filled with strange financial requests?)

There is simply too little information available to write back to you concretely, or rather, there are no clear statements about monthly income, equity, house size, standard, and value of the land. That would at least be a start. Also, despite turnkey (presumably) in the price of your general contractor, many things are not included in the house price. In other words, the entire ancillary construction costs and a few other small things that add up are missing. My guess is that you have dealt far too little with the whole topic to know what is financially coming your way. How is your building feeling, would you get away with a salary of 320k€?

Yes, you are right. We are still at the beginning of the planning and need to properly inform ourselves. Together we have about 4000 euros net. The house should be about 135 sqm (currently being created, floor plan). We are still planning the equity. Probably 60k, of which we want to keep 30k as equity for the bank and 30k for additional construction costs. The plot has a value of about 50k.

As you nicely said, we are just at the beginning and are informing ourselves accordingly for now. The plot was basically bequeathed to me by my parents and that’s why the idea came up quite short-term or spontaneously.

Let's summarize
- 4k€ monthly income (is that monthly or have you included bonuses and holiday/Christmas pay? Only the monthly incoming money counts for the loan amount).
- Equity is therefore the land and the 30k€, totaling 80k€. The rest does not interest the bank if it is not shown as equity.
- From experience over the last 2 years, 2k€ per sqm of living space is a good value for a realistic calculation.

That would be 270k€ for the house and everything on the construction side. Let's keep the 30k€ additional construction costs. However, things like purchase incidental costs (notary/land registry) are not included here.

That would first be 300k€ without outdoor facilities, garage/carport, painter, floors, lamps, kitchen, furnishings, etc.

Ready for occupancy where everything is finished, you would probably be at 365k€. That means 365k - 30k, a loan of 335k€. That makes a loan-to-value ratio of just over 90%. With that, you can calculate your rate including approx. 400€ monthly additional house costs in any common construction financing calculator = burden from the house