Thanks for all the responses guys
Had someone out today to quote and the work can be fixed, approx. 2/3 days to complete.
My final concern would be that the builder under specced the steel. The large steels should be 203 X 133 X 30. I know they are 203 X 133 as I have measured, does anyone know how i could check the thickness to see whether he's fitted 203 X 133 X 25 or 203 X 133 X 30.