2011 SAB Award Winning Project - RBC Centre
The 100,000m2, 42-storey RBC Centre built by Cadillac Fairview at Simcoe and Wellington Streets in downtown Toronto is the result of a creative collaboration between the developer and its anchor tenants, RBC and RBC Dexia. The project dispels common misconceptions in the real-estate industry by demonstrating that green buildings with new ideas and advanced environmental technologies need not cost more.
Jury comments: This is a great example of a new sustainably-designed high-rise building [targetting LEED Gold] in the dense core of downtown Toronto. The design carefully utilizes effective sustainable principles. The glass façade provides passive daylighting controlled by light shelves and computerized solar shading. Raised floors allow individual air control and flexibility of interior space for long-term economic savings. Structural columns are kept in board to ensure maximum daylight and tenant flexibility. Overall, the office interior makes a superior working environment for employees, and the project raises the bar for other developers to include sustainable strategies in their buildings. The sphere of influence of such large developments is a promising embrace of sustainability by the private sector.
The goals for the project were clear: a dramatically improved workspace that would be more comfortable for employees, one that was achievable for lower rent, lower fit-out costs and lower ongoing operating costs than traditional office space in the core of the city, and one that would embrace environmental sustainability.
These goals translated into five sustainable design strategies:
• Improved human comfort
• Spatial flexibility
• Energy efficiency
• Water conservation
• Sustainable site development
Daylighting strategies include floor- to- ceiling high-performance glazing, exterior sunshades at the podium levels and computer-controlled articulated, operable light shelves and motorized roller shades on the interior.
Under-floor displacement ventilation provides improved air quality with a single-pass passive stratification approach that minimizes the mixing of stale air with new air supply. Active CO2 monitoring ensures that ventilation air is always fresh.
Storm water is collected for re-use in flushing washroom fixtures, reducing demand on both municipal storm water infrastructure and potable water supply for the building. Low-flow, electronically controlled fixtures further reduce water consumption.
Energy consumption has been reduced through many interdependent strategies, some of which take their cue from early highrises which were much less dependent on fossil fuels. Operable windows and natural daylighting strategies reflect this approach.
One of the major energy management components is the direct connection to the renewable energy source of the Deep Lake Water Cooling district infrastructure; a form of geothermal cooling that provides chilled water to the building and eliminates the need for a dedicated mechanical plant.
Other energy saving measures include: the reduced fan energies and extended free-cooling period that are the result of using an underfloor displacement air delivery system, sensor-controlled artificial lighting and effective daylighting strategies, high-performance curtainwall glazing coupled with exterior sun shading to reduce solar heat gain.
The exposed cast-in-place concrete ceilings increase the effective height of the office spaces to 3.3m and improve the effectiveness of daylight penetration and indirect lighting distribution in the office areas. The thermal mass of the exposed concrete structure tempers both the supply air and the return air.
The greatest waste in traditional office buildings occurs in the reconfiguration of tenant space. RBC Centre addresses these issues in a number of ways. The ability to re-use and re-configure systems reduces demolition waste and extends the life cycle of building components significantly. Modular raised floor panels and the HVAC and electrical systems that work with these panels can be easily relocated and reused.
The underfloor HVAC system in tenant space is not ducted and contains no mechanical equipment, so the reconfiguration of HVAC requires no reworking of systems and creates no waste. Electrical distribution in the floor has been designed for plug-and-play components that can be relocated and reconfigured without an electrician and with no waste.
These strategies combine to make the RBC Centre a flexible workspace that is more comfortable, embraces a commitment to environmental sustainability, and offers tenants lower costs in rent, fit-out and ongoing operating expenses.
RBC CENTRE ENERGY-SAVING MEASURES
Domenic Bonavota, P.Eng., Vice President
Mulvey & Banani International Inc.
Typical office floors are equipped with LiteControl suspended, direct/indirect fluorescent fixtures which are mounted in continuous rows at approximately 4.5m centres and suspended approximately 600mm from slab with a twin suspension system. The fixtures are 347 volt with electronic ballast and two (2) T8 lamps. This configuration achieves an average maintained lighting level of 30 FC when measured 750mm above finished floor and within an open office environment. Furthermore, the fixtures are equipped with integral occupancy sensors which control local areas to ensure artificial illumination is only utilized when areas are occupied. In addition to the occupancy each floor is equipped with daylight sensors (5 to 6 per floor) which control a total of 5 to 6 daylight control zones per floor (2 per exposure i.e 2 for south exposure, 2 for west exposure, 2 for east exposure and 2 for south exposure). This ensures artificial illumination is only utilized when natural daylight is insufficient to achieve the averaged maintained lighting level of 30FC.
Re the RBC Tower, electrical engineers Mulvey & Banani International Inc. have provided the following:
• A GE microprocessor-based lighting control and energy monitoring system controls all lighting in the building. Exterior lights, parkade lighting, ground floor, and typical office floor lighting are controlled by points in the system. Automated controls allow for lighting control of all lighting either on a time schedule, daylight harvesting or personal occupant control basis.
• The above noted microprocessor-based lighting control system complete with fixtures, occupancy sensors and daylight sensors work in conjunction with automated window treatments (fabric blinds) and reflective interior light shelf to respond to changing exterior light conditions based on time of day, season, elevation and window location to facilitate the maximum utilization of daylight and reduce artificial lighting.
- Design Architects Kohn Pedersen Fox Associates PC, New York in collaboration with Sweeny Sterling Finlayson &Co Architects Inc., Toronto
- Architect of Record B+H Architects, Toronto Owner/Developer The Cadillac Fairview Corporation Limited, Toronto
- General Contractor PCL Constructors, Mississauga, ON
- Landscape Architect Strybos Barron King Ltd, Mississauga, ON
- Civil Engineer Schaeffer Consulting Engineers, Concord, ON
- Electrical Engineer Mulvey & Banani International, Toronto
- Mechanical Engineer The Mitchell Partnership Inc, Willowdale, ON
- Structural Engineer Halcrow Yolles, Toronto
- Photos Aka Communication Associates, Inc, Toronto - Shai Gil Photography, Toronto - Tom Arban Photography, Toronto
- LEED Consultant Enermodal
- - Energy intensity: 1105 MJ/m2/year [Includes both base building and process energy]
- Local materials by value: > 20%
- Recycled materials content by value: 7.5%
- Water consumption from municipal source: 342 litres/occupant/year [Includes both base building and process energy]