Are you an architect or a designer?

An architect or designer shapes the house: the plans, the look, the planning application, the building regulations drawings. The builder builds it. I do neither - I look after the money that flows between you and everyone else: what the build should cost, whether the quotes are complete, what the contract commits you to, whether each payment request reflects work actually done, and what the final account should settle at. On a well-run self build the three roles sit alongside each other, and mine is the one with no reason to want the price to be anything other than right. If you already have an architect, nothing here replaces them; if you do not, everything on this side of the fence still works, because none of it needs a drawing board.