The Emergency Medical Services Headquarters (EMS HQ) is a critical building for the City of Toronto. It serves Toronto Paramedic Services, Fire Services, and Toronto Police Services. Within this facility, there are three crucial control centres that are operational around the clock, every day of the year.

Through a comprehensive deep energy retrofit project, the EMS HQ has become one of the most energy-efficient buildings in the city. This transformation significantly contributes to the objectives of the TransformTO Net Zero Climate Action Strategy and the City’s goal to eliminate community-wide emissions by 2040.

Currently, buildings stand as the primary source of emissions in Toronto. These emissions stem mainly from the combustion of fossil fuels for heating.

A diagram showing the features of the EMS HQ at Dufferin Street, numbered from 1-7 including building automation system (1), solar PV carport (2), air source heat pumps (3), rooftop unit with heat recovery wheel (4), heat recovery chiller (5), high efficiency boiler (6) and geo-exchange system (7).
Summary of EMS HQ deep retrofit features


Once complete, the EMS HQ building will:

  • Consume 55 per cent less energy
  • Emit 72 per cent fewer greenhouse gas (GHG) emissions
  • Create clean, decentralized electricity locally
  • Employ sustainable energy for heating and cooling
  • Operate at a lower cost
  • Offer easier operation and maintenance
  • Enhance user comfort within the building
  • Function as a more robust critical asset for the City

View the comprehensive energy retrofit details below.



The re-engineered heating and cooling systems optimize the use of renewable energy while dramatically reducing overall energy use and GHG emissions. Key system components comprise:

  • Geo-exchange system: At the heart of this reengineering effort is a geo-exchange (geothermal) system installed beneath the parking lot, which consists of 10 wells drilled to a depth of 850 feet. It relies exclusively on electricity to deliver year-round heating and cooling for the building, significantly minimizing reliance on natural gas and curbing GHG emissions.

Geo-exchange field connection to building showing piping behind a cage underneath the parking lot of EMS HQ.

EMS HQ geo-exchange reversible chiller near piping and enclosed in a metal casing.

  • Heat recovery chiller, ground- and air-source heat pumps: The heat recovery chiller presents a remarkable opportunity for using recovered waste heat to reduce natural gas use and GHG emissions. In both summer and winter, the chiller recovers heat from server rooms, call centres, and the geo-exchange system, and generates usable heat to provide conditioned air to the indoor environment. Air-source heat pumps deliver heating to supplement the chiller, improving heating efficiency and avoiding natural gas use.

Heat recovery and main chiller in EMS HQ underneath a network of piping.

Heat recovery and main chiller outside EMS HQ.

  • High-efficiency boiler: An end-of-life boiler has been replaced with a high-efficiency counterpart, which contributes to the building’s heating processes. This replacement decreases energy usage and GHG emissions, while also serving as a backup heating solution when required.

High-efficiency boiler with a network of piping to the right.

  • Rooftop unit with energy recovery wheel: A new rooftop unit efficiently heats and cools the building spaces. The unit uses an energy recovery wheel to capture heat and humidity from exhaust airflow during the winter, warming the incoming fresh air. In the summer, the energy recovery wheel reduces the cooling load of the incoming air. Consequently, this system reduces natural gas consumption for heating and overall energy consumption needed to maintain a comfortable indoor environment.

Rooftop unit with energy recovery wheel outside EMS HQ.

  • Enhanced Building Automation System: An optimized Building Automation System (BAS) enhances occupant comfort while reducing energy waste. This is achieved through the efficient use of both existing equipment and newly installed systems. Sequencing, setpoints, and scheduling have all been fine-tuned for optimal performance.

Solar PV technology is a reliable approach for generating cost-effective, clean electricity. The solar PV array, situated atop the existing parking garage at the EMS HQ, stands as the City of Toronto’s largest solar PV carport. It will produce 500,000 kWh of clean electricity annually, equivalent to 15 per cent of the HQ’s total usage—equal to the electricity used in 50 single-family homes.