Is it a new house or one that's already been gutted or set on fire?.
Where in the country are you? Up here near manchester, 40k will get you a fairly high standard of finish.
I've just finished a 2 bed terrace, gutted back to brick thoughout, already had a small kitchen extention with a shower at the back.
Did damp course, re-render, new kite winder staircase, re-wire, new central heating, new bathroom built upstairs, fully boarded out and skimmed, all new ceilings, new skirts, archs and doors throughout, new kitchen the full size of the extension, fully decorated. New upvc front door and kitchen window. All done to a good standard, took me 3 months on my own, cost 14k