1350 tons of earth excavation for a single-family house

Well, I recalculated it and roughly come to your result without subtracting topsoil. Charging by tons is of course a feast found for the contractor and more is often disposed of.... One could now make a counter calculation with a 60 degree slope angle, etc. and compare these. I would probably do that with the additional amount as well.

To be precise, I come to about 1100 tons if I assume 50m3 of topsoil.

Hello, so with 15.4 x 13.8m (incl. working space) and a height of 3m (topsoil deducted, but you have to include the thickness of the gravel and cleanliness layer and the slab) I come to 637.56m². Calculated with a compaction in the soil of 1.3, that is already 828.828m² and converted to tons with the factor 1.7, you are already at 1409.0076 to. Multiplied by 13.5 Euro/to, that is 19021.60 Euro. I also find the working space very large. Are there reasons for that? However, I would not make any compromises when filling. That should be done properly (imho best with gravel) and properly compacted. If you just throw in any mixture there because you still have it left over, it can settle massively over the next few years. Then your nicely designed outdoor area will sink and you will have to reinvest the money two or three times.

Good evening. Today I fainted. I had earth excavation transported and disposed of. The house is 11.4m X 9.8m plus a workroom about 2m on each side. 25% of the basement is not completely underground. (slight slope) I calculated like this: 111.72 sqm (11.4 * 9.8) X 3.4m (basement height) = 379.85 cubic meters. Plus workroom about 170 cubic meters = about 550 cubic meters. (If I did not miscalculate!) I was once told that earth excavation from cubic meters to tons has a ratio of about 1:1.7, meaning 550 X 1.7 = 935 tons. I am supposed to pay 13.45€ /ton = 12,573€. But the invoice from the civil engineer reads 18,120€!! Over 6,000€ more!!! Does anyone have experience in this matter?

So, with 2m workroom I come to about 730m³, which is probably more realistic. We also have over 600m³ for our approximately 10 x 10m house. Did you also include the gravel under the house in the depth calculation? 13.45 €/t is quite a high price though. Did you not find a cheaper offer or did you have to hire this civil engineer?

2m working space is also quite generous!

Strip foundation? Calculated as well?

PS. 13 euros is cheap, I've already seen 19 euros

You must be confusing calculation by tons or volume.
About 18.-€ per m³ is probably normal (around here).

We already dread thinking about backfilling again. How much material will we need? Does anyone know what that might cost? Our excavation material is not suitable for backfilling, so we had it transported away.

Backfill sand doesn’t cost much (for us), max. €100 per truck (20 tons). The expensive part is often the labor and machine time. If you do it yourself, you can save a few thousand...