In reply to doz generale:
> How difficult is it to fit plasterboard? something a novice can do or do i need to hire someone?
It is VERY EASY stuff to fit, yes a novice can do it. Easy to cut (score with knife along straight edge, then snap/fold). Easy to fix either with plaster board screws (on battens or ceiling joists) or dab and dot adhesive direct onto sound walls. Best to have helper to help handle the boards. On ceiling sometimes recommended to leave small gap between boards that taped and filled to avoid expansion/movement cracks.
You'll probably want a plasterer to skim the boards after. In which case it may be just better to get a plasterer into to render and skim the walls. Cost delta is relatively small, as they tend to want to round jobs up into 1/2 days. Render (hardwall or bonding) is cheap £7 for 25kgs and can be skimmed after ~40 mins.
...all depends on the quality of finish you want.