He will be a key figure in the new management front line being assembled by the BHO chairman and chief executive, John Banks, to give the agency a higher profile. "This will reassure a lot of people we mean business," Banks said.
Young's management partners will be Jonathan Rigby, Lowe's former head of account management who took over as the managing director last month, and a yet-to-be-appointed planning director. Young and Rigby will work jointly on the selection.
Young's brief is to drive up BHO's creative reputation, while acting as a magnet for new talent and new business. He will continue producing ads as well as take charge of BHO's five creative teams.
His hiring is a departure from BHO's traditional practice of having joint creative chiefs - first Chris O'Shea and Ken Hoggins and, more recently, Dave Alexander and Rob Fletcher.
Young's decision to switch from the creatively potent HHCL to BHO, whose clients include Waitrose and Weetabix, will surprise the industry. Young, 40, admitted: "BHO isn't an agency I would ever have imagined working for."
But he added: "I've had lots of job offers for which there were reasons to say no. This time there was every reason to say yes. I could have gone to an agency with a better creative profile. But if all you're going to do is drive a well-oiled creative machine, the most that will be said of you is you didn't screw up. I'd rather have an exciting challenge and get the credit I deserve."
Young has garnered a string of awards since starting at TBWA in 1989. His 13-year association with HHCL was broken only by a short spell as a commercials director and he was lured back as a creative director in 1997. In recent years, he has overseen work for clients including Unilever, COI Communications and Guinness.
Banks said: "I wouldn't have hired Al six years ago as he was too one-dimensional. Now he has a much broader tapestry of work."
Steve Henry, HHCL's creative director, said: "Al has reached a time in his life when he needs to do his own thing. Having done that myself, I understand completely. BHO is a real opportunity to put his stamp on something."