Succeeding with sustainability and human wellness in tandem

The office building at One York Street in downtown Toronto is part of a 200,000m² mixed-use development along the central waterfront in the new South Core of Toronto. One York is Toronto’s highest-scoring LEED Core+Shell certified office project to date – achieving Platinum certification at 89 points.

By Dermot Sweeny

Situated between Union Station and Lake Ontario, it occupies two-thirds of an entire city block at the foot of York Street between Lakeshore Boulevard and Harbour Street. The 35-storey office tower is one of three towers [two are residential] rising from a three-storey retail podium. The fourth floor of the podium provides public roof garden access, a shared food court and a significant health/fitness centre. Together, all connected components create a unique metropolis-like complex inspired by the Waldorf Astoria in New York City.

From the outset, the project team was committed to creating a high-performance LEED Core+Shell Platinum building with both sustainability and human wellbeing as design drivers. One York is within a five minute indoor walk to Toronto’s biggest mobility hub, Union Station, and is directly connected to the extensive revitalized Waterfront and a short walk to more than 35,000 residences.

To encourage occupants to use active forms of transportation to and from work, the development includes secure storage for 270 bicycles, and provides end of trip shower and change facilities for cyclists. While at work, building occupants have access to a podium-level landscaped terrace which is used for lunch, relaxation and social events. In addition, the developer negotiated with the City to earmark significant portions of their Section 37 contribution towards the removal of the nearby Gardiner Expressway off ramp, and to create an at-grade neighbourhood park in its place. This will transform York Street from vehicular gridlock to a pedestrian gateway, a true city-building gesture that better connects the city to the Waterfront.

Taking cues from past successes, the base building features large, cantilevered floor plates that allow for greater light penetration, unobstructed views, and provides an uninterrupted, column-free perimeter. When clad with a floor-to-ceiling high-performance glass curtain wall, the design maximizes incoming natural daylight while minimizing solar heat gain. Daylight sensors and solar shades maximize the use of natural light, reduce artificial light and, combined with indirect/direct artificial lights, minimize glare – increasing comfort while reducing energy consumption.

One York is using the latest state-of-the-art raised floor system to provide unparalleled flexibility of access to voice, data and power cabling. The flexibility and ease of reconfiguration reduces initial installation, furniture and churn by up to 50%. The underfloor pressurized plenum is supplied with conditioned air evenly throughout the floor, allowing tenants to install diffusers wherever they are needed. The diffusers can be automated or manually-adjustable to regulate air flow and temperature. Occupants have full control over their own microclimate. The air returns to a central air handling unit at ceiling level. This natural stratification ensures that the clean, conditioned and fresh air is always accessible to each occupant.

Along with 150 other buildings in the downtown core, One York Street is connected to the Enwave Deep Water Cooling system. To further reduce the demand for electric power off site, an extensive array of photovoltaic modules are located on the roof of the commercial tower. The PV installation is projected to produce approximately 86,000 kWh of energy annually.

Two large rainwater collection cisterns installed at One York contribute to a reduction in potable water consumption of over five million litres annually. These cisterns are a major component of the stormwater management system, relieving pressure on Toronto’s aging stormwater infrastructure, and reducing runoff pollution that adversely affects natural water sources. The collected rainwater supplies water for toilets and urinals as well as the drip irrigation system serving the water-efficient landscaping located on the ground and podium levels.

Solving for the two interrelated concepts of sustainability and human wellbeing at One York meant maximizing access to fresh air, natural light, allowing personal control of one’s microclimate, and encouraging active transportation modes, all the while minimizing capital and operational costs, adverse environmental impacts and unnecessary resource consumption. One York is an elegant demonstration of how this can be done successfully.

Dermot Sweeny is an architect and president of Sweeny &Co Architects Inc.

Project Credits
Owner/Developer Menkes Developments
Architect Sweeny &Co Architects Inc.
Structural Engineer Stephenson Engineering Ltd.
Mechanical Engineer The Mitchell Partnership
Electrical Engineer and Lighting Designer Mulvey & Banani International [Commercial]
LEED Consultant Green Reason
Landscape Architect NAK Design Strategies
Photos Doublespace Photography

Project Performance
Energy intensity [building and process energy] = 171.4 kWh/m2/year
Reduction in energy intensity relative to reference building = 46% [For Core and Shell with allowance for tenant consumption, and net of contribution from PV array]
Potable water consumption = 2,362 L/occupant/year
Reduction in potable water consumption relative to reference building = 60%
Reclaimed and recycled material content by value = 15%
Regional materials [as defined by LEED] = 33%
Construction waste diverted from landfill = 88%