Foundation tolerances

[Triassic]

I'm writing my schedule of work for my self Build insulated foundations. Can anyone advise on the tolerances for things like the hardcore layer, the blinding layer, the EPS (prior to pouring concret) and finally, the tolerance of the finished power floated concrete?

[MikeSharp01]

Quite a lot there. When we did our Garden room I went for 150mm of Type 1 +/- 10mm across whole surface - done in three layers and whacked each layer, then  a 50mm layer of pea shingle +/-5mm (Quite hard to measure so what I did was lay two 50mm thick boards, one each side and get them level +/- 2mm and used them with a third board, actually one of our I-Joists, to scrape the pea shingle level. Then I created a frame into which the EPS sat and got the top of the frame level +/- 2mm get the EPS up to that and used the top of the frame to level the concrete. Then power floated it. Got most of it, 95%, it +/-2mm but one area was to wet when we floated and I dig a bit of a dip -6mm worst case so I have +2 / -6 as our finished slab (8.5m x 4.5m). Most frame builders want the slab level +/- 5mm. I got the final all flat level (+/-1mm) with the soleplate and some shims (Which you can only get in 1mm increments so I used some commercial plastic sheet at 0.25mm) and cut it up. Having done all that I won't be going to such close tolerances on the main house because the timber moves, shrinks, warps etc, much more than this error so +/- 5mm for me when I do that.