Founded in 1939 by a group of eleven general contracting firms, the OGCA has grown into the largest representative associatio ... n in the construction industry. Our members account for approximately 70% of all of Ontario’s Industrial, Commercial and Institutional projects and for 100% of all Alternative Finance Projects (AFPs). For more than 75 years the OGCA has worked to build Ontario by assisting our members to deliver construction excellence in the Industrial, Commercial and Institutional Sectors. Members include small, medium and large firms representing both union and open-shop contractors. read more