Earthworks costs, hillside house

Hello everyone,

I have reserved this plot, see attachment, and have already received a cost estimate from the construction company. The construction company wants to build a hillside house on the plot, see picture in the attachment. It costs about 18,000 euros more than a house with only a base slab. Additionally, the earthworks were estimated at 40,000 euros, including drainage, additional foundation, etc. Unfortunately, that is a total of 40,000 euros more than originally planned. What do you think about the cost breakdown? Is it really that expensive?

Slope is always more expensive than flat, that's why we built a basement.

The earth has to be excavated, etc. It has to be intercepted, stairs have to be built, etc. The 40000 will probably only cover the roughest work.

I find that quite realistic. We are also building a hillside house and in 2019 we paid about 65k for civil engineering + foundation slab. Additionally, further insulation as well as sealing against the slope + drainage may be necessary. Extra costs for us were about 15k (also depends on whether you are building KfW XX, what the soil report says, etc...). You should ask here again. Also, another buffer is recommended because things can always get more expensive.

PS. For you, it’s not just a house on a foundation slab either. According to the animation, you get a proper basement with earth-contacting walls and that can also drive up costs further.

18,000 more than on flat land can be. The final word is with the structural engineer and the geologist.
More reinforcement
Thicker base slab
WU concrete
Wall on the hillside side executed stronger than on the level
Floor ceiling

Earthworks vary greatly by region. I don't find 40 thousand too much. You can't say exactly

What is still missing is the outdoor area. Every height difference must be compensated, every excavator bucket costs

Do not plan one square meter more than necessary. A "basement" is now possible as full living space.

Attached is also a picture so you can better imagine the extent.

For you, road construction will in future also be at least another 0.8 - 1.2 m higher (see [Kanäle]). Yes, the slope is at least that much more expensive. It’s already good that the [GU] was honest. There are often nasty surprises because of this.