Simpson & Brown is one of the United Kingdom's leading conservation practices, with a growing reputation for high quality new work. James Simpson and Stewart Brown founded the firm in 1977 and in 1998 Andy Davey and John Sanders joined the partnership. In 2006 Addyman Archaeology was integrated with the practice and Tom Addyman became a partner. In 2008 the partnership was joined by Sue Whittle and Jenny Humphreys. The practice currently comprises five partners, two working consultants, eleven associates and a total complement of about forty people.

The office is in Leith - the old port of Edinburgh - in an urban tower house with a 17th century clock tower, which was once the Manse and Steeple of St Ninian's, the parish church of North Leith.