Dennis had a long association with the Mirvac Group becoming Director in 1987 and served as Mirvac’s Finance Director until August 2005.  Following his retirement from Mirvac, a joint venture was formed with Robert Hamilton called Broham Pty Limited which provided consultancy services to the property industry. 

Other current board appointments include Hanover Group Ltd, St Hilliers Property Pty Limited and GPT Funds Management Limited.