Residential basement approx. 80 sqm, how expensive?

If I take a standard house from a house provider like Town & Country for example and, because of the hillside location, essentially build the ground floor into the slope. The house remains unchanged, the same size as without the hillside location.

Then, due to the hillside location, I usually need concrete walls for this basement level and certain waterproofing. Why does this justify additional costs of €60,000 compared to a flat construction? The interior fittings are almost the same as in the identical house on level ground (e.g., a bathroom on each floor)...?

If I take, for example, a standard house from a house provider like Town & Country and build the ground floor into the slope because of the hillside location. House unchanged, same size as without the hillside location.

Then I usually need concrete walls for this basement level because of the hillside and certain waterproofing. Why does this justify additional costs of €60,000 compared to a flat construction? The interior fittings are almost the same as in the same house on level ground (e.g. a bathroom on every floor)...?

:D Now it’s getting confusing and illogical. What are you talking about? When planning a basement and discussing costs, you talk about an additional floor and not just about burying an "existing" one or replacing it as a basement.

As I said, I suspect that the OP's questions are a loud thinking process in many directions at the same time – so basically impossible to determine with the naked eye whether it is confused, diffuse, or both ;-)

My suspected actual question is: "My actual building wish is not financially feasible – can it become cheaper if I reallocate part of the living area / living rooms to the basement?"

And the clear answer to that is "no" – a "unfortunately" before that doesn't help at all, the bottom line remains.

The question of a residential basement basically does not need to be asked, because the answer (whether one can or must build a basement) is determined by the plot.

More precisely: the height difference in the building window sets the tone. Somewhere around 120 (+/- 20) cm the calculation tips, whether a basement (i.e., basement walls with space in between) or a non-basement (i.e., slope retaining walls, practically basement walls without space in between) is more efficient.

If the plot says "a lot of slope = basement: yes", then you will "have to" build it. And it will protrude so much out of the ground on one side that you can also use it as living space. The living space costs according to the equipment, so "deepening" the room does not entail a corresponding lowering of the price – not even remotely. Linear shifts generally do not change absolute factors.

If the plot says "little slope = basement: only if desired," the penny-pincher is more likely to omit it.

Above-ground living space does not cost more but only differently: occasional driving rain is not comparable to pressurized groundwater; habitable room windows do not require light courts along with slope securing and drainage; the toilet above sewer level saves the lifting station; the ambient air can hit the wall as icy wind, but it does not store frost nearly as well as the soil; et cetera, etc. And placing electrical conduits on the wall, omitting the screed in the pantry, etc. can also all be done upstairs. Again, the equipment – not the location – determines the price.

I hope it is now clear to the OP why "you save exterior plaster in the ground" is a simplistic calculation. I recommend a budget clarification in the financing section, where you are almost completely spared from my involvement ;-)

If you want to build inexpensively, you can find many tricks here simply by reading : floor plan without bay window, only build the second parking space of the double garage for the workbench and omit the first for the car, front door suitably modest since you rarely get visits from the mayor, roof pitch somewhat oriented so that the non-residential basement fits upwards, manually operated light switches. Then even the attic ladder and shower are each available in senior-friendly versions – and by the way: a pair of golden pants impresses more than a woodgrain sectional door :-)

What is this? The five stages of grief and dying? Phase 1 - Denial?

It costs what is stated in the offer. Period. It is professionally justifiable. Would, could, should is irrelevant.

Either you want it now or not, but don't argue here because you don't like your contracting partner's offer. Switch to Phase 3, negotiation, or better yet to Phase 5, acceptance. Saves time.

Hehe.... Actually, the OP just wanted to know the additional cost between a utility cellar and a residential cellar, but asked the wrong question about the basic costs of a residential cellar. ?