ᐅ Filling with recycled crushed limestone? Land about 60 cm too low

Hello,

First of all, thank you for this forum! I have read many helpful posts here.
Now to my question:

Our plot is unfortunately about one meter (3 feet) below street level. The house is already designed, and a general contractor (GC) has been selected and contracted. No basement is planned.
Since we don’t want to build too far below street level, the current compromise (which has also been submitted to the building authority / planning permission office) is to raise the plot slightly, still remaining below street level. The neighbors did the same several years ago.
According to the soil survey, we have 20-30 cm (8-12 inches) of topsoil, which obviously needs to be removed.
After that, about 50 cm (20 inches) of fill material must be added (according to the soil report, using RCL 45). A load-bearing slab will then be poured on top.
The footprint of the house, plus 1 meter (3 feet) on each side, is approximately 95 m² (1,022 ft²). According to my calculations, that equals roughly 47.5 m³ (1,677 ft³), which corresponds to about 90 tons (U.S. short tons) of RCL.

My GC is offering me a price of €48 per ton for RCL, including delivery, compaction, etc.

Now for the questions:
- Does it even make sense to raise the fill that high?
- Is the price per ton reasonable? I realize I don’t have many alternatives, but I’m asking out of curiosity.

Thank you and best regards

Hello,
1m3 of recycled concrete material weighs approximately 1470 kg (3240 lbs). There are many combinations; the crucial factor is that it is suitable and tested for the foundation. I pay 40 € for installed recycled aggregate. Don’t you have a soil report? It should indicate which materials are recommended.

Is the 60cm (24 inches) height consistent across the entire property?

If you build up the foundation slab, will you end up with steps leading down to the garden?

Or are you planning to add soil on top as well?

Fairplay-Haus schrieb:

Hello,
so 1m³ (35 cubic feet) of recycled concrete (RC) material weighs about 1470 kilograms (3240 pounds). There are many combinations; what matters is that it is suitable and approved for the foundation. I pay 40 € for installed recycled gravel. Don’t you have a soil report? It should specify which materials are recommended.

Well, the soil report says that RC with a 45mm (1.8 inches) grain size would be suitable. Hence the question.

tomtom79 schrieb:

Is the 60 cm (24 inches) the same across the entire plot?

If you raise the concrete slab, will you have steps down to the garden?

Or do you plan to add soil as well?

For the rest of the garden, I will just add soil normally to level it out. As far as I know, this doesn’t have to be any special material; if needed, it can be topsoil from another construction site.
What really matters is what’s beneath the concrete slab—that cannot be changed. In the garden, I’m not worried if the fill settles over time and I need to add more soil later.