Gregory D. Hersen*

Tel: 416 777 5400 Fax: 1 888 812 2560
*Legal services provided through Gregory D. Hersen Professional Corporation


Greg Hersen is a partner and Chair of Torkin Manes’ Construction Law Group. He has been certified by the Law Society of Ontario as a Specialist in Construction Law since May 2001, and annually recognized since 2017 in The Best Lawyers In Canada© for Construction Law. He has also been Repeatedly Recommended by his peers for Construction Law in the Canadian Legal Lexpert Directory and recognized as a leader in Construction Law in the Lexpert Special Edition on Canada’s Infrastructure lawyers. Greg also holds a Distinguished Peer Review Rating with Martindale-Hubbell. 

Greg provides ongoing strategic advice to public and private sector owners, general contractors, sureties, subcontractors, suppliers and design professionals throughout the life cycle of construction projects. These projects include public infrastructure projects relating to transit systems, bridges, highways, flood management and erosion control, recreational infrastructure, educational and healthcare facilities, and private sector industrial, commercial, residential development and mining projects. 

Greg advises clients on a wide range of construction issues, including claims relating to delay, tender disputes, claims for lien, deficiencies, contract termination and abandonment, extras, negligence, surety bonds and indemnity agreements, COVID-19 damage claims, and breaches of trust. In addition to advocating for his clients before the courts at trial and appellate levels, Greg regularly participates in ADR processes, including negotiation, mediation and arbitration.

As the first lawyer to be appointed to the Canadian Construction Documents Committee (CCDC), Greg participated in the revision and development of standard CCDC construction documents, including Stipulated Price, Civil Works, Construction Management and Design-Build Contracts, for more than a decade. He is proficient in drafting tender documentation, construction contracts and professional service contracts related to construction, and skillfully advises on matters related to contract compliance and Ontario’s Construction Act, including prompt payment and holdback release issues.

Greg is a frequent speaker at construction industry seminars on new developments in construction law, including design/build and construction management contracts and disputes, delay claims, the CCDC family of construction documents, Construction liens and payment bond claims. He has also presented numerous Continuing Legal Education Programs for the Ontario Bar Association, The Law Society of Ontario and the Canadian Bar Association. 

Lexpert Ranked Lawyer 2023



CLSA Fellow

Awards & Recognition

  • The Canadian Legal Lexpert Directory - Repeatedly Recommended, Construction Law
  • The Best Lawyers in Canada© - Construction Law (2017 - present)
  • Charter Fellow of the Construction Lawyers Society of America (CLSA) - Top Construction Lawyers 
  • Martindale-Hubbell - Distinguished Peer Review Rating 


  • The Advocates’ Society
  • Canadian Bar Association - National Construction Law Section Executive, Member-at-Large, 2007-present
  • Trial Law Institute
  • Diversity Law Institute
  • Grand Valley Construction Association
  • Metropolitan Toronto Lawyers Association
  • Ontario Bar Association - Construction Law Section, Past Chair, 2006-2007
  • Ontario Bar Association - Construction Law Section Executive, Member-at-Large, 1996 - 2006
  • Canadian Construction Documents Committee (CCDC), Past Ex-Officio Member – 1999-2007

Community Involvement

  • 2nd Degree Black Belt in Shotokan Karate


  • LL.B., University of Windsor, 1989
  • B.A., University of Western Ontario, 1986


  • Certified by the Law Society of Ontario as a Specialist in Construction Law, 2001 — present
  • Called to the Ontario Bar, 1991