Inexperienced home maker here so please bear with me. Local carpenter (not used before) is supplying (Howdens) doors and hanging them for us, along with a couple of other small jobs. Total cost approx £1500, he has asked for £1000 as a deposit which he will order the doors with. When I read online about deposits it all says 20% is about average, obviously this is way above it but to me it makes sense that we'd have to pay for the materials up front, I think!?