Dorian has been a chartered architect and town planner and a member of the Institute of Historic Building Conservation (IHBC) for more than 25 years.

He is a committee member of the IHBC, the Society for the Protection of Ancient Buildings, the International Committee on Monuments and Sites (ICOMOS), ICOMOS UK and has been a Court member with the Worshipful Company of Chartered Architects, and a Trustee of The Hampstead Garden Suburb Trust.

Dorian has worked for more than 30 years as Historic Buildings and Areas Inspector with English Heritage (now Historic England), responsible for providing advice to all of the London boroughs and both City Councils. He is Chairman of the City Heritage Society. He has worked as a consultant and expert witness for more than 20 years, advising a varied client base on heritage and design matters involving complex, high -profile heritage and new -build projects in design and heritage sensitive locations.

Dorian is a panel member of The John Betjeman Design Award and The City Heritage Awards. He has also been a panel member of The Royal Academy Summer Exhibition Architectural Awards and The Philip Webb Award along with a number of other public sector and commercial design awards schemes. Dorian is a Design Review Panel member of Design; South West, the London Boroughs, Lewisham, Wandsworth and Richmond upon Thames and Islington.