Costs for heating, sanitation, earthworks, wastewater and fresh water

Hello everyone,

we have now received an offer for our house, however starting from the sand slab (no basement) without heating and sanitary installations (we wanted geothermal heating here, which is why the BU had dropped out).
The house has 3 bathrooms: 1 WC with ~2 m², a shower bath with 5 m² and a bath and shower bath with ~8 m²; equipment is robust ;)
The heating is to be a geothermal heating system with deep drilling (costs for the drilling about 7000 T€), 187 m² underfloor heating
The access path to the house is already quite long at ~40 m
The soil report mentions "minor" additional costs for the foundation - one corner has 20 cm too much clay.

I have looked here in the forum and found prices around 50 T€ for probe drilling, sanitary, and underfloor heating - is that realistic?
What should we roughly plan for earthworks and wastewater, etc.? Is the dimension of about 20 T€ realistic?

We were still waiting for feedback from both trades but want to make a rough estimate already.
Thanks and best regards.

We are at 45,000 euros for 125 sqm underfloor heating, brine heat pump, 100m deep drilling, 1 bathtub, 2 showers, 2 sinks, 2 toilets, inlet and outlet water inside the house. Not included are the lines outside the building. And we haven't really gone all out.

I would say the direction is right. In detail, however, only someone who knows the exact situation on site can tell you that. It will be easier for you to spend more than to save larger amounts.

Why is your BU backing out because of a little deep geothermal energy? That wouldn’t be particularly complicated for us now.

He always works with his standard companies - and they only offer gas condensing boilers. However, he gave us a contact. Maybe he is also not interested in the coordination.

It may be that way, but please think about it:

The heating system underfloor heating is identical, the distribution is identical, whether a gas boiler is mounted on the wall or a heat pump is installed, it is irrelevant, the commissioning of a heat pump is usually done by the manufacturer (not the installer) anyway, whether connecting gas or brine... well ok, that is a difference. The piping outside and the drilling is done anyway by the specialist company for drilling. Likewise the permission from the municipality.

Coordination? Pulled out of thin air. Whether the gas connection has to be in place first or the brine, probably makes no difference.

But be that as it may. If he does not want it, he does not want it. But consider the consequences regarding the warranty.

The mentioned amounts may be correct, but you are moving at the lower end in the sample selection.

What worked for 40 with us could also have been had for 28, but that would have become the standard of social housing.

However, one should only commission heating companies with experience in heat pumps for this matter - insofar, I find the behavior of the GUs good that they simply do not let their companies do it.

He also gets the warranty that way - especially with heating, the trade is nicely self-contained.