Born in Egypt of Greek origin, Stef started working life with Peter Lind, Fairweather and Holst (now Vinci) before joining Doyle Plc in 1972, initially as Construction Manager before becoming Managing Director in 1975. As principal shareholder since 1976 he developed the business to its current form over a 30 year period and following the MBO now holds a 22% stake in the business.

Stef Stefanou, born in 1941, graduated from London University in 1966.  He now lives in Leeds with his family but is based in Old Hatfield during the week.

Stef maintains a high profile within the industry via his involvement in a number of industry related bodies, including Deputy Chairman of Construct (after 12 years on the Chair 1993-2005), Board Member of SpeCC, the registration scheme, Chairman of Constructionarium and Member of the Construction Skills Network Observatory for the Yorkshire and Humber areas.  He was also founder Board Member of the Movement for Innovation (a government body).

In 2004 he was made a Fellow of the Institution of Civil Engineers.  In 2005 the Dundee International Congress awarded him the Concrete Sector Gold Medal.  In 2007 he was given the OBE for his services to the Construction Industry and also an honorary Doctorate by the University of Westminster.