He said: "The British Property Federation, [former BAA executive] Mike Roberts and others have put the client body back on the map.
I intend to quickly build on this start."
Farrant added that in due course he would appoint a vice-chairman from the private sector to assist in the role of representing all clients.
Farrant said: "My experience in capital investment and regeneration has shown me that one of the best ways of demonstrating the value of working alongside the construction industry is to demonstrate the extent to which these agendas are intrinsically linked."
Peter Rogers, the chairman, of the strategic forum, said the appointment was an important step in enabling the forum to be effective.
He said: "Further progress with the client body is another good news story for the industry."
Farrant has been the chief executive at Barking and Dagenham since May 2000. He is also the chair of the Society of Local Authority Chief Executives.