Costs of well foundation - experiences?

I understood the house construction company to mean that the static calculations and load cases are only done once the building permit is available, in order to avoid double efforts. For this, they then require a geotechnical report.

From the perspective of the construction company, this can be done that way. Unexpected additional costs are paid by the builder and the builder has no room for negotiation. For you as the builder, the goal must be to exclude additional costs in case of known difficult soil conditions. In other words, you present the report to the companies in advance and they have to specify the additional costs bindingly during the offer phase. Otherwise, you are buying a pig in a poke. Especially if the budget is rather tight, I would try to avoid additional costs as much as possible here.

I had classified the report as even older, because expired standards are used. Of course, the report can still be used. I just don’t consider the report to be good and am of the opinion that an assessment by another expert might possibly provide better recommendations. What immediately caught my attention: - Building waterproofing according to 18195 was replaced in 2017 by 18533-1 - Homogeneous areas are missing (they replace the soil classes) - Use of excavated soil without declaration analysis (no landfill will accept that) - No description of the foundation, no soil pressures/ bearing resistances etc.

So it may be that this report from 2019 is based on measurements that are older, I don’t know that. I will then turn to another expert. There really are no real neighbors, the only house is two plots away. However, that house was built almost 20 years ago and back then they just massively backfilled and built with a basement. So the whole thing is really not comparable.

I requested a geotechnical report from another expert and received an offer. The offer lists many items, but not everything is planned. Now I wanted to ask here whether this is sufficient or if I should better also commission additional items.

I would be very grateful for an assessment!

Ps: I hope it is okay that the prices are visible, otherwise I will remove them.

You will need the chemical analyses later for the disposal of the excavated material, otherwise the landfill will not accept it or offers the analysis themselves. But you don't need it now, as the analysis for the acceptance of the excavated material must not be too old. The remaining EPs seem upon a quick read to be only necessary for difficult conditions or if additional work is desired. In terms of scope, that looks good for now. You have to know the price, a few years ago I paid half for it. But what can you do.

It certainly can't hurt to already know what costs will come up for disposal. If an unpleasant surprise suddenly appears, you can already plan for the xxx EUR for it and save elsewhere. It would be bad if everything is planned and ordered, the excavator arrives, and the soil test then shows that the disposal costs 25,000 EUR, which is not available.

Mhh... difficult. Unfortunately, I am not really convinced by the offer.

For dynamic probing always billing is done per running meter.
Costs are usually around €40 (€25 drilling + €15 relocation).
Since you already have an idea of how deep they will go, max. 4-5 m, it is cheaper that way.
The expert assumes that after 1.5 m they will reach bedrock (here weathering zone chalk) "at least into load-bearing layers."

The analytical prices are much too high. It can easily be done for €100-150 less. I would also wait with the analysis. I don’t know when it’s supposed to start with you, but the results must not be older than 6 months. On the other hand, from August on the Substitute Construction Material Ordinance (EBV) will come into effect and with it the requirements for the analysis will change.
The soil samples are kept by the experts for a certain time, longer on request. Therefore, first see how the foundation is done and what soil actually arises later that cannot remain on the property. Then see where the soil should go; each landfill has different acceptance values.

The expert fees are also high, but actually I like the billing according to HOAI. The expert report is the important part of the whole measure and sufficient time and thus money should be invested here.

I would maybe get another offer.