Are secondary construction costs realistic?

Floors Material (own work) 4,000

That corresponds to 28 euros/sqm ... what about adhesive, baseboards, suitable tools, etc.?

The building permit in the simplified procedure (deviation from the development plan) cost us €315 with a comparable construction sum. However, I would easily increase construction electricity/construction water to €2000 if you heat with an air-water heat pump. You also need at least €300-1000 for builder's liability insurance and other insurances.

That corresponds to 28 euros/sqm ... what about adhesive, baseboards, suitable tools, etc.?

That point also immediately struck me, that can't be right.
I would rather estimate around 6000 here, what do you think?

I also do not see the notary fees for the registration of the [Grundschuld]. For example, with €300,000, these are €1,000-2,000.

I also don't see the notary fees for registering the land charge. For example, with €300,000, that is €1,000-2,000.

Oh dear. That will also be included. Thank you! How one is supposed to manage with 10% of the construction costs (as often said here in the forum) is a mystery to me.

If you don't have a basement and a relatively flat plot, then I find the €15,000 for the earthworks questionable. Try to include the earthworks in the construction contract, for example, up to about 80cm. If you have to haul away soil, be sure to get a quote beforehand. Our neighbors were completely ripped off with their 50m3.

Be careful if you want to calculate the volume beforehand. Add about 50% for loosening.