Guidance on the costs of a partial basement

Hello everyone,

I have been reading along in the forum for a while, but now that our plans are becoming more concrete, I have finally registered. Since we have been unsuccessfully searching for a suitable existing property for a long time, we are now also dealing with the topic of building. It is going to be a wooden house. We have had discussions with the bank and the house builder and have even designed a nice house: 1 floor, no basement, 118 sqm. Unfortunately, all the plots we like are on a slope (10% plus). Without a basement, that makes little sense there. However, I am opposed to basements but am now forced to deal with the topic of a partial basement. I have meanwhile understood that without a specific plot, one cannot say anything precise regarding costs, but a very rough orientation on what I have to reckon with at a minimum would be helpful. The house would have a ground area of between 65-70 sqm upstairs. One living room and one bathroom would go into the basement. The rear part (towards the slope) in the basement would then be the technical room and utility room. I find figures of €1100/sqm (including groundwork). Then the partial basement would be €77,000. Is this estimate realistic? Or do I have to expect much more? Thank you very much for your help!

I am afraid the estimate might possibly be too low for a residential basement.

1100€/sqm excluding the foundation slab and earthworks.

We have an offer for the civil engineering works (but not for a residential basement). Just for orientation:

[*]Excavation (703m³) for 140sqm basement (external dimensions): 25,200€
[*]Transport: 7,500€ (but only if the soil is okay)
[*]Basement construction including foundation slab: 84,500€

Certainly, this is only partially comparable due to the different construction method and the slope where excavation is not required. However, when it comes to earthworks, I tend to calculate more generously rather than generously.

Hello Cube,

thanks for your assessment. How much more should I plan for? 1600 €/sqm would be double the amount of your costs. Is a partially finished basement really that much more expensive? That would be 112,000 euros for 70 sqm of basement (of which 20-25 sqm is living space). That would certainly be very ambitious.
More slope probably also needs special support again, which likely won't make it cheaper if I look for more incline, because then the excavation volume decreases, correct?
Thanks and best regards!

For the above-ground sqm you can calculate 2000 EUR. For the bathroom and the living space in the basement as well. Why should finished living space underground be cheaper than above ground? Now it naturally depends on the remaining sqm in the basement level. But with partly living space and technical rooms in the basement, this will be within the thermal envelope. Underfloor heating, nice fittings (flooring etc), expensive windows etc are of course omitted. So roughly calculate for this part of the basement 1600 - 1800 EUR per sqm. Excavation with removal and disposal will then be added. As an example calculation I would therefore assume the following: 25 sqm finished as living space (is that really enough? Bathroom + 1 room + hallway) = 25*2000=50k 45 sqm unfinished (basement room, storage, technical) = 45*1600=72k So total for the basement around 120k + excavation, disposal, removal of soil For 70k you will in my opinion get at most a pure utility basement We build like this by the way. So on a slope with a living basement + 1 storey on top

Thank you both for the quick help! Now I have a good orientation!