Calcs single storey extn + loft widening

Hi John, I'm doing a self build project at home, with good support from the local building control team. They have asked me to check my single storey roof calculations, and beam specs. We are on a very limited budget, so the planning drawings and the building control details have all thus far been prepared by me, but they seem to be acceptable. what would you charge for..... 1) roof load specification 2) beam specification (if at all possible we wish to use wood beams) 3) loft volume calc (its a double hip 2 gable) 4) ongoing tech support if needed. Thanks, Declan