Is this secondary construction cost calculation realistic?

By the way, that was our first offer. We will still request an offer from 2-3 other providers.

We would speak with our neighbors beforehand about what kind of earthworks they had to do. That way you might even be able to save the appraisal.

No, what the neighbor has in terms of soil does not replace your soil report. The latter is the guarantee for the stability of your house. On the topic of ancillary construction costs, there is an experience thread in the construction cost forum.

A lot of small stuff is still missing like...

- Construction power connection and rental for the box
- Construction power itself (can quickly go up to 1500€ due to the screed heating program)
- Building application fees
- Non-backfillable soil, so more gravel is necessary
- Many small fees, e.g. for assigning a house number, etc.
- ....

Personally, I would calculate with 10k more in total to avoid too big surprises. If there is money left over, be happy, there will surely be a use for it...

We do not know your building ground; if it is normally grown soil (without peat lens, painter’s sand, and the like) and if you do not have to compensate for any slope, €5000 may be sufficient. But this is really guesswork.

It has now been 3 years; we paid around €3,000 extra for a reinforced base plate + 1.20m soil replacement (50 cm was included in the construction service description).

Is the floor slab also included in the price?

There are still a lot of small things missing like...

- Construction power connection and rental for the box
- Construction power itself (can quickly add up to 1500€ due to the screed heating program
- ....

These items are included in the offer, except for the screed heating.

The base slab is of course included.