He trained with Colin McWilliam at the Edinburgh College of Art and in the offices of Ian G. Lindsay and Sir Bernard Feilden. He co-founded the firm of Simpson & Brown in 1977 and is now a 'Working Consultant' to the practice. He has worked on conservation and other projects in the UK, India and Burma. He sat on numerous committees, including RCAHMS and Edinburgh World Heritage Trust, and is currently Vice-President of ICOMOSUK. He has written and lectured extensively on the theory and practice of conservation. He edited and annotated a reprint edition of William Adam's 'Vitruvius Scoticus' in 1980.