Okay so we haven't been on site long but until today all had been travelling well. Excavation for cut/fill, piering, internal plumbing and slab laid all without complications.
Today the plumber is back on site to do the external plumbing and has apparently hit rock.
My SS called me straight away to break the news and to find out it there is anything in our contract for rock. In a nutshell the answer is no, there is no provision, only a clause that states there is no provision for rock and if rock excavation and removal is required it will be at our cost.
I was so surprised to find rock now, and actually so was our SS, he hasn't hit any rock on any other site in our estate. I guess we are the unluckly ones.
He has asked me to got out today at lunchtime and see what it is and how much there is. I have a gut feeling it my be down the side of the house that my neighbour has already built on and could be from that but I really don't know. For now, just hoping and praying it's actually not that much at all (although would they bother to tell you if it was only minimal).