Basement costs - Is the floor slab offset?

Hello everyone,

I would like to get some experience values regarding the costs of basements, as I have now been given additional charges for basements that are far beyond anything I had researched on the internet so far. And we are not talking about fully equipped living basements with floor coverings, underfloor heating, and plastered walls. Of course, insulation and windows, etc., are planned.

For a normal basement: 690 euros/m²
For a crawl space basement: 720 euros/m²

And this is each an additional charge – the general contractor would save on the floor slab. This seems immensely expensive to me. Or are these sky-high prices to still have room for negotiation? What do you think?

Best regards
HB1

How do you come to the conclusion that he is saving on the base plate?

How do you come to the conclusion that he is skipping the base slab?

Isn't that correct? In all sample calculations on the internet, the base slab is always offset.

Well, in 2017 those are just the costs for a basement. I don't find that cheap compared to 2009 but not unusual at the moment. What prices did you research? Did you calculate with the external dimensions of your single-family house?!

I had already received a rough estimate from a general contractor of 100k€ for 100m2 floor area for a basement.

Is that not correct? In all sample calculations on the internet, the base slab is always offset.

At the end of the day, a basement also has a base slab; it’s just included in the price there. Or do you think the basement stands on bare ground?

Which prices have you researched? Did you calculate with the exterior dimensions of your single-family house?!

I mostly found something between 400 and 700 euros per m², depending on the design of course. Then the foundation slab is deducted and then additional costs between 180 and 400 euros per m² result. And that is obviously much, much less than these 690 to 720 euros per m².

The calculation was made in the range between 60 and 75 m² of floor area.

At the end of the day, a basement also has a foundation slab, it just adds to the price there.
Or do you think the basement stands on bare ground?

Yes, you are certainly right. In these sample calculations that you find, the foundation slab is always deducted.