OSSTF Headquarters: A sustainable mass timber workplace

The new Ontario Secondary School Teachers’ Federation (OSSTF) headquarters brings together the relocation and revitalization of OSSTF’s central office alongside commercial tenancy opportunities within a mass timber structure. 

The three-storey building prioritizes health, wellness, and sustainability through abundant natural light, flexibility of use, and state-of-the-art systems. Working closely with design architects Moriyama Teshima, Kasian ensured the interior design was holistically integrated into the architectural vision while centred on the human experience. 

The 40,000-square-foot workplace interior supports OSSTF’s forward-looking goals through a sustainable, health-conscious, and socially attuned environment, blending functionality with timeless sophistication. 

OSSTF’s new offices span four floors and offer westward views of Toronto’s Don Valley. A central full-height atrium provides ease of circulation and is flanked by commercial office space. The south side houses a ground-floor event space and tenant space above. 

The cross-laminated and glue-laminated timber structure is the defining element of the space, complemented by a clean, monochromatic palette that highlights the natural beauty of exposed wood. OSSTF’s identity is subtly referenced through accent colours and custom millwork. 

Finishes evoke the surrounding ravine landscape with subdued tones, soft greys, and neutral carpet tiles. Walnut acoustic slats and absorptive panels reduce noise while adding warmth.  

Shared and arrival spaces, including a custom stone-finish reception desk, offer a bright, welcoming first impression. Offices are arranged around an outer band of workstations for transparency while flexible meeting rooms and distinctive kitchenettes reinforce brand identity and wayfinding. Meeting rooms are outfitted with a variety of furniture types and lighting that offer diverse work settings with a balance of functionality and aesthetic appeal. 

The building’s flexible, accessible infrastructure is concealed beneath elegant finishes, leaving the wooden ceiling exposed. More than just a headquarters, the progressive, future-ready workplace reflects the strength, professionalism, and values of the organization while embracing the warmth and integrity of the building material. 

Photos by Tom Arban