can igive my option to a friend and let them buy it instead ?
It depends. Did you sign a contract? If yes, there may well be a clause prohibiting you from selling on. If no, then the builder is not contractually bound to sell to you.
Whatever, you will need to suss out the view and get the agreement of the builder - will they release you from a contract ( if applicable) or allow you to sub your friend?
mf