We design, fabricate, install, and maintain the mechanical infrastructure that allows complex buildings and facilities to perform as planned.


Our drive for perfection takes many forms. It’s the discipline of careful analysis and verification. It’s our precision and attention to detail. It’s the commitment we make to getting the job exactly right.

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Large-scale construction projects are challenging. We don’t mind that. It’s professionally rewarding to be on time and on budget against difficult odds. Resolving obstacles generates benefits that reach beyond a specific project. We’re always improving. That’s satisfying for us, and brings value to our clients.


We prioritize investment in technology, innovation, recruitment, and education – reducing risk for our clients and delivering livable, high-performing buildings and facilities for the people who own them, work in them, and use them.

Canada's 50 Best Managed Companies 2014 Best Employers in Canada
Michelle Kelson
Josh Kelson
Enzo Primiani


  • Integrity.
  • Expertise.
  • Collaboration.

For more than 70 years Kelson has been a successful, growth-oriented business. We have a reputation for doing what we say we’ll do, and we’re acknowledged by national and international construction companies as high-capability industry leaders. We continue to guide our business according to the principles established by Kelson’s founders – respect for clients, openness to new methods and technologies, and exacting standards for our work.


Our mission is to be exemplary in every aspect of our business – in service to our clients, in the fulfillment of our projects, and in the opportunities we offer our employees.

Our values have remained the same since Kelson was founded:

PeopleWe define results in human terms – safe workplaces, engaged employees, clients well served.
ExcellenceHigh standards bring measurably better outcomes.
InnovationCreative problem solving sets us apart as leaders and raises the bar throughout the industry.
IndependenceResponsible financial management provides stability and reduces risk for our clients.


George Kelson completed his apprenticeship as a plumber, steamfitter, and sheet metal worker in 1922. After working as a skilled tradesman, he recognized the growing need for knowledgeable and efficient businesses. In 1944, with sixty dollars and a tool kit, he decided to go into business for himself.

Working with Beryl Iverson as a partner, Kelson took on work of larger scope and complexity. Gradually the company grew as it gained a reputation for on-time, on-budget, high-calibre plumbing, heating, ventilation, and air-conditioning work. In 1982, with the satisfaction of having achieved a successful career, George Kelson retired. The business became a family tradition as his sons Rod, Larry and Donald, who had been training and preparing for careers in the mechanical contracting industry, took over.

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In the 1980s the firm’s reputation increased further through our work on projects such as the Mount Sinai Research Centre, Scarborough Centenary Hospital and the Allstate Insurance Head Office Building. With success came an increased recognition of the importance of the company to its employees and customers, and Kelson dedicated itself to becoming one of the most dependable, productive, and professional mechanical contracting firms in the Greater Toronto Area.

As the 1990s dawned the company continued to develop and adapt to the marketplace, which allowed it to remain buoyant during the recessionary period. Once the economy improved the company was well positioned to do some of the most challenging work in the industry. Throughout the decade the company completed a number of milestone projects including the York Administrative Centre, Nortel, the Bayview Regional Cancer Clinic, and Apotex Pharmaceutical.

The new millennium brought a number of opportunities and challenges that were both unfamiliar and exciting. We increased the scope of our industrial base with projects like Torpharm, Novex, and Kellogg’s manufacturing facility. We brought to life two of the premiere cultural spaces in Canada – the National Ballet School and the Art Gallery of Ontario.

As the company grew to become the paramount mechanical contractor in Ontario we refined and upgraded our methods of project delivery and improved our customer service, while remaining focused on quality installation. We’ve proven our innovative Design-Build capabilities on a number of large-scale infrastructure projects, including the Toronto South Detention Centre and the New Oakville Hospital.

Throughout Kelson’s history the dedication of our employees and customers has been the engine behind our growth and achievement; we thank you all.