If you're lucky, if you are in my district they want half the foundation excavated.
Just found AI's so much easier to work with, more flexible, much more helpful but there are some good LABC's around.
Use an approved inspector for bg regs. A friend of mine used an AI and spoke to them about planning expiring.
They asked him to dig a trench 1m x 1m then wrote report saying excavations commenced.
Planning dept accepted this as a start!
good luck