We are hoping to have a loft conversion and have found an architect that we like. However, I am a bit confused as to what is really required. We dont need planning permission as it is permitted development, but want to get Building Reg permission prior to doing work. The architect has suggested sketch drawings for costing purposes, detailed drawings for submitting to BRegs and then £500 for the structural engineer to do his bit. Has anybody done this recently and had plans drawn up to have work done by builders (not loft conversion companies)? What did you need?