Doug was an architecture student at the Bartlett School of Architecture, University College London (UCL). In 1973 he moved into 12 Tolmers Square with fellow students Nick Wates, Caroline Lwin, Barry Shaw and Pedro George.
In 1975 he joined the London Borough of Camden Architects Department where he worked until 1980. In 1977 he moved to Delancey Street, Camden Town.
In 1982 he obtained an MSc in Advanced Architectural Studies at UCL. From 1980 to 1985 he was a studio tutor at UCL, North London Polytechnic and North East London Polytechnic.
In 1984 He founded his own practice, Lazenby and Smith in Welbeck Street.
In 1987 he moved to the Bahamas to become Senior Architect, then Chief Architect at the Ministry of Works, Bahamas.
In 1996 he joined Arcop Architects, Nassau, Bahamas as an Architect and then partner.