A net-zero, mass-timber office that sets a new benchmark for low-carbon workplace design in Toronto.

The Ontario Secondary School Teachers’ Federation (OSSTF/FEESO) Headquarters and Multi-Tenant Commercial Building is a landmark mass timber office development in Toronto that sets a new standard for low-carbon workplace design. Overlooking the Don Valley ravine, the building integrates sustainable architecture, renewable energy systems, and biophilic design to create a net-zero operational carbon facility.

Focal Engineering provided energy modelling to support design decisions and performance compliance, working in collaboration with the climate engineering team at Transsolar.

Technical Highlights

– Cross-laminated timber (CLT) floor system with glulam structure-

– Geothermal heating and cooling with heat pumps

– Rooftop photovoltaic array for on-site renewable generation

– Advanced daylight dimming and smart ventilation control

– Green roof and rainwater harvesting for stormwater management

– Targeting LEED Platinum and Net-Zero Carbon performance

The Impact

The OSSTF Headquarters exemplifies how mass timber and low-carbon technologies can deliver both environmental performance and exceptional workplace quality. It stands as one of Toronto’s most advanced net-zero carbon office buildings.

Project Team

Climate Engineer: Transsolar KlimaEngineering

Architect: Moriyama Teshima Architects

Interior Designer: Kasian Architecture

Structural Engineer: Fast + Epp

MEP & LEED Consultant: Introba

Construction: Eastern Construction

Project Management: BTY Group

Energy Modelling: Focal Engineering