Chief executive Mark Tincknell said James' post was likely to be part-time, but his experience of outsourcing and acquisitions would be invaluable.
He said: "This is a step forward for the group and David's experience and knowledge will help us grow further." Current chairman Robert Henry will stay on the board as a non-executive director.
Tincknell said Connaught's core divisions of property services, interior services and facility services had all performed well, and the acquisition of Retail Building Services last November had gone smoothly.
He added that the group was still on the lookout for acquisitions and had been looking at a number of targets.
He said: "We're looking to add related services in the retail, commercial offices and social areas which we already specialise in, or move into a new market."
