Are the ancillary construction costs of the building provider realistic?

Well, 8,000 for earthworks is, in my opinion, quite okay. A base, so to speak the earthworks on an ideal, flat plot, are always included in the basic price. Our additional services due to the hillside location and some soil removal were 6.5 thousand including tax.

Well, 8000,- for earthworks is in my opinion quite okay. A base, so to speak the earthworks on an ideal, flat plot, are always included in the base price. Our additional services due to the slope and some soil removal were 6.5 thousand including tax.

It really depends a lot. Our neighbor needed a whole 5000, we (50m further) needed 25,000. What earthworks are necessary can only be roughly estimated once the soil survey is available.

After consulting with the local water supplier, they were able to confirm that the laying of the sewage pipes on the property will be at our expense. The pipe is already located at the property boundary, and the handover is at this point. All costs for the connection have already been paid, and there are no additional costs outside the property or for the connection. We therefore have €2500 available for earthworks and laying the pipes on our property.

Drinking water is not laid. The water supplier estimates total costs of €4700 for this property. I would therefore add €3000 here.

We have removed a chimney from the extras, so the fee is waived.

Now to the earthworks. What costs can I expect if there are no poor soil values/complications?
We were unable to get any information from the neighbors, as this is a building gap in an old residential area. The neighboring houses date from the 1970s.
We have a footprint of 12.24m x 6.13m = 75.03m². The house will be pushed in boundary development next to the neighboring house, basically a semi-detached house next to a non-identical house.
The property is basically perfectly level without any special unevenness.

We have just received an offer for the additional costs (30cm included) for the foundation including construction road & preparation for courtyard/driveway and terrace. Additionally, we have to pay about €5500. Our soil is actually quite good, meaning sandy, but at one corner of the house there is about 1.20m of topsoil. At the other corners there is between 0.50cm and 0.60cm of topsoil that needs to be removed. Soil is popular on the property and will be immediately distributed/installed as well. So it doesn't necessarily have to be that expensive. More can be said if you have a soil report. Otherwise, there is a lot of speculation involved!

We couldn’t get any information from the neighbors because it is a building gap in an old residential area. The neighboring houses are from the 70s.

Well, in the past, construction was done quite casually. So, significantly fewer soil surveys and more reliance on construction experience (including the “more is more” approach). Are all the houses probably with basements, too?

The plot is basically perfectly level without any special unevenness.

Without a soil survey, there is no foundation recommendation; meaning any additional costs during earthworks are purely speculative. The ground can also behave quite differently even under one house (there are cases where 3 out of 4 boreholes indicated it was okay, but the last one found an unstable substrate). And this naturally leaves the parties involved a nice loophole in case damages occur. That’s why it’s good that you’re having a soil investigation done. It might show, for example, that one meter has to be replaced due to lack of bearing capacity, and that can really get expensive.

So you pay €5,500 for all the specified earthworks/foundation, or do you pay this amount in addition to the planned amount X for the earthworks?