Building plot: Massive fill or better basement with excavation?

We own a sloping plot of land (about 3 m height difference between the street and the later garden level in the basement) and therefore originally wanted to build with a residential basement, as the plot slopes down from the street.

However, today we were on site with an experienced civil engineer who constructs many foundations for prefab houses. He was of the opinion that it would be more sensible and cheaper to build without a basement and instead fill up the terrain by up to 3 m in height using recycled gravel. Even if that would require 500 m³ of gravel.

This could be compacted very well with a roller, and settling would not be a problem. The parking spaces and the front of the house would have to be filled up anyway to reach the entrance.

Otherwise, due to the relatively high sewer line location, we would need a lifting station in the basement, and also the disposal of the excavated material (clay soil, about 200 m³) would be very expensive in the region because there are almost no landfills left (35 €/m²).

Who has experience with these issues? I thought a basement would be rather cheaper and safer for sloping plots than a larger fill?

For landfill prices, better follow the advice of the civil engineer. Pumping station for sh... is also K...e.

Nothing complicated. The question is, when you prop up the house like that, how you can still make use of the outdoor area. The costs for soil disposal are the worst in BW, as far as I know. Thanks to Stuttgart 21. All landfills are full, they charge accordingly high fees. In addition, higher transport costs because it can no longer be dumped at the landfill around the corner.

Hello Thierse

I always tend towards the basement. I'm conservative in that regard.
My house is similar with the plot. Well, 35 euros per m³ of excavation is quite a price. But filling 3 meters with RCL is also not achievable as a special deal.
I have my double garage behind the house at basement level and my terrace on top of the garage. I'm quite satisfied with that.
And if you don't necessarily need a toilet in the basement but only a washbasin and washing machine, a pump sump is more than enough.
Calculate that exactly. Even if the basement becomes a bit more expensive, it would definitely be worth it to me.

Steven

You will hardly see the 500 cubic meters. Expect significantly more. The net volume that you have to pile up *1.3-1.5 is already the volume RCL that is calculated. That is the compaction factor.

Then you will have to remove some of the clay soil anyway, since you cannot build on the topsoil.

Then you also have to consider a 45° slope angle, which means at least another 100-200 cubic meters on top of that.

So, I would have 1900m3 of soil for you if you want.
Disposal here in BW is hell.
Do you have a soil investigation? Then you are quickly at Z0* or Z1.1 and you can double your disposal costs right away.