ditch, are they saying you have to pay 5% to the builder of the total price,
and do you need to get more than one quote, or are you so remote that finding one will be hard
if you can find 3, get them quoting "verbally" hopefully you'd get differnt ammounts from each, ask them if they dont mind a bit of conning the govement, tell them its on a grant, and to add 10% to there estimates in writing, send off all 2/3, the grant people will pick the lowest quote, but of course it will still be 10% more than what the builder really wants
so say he wanted £25,000 + 10% would be £2,500= £27,500