Duncan has practiced in the area of construction law, construction claims, insurance and surety bond litigation since 1979.  He also sits as a private mediator and arbitrator of construction and related disputes.  Duncan is a co-author of the annually published Annotated Construction Lien Act (Thompson Carswell) and the author of Construction Trusts (Thomson Carswell) and Conduct of a Lien (2004, Thomson Carswell).  He is also a frequent speaker at professional and industry conferences. 

He is a Founding Fellow of the Canadian College of Construction Lawyers and has been listed by The Canadian Legal Lexpert Directory as a leading practitioner in the Construction Law area who is “most frequently recommended” to Lexpert’s editors, and as one Lexpert/American Lawyer’s "Leading 500 Lawyers in Canada" in the field of Construction Law in each year since that publication began.  He is certified by the Law Society of Upper Canada as a Specialist in Construction Law, and is an experienced mediator of construction disputes.