2nd soil test, Worst Soil but less piers?

Hi,
Got the results from the 2nd soil test which says my land is now Class P where it was previously classified as H2. The builder will now need to provide a PH2 slab. Ive got no issues with that, but what i find strange is that on the initial engineering drawings there was 25 concrete piers to the rear half of the house, but on the revised and final drawings there is only 6 concrete piers to the rear of the house. Is it possible to have a stronger slab with less piers???

It entirely depends on the slab design. Beams may have been strengthened to require support less often. I presume you haven't changed your building materials (ie brick to some light weight cladding, conc tile to sheet steel)???

It's impossible to say without seeing it all. Without anything obvious I'd ring the engineer and ask.

Hi we had H1 class and are building single story. Is yours single or double?