Our headquarters in Hamilton, Ontario is located in the storied Westinghouse HQ, with our second office located in Kincardine, Ontario. Founded in Hamilton, our team represents diverse, creative, tenacious and innovative thinkers, mirroring the energy which surrounds us in this dynamic community. We bring this spirit to a wide range of public and private sector clients across Southern Ontario and beyond.

Renovation to new construction, small community initiatives to multi-million dollar, one-of-a-kind projects, we remain relentlessly focused on achieving our clients’ goals, guided by a commitment to design excellence and sustainable solutions.


Advancing sustainable design intelligence


Transforming design to create a more resilient world


Where we've come from

In 1996, Joanne McCallum and Greg Sather founded mcCallumSather.  Now, with over twenty years of experience, our firm has achieved an impressive record of significant industry firsts. We designed and built the first Zero Carbon building in Ontario and the largest Net Zero facility in Canada, The Joyce Centre for Partnership & Innovation on the Mohawk College Campus. We completed the first LEED Gold Certified building under the CaGBC, the Region of Waterloo EMS Headquarters and built the first facility of its kind in the world, with the largest virtual lab environment, designed to study human communication at McMaster Institute for Music and the Mind.

We recognize the strength of an integrated team. It led to our decision to offer in-house mechanical engineering and interior design services. We did this to facilitate comprehensive service on small renovation projects and improve coordination and system integration on larger projects. LEED Facilitation, Laboratory Design and Heritage Consultation strengthen our service and help us deliver specialized, tailored solutions.

The communities we call home

We design engaging environments that transform communities. Therefore, it’s important to us that we are involved in Hamilton and Kincardine, including many initiatives that strengthen our neighbourhoods and our profession.  Learn More