Different local authorities charge different amounts for a full plans submission including inspections, but you can work on the basis of about £500. If you are already employing an architect, they would probably charge between six per cent and eight per cent of the cost of the work for preparing working drawings. Or you could try an architectural technologist who may be able to do this work for you for less – to fi nd a local architectural technologist contact The Chartered Institute of Architectural Technologists on 020 7278 2206 or visits www.ciat.org.uk.