pretty much what nwh says
site agent is the bloke who will tell you whats expected
we used to do window glass and frame,internal and external
ALL exterior plastic
ie gutters,fascia,soffit,cladding,storm porches,drainpipes,meter boxes,wall vents etc.
however given the state of the building trade at the moment i would avoid like the plague
bare in mind you will probably be waiting 90 days for payment
and you will be bottom of list if all goes breasts up