The Ontario Secondary School Teachers’ Federation (OSSTF) Headquarters and Multi-Tenant Commercial Building has been recognized with an award for its sustainable design and innovative features. This 3-storey, mass timber project integrates commercial opportunities with the relocation and revitalization of the OSSTF’s office center in Toronto. The building is designed to be highly sustainable, aiming for LEED Platinum certification and high-energy performance levels. It utilizes cross laminated timber (CLT) floor slabs and glue laminated timber (GLT) beams and columns, sourced nationally where possible. The building promotes health and wellness with features such as generous structural bays for natural daylighting, a fresh air strategy, large overhangs to reduce solar heat gain, and geothermal heating. It also incorporates sustainable practices such as rainwater harvesting, green roofs, rooftop solar panels, and automated daylight dimming controls. The building has achieved significant reductions in energy consumption and greenhouse gas emissions. The design also includes the restoration and stabilization of the Don Valley ravine edge, creating a connection to nature for building occupants. The building’s commitment to sustainability and innovation has earned it an award for its contribution to the field of architecture.