Telus Building Final.Qxd
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TELUS WILLIAM FARRELL BUILDING, VANCOUVER BC 1940 ORIGINAL BUILDING, 2001 RENOVATION TYPE: OFFICE BUILDING, 8 STORY OWNERS: BC TELEPHONE ACCOMMODATION SERVICES ARCHITECTS: BUSBY + ASSOCIATES ARCHITECTS STRUCTURAL ENGINEER: READ JONES CHRISTOFFERSEN MECHANICAL ENGINEERS: KEEN ENGINEERING CO. LTD. ELECTRICAL ENGINEERS: REID CROWTHER & PARTNERS LTD. The William Farrell Telus Building is located in the downtown core of Vancouver, British Columbia. This building is located at 49.11 N latitude and 123.10 W longitude. The altitude in Vancouver is 3 meters above sea level. The mean monthly temperature ranges between 3 to 17 degrees Celsius. Vancouver's downtown street grid is skewed at nearly 45 degrees off the north 1 south axis; the William Farrell Telus Building complies with the governing grid of the city. The building holds approximately 500 employees of Telus Corporate, located within the Telus Complex. This building renovation was started in 1997. It opened in 2001-2002, with an updat- ed gross floor area of 12,193 m² to make it a comfortable and sustainable environment. Traditionally, the architect is responsible for initiating environmental awareness in a 2 design. If a design is to be "green" - sustainable elements must be explored at the preliminary stages of the project. Often, the client has to be convinced of the positive environment and finan- cial benefits of constructing a "green" building. In the case of the William Farrell building, the client, Telus Corporate Telecommunications mandated that the renovation to their head office be renovated to make it a sustainable, environmentally conscious design. Considerations to improve the work environment were to be incorporated wherever possible. Telus, as a company, adheres to strict environmental ideologies. Their Environmental Policy enforced by the Telus Investment Recovery operations, in 2001, generated revenue of over 4.8 million and differed over 17,024 metric tons of waste from landfill sites. This was achieved through the sale of used and surplus equipment, the recycling of lead acid and dry cell batteries, the recycling of phone directories, and through the use of video conferencing, which saves on 3 travel costs and CO2 emission fumes reducing greenhouse gases. Their environmental respon- sibility and awareness as a company is unique - Telus is the only North American Telecommunications company to be included in the Dow Jones Sustainability World Index which tracks the leading 10% of sustainable companies in terms of economic, environmental and social Allison Boyes, Kerri Henderson, Andrea Krejcik and Bronwyn Sibbald - 3A Environmental Design criteria. It is part of the communications Environmental Excellence Initiative; a North American group focusing on promoting sustainable environmental practices within the telecommunications industry. Clearly, Telus is a company that is aware of its environmental responsibilities and the economic advantages to building and operating sustainable practices. In the reconstruction of their downtown Vancouver head office, the William Farrell Building was completed by Busby Architects and Associates, Keen Engineering as well as strong participation by Telus' own architectural department. Telus decided that they would keep the build- ing's original infrastructure, however modernize its appearance to reflect the company's vitality and positively contribute to the urban streetscape. The modernization while revitalizing the inte- rior, also provides a safe, efficient, healthy, productive workplace for its employees and customers alike. The building was to be recycled and reused, rather than rebuilt, believing that restorations 4 could create sustainable modern environments, rather than waste energy and material involved in the destruction of the old building. The structure of the existing building was preserved and left essentially unchanged, and a new skin of double-glazed, fritted and frame-less glass was sus- pended off of the existing structure. This groundbreaking system made the William Farrell build- 5 ing the first triple-skinned building in Canada. Generally, double skinned buildings consist of two layers of glass cladding, creating an airspace separation between the two layers ranging between 10" and 30". This airspace, or plenum, acts as insulation for the building deterring extremes in temperature, wind and sound. (Land and Herzog). Sun shading devices are commonly located between the two skins, reducing 6 7 8 Allison Boyes, Kerri Henderson, Andrea Krejcik and Bronwyn Sibbald - 3A Environmental Design the heat gain in the building. Double Skin façades may fall into one of four types: The Buffer Façade, The Extract Air Façade, The Twin-Face Façade and the Hybrid Façade. The building employs the Twin Face Façade as its Double Skin. The Twin Face Façade involves either a curtain wall or mass wall system with an outer skin of single glazing. For this building, a double glazed outer skin envelopes the existing masonry wall along the South and West facades. The entire system is considered to be a triple glazed system due to the double glazed windows on the exterior and the single glazed windows on the existing structure. This makes it Canada's first triple glazed building. The new glazed skin is suspended 900mm above the existing building structure, and runs from the second story up the full height of the building, creating a plenum. The width of the plenum allows for human access between the two skins for both maintenance and cleaning purposes. In the winter, the interstitial space acts to insulate the building, while in the summer the plenum allows for the heat to escape through the vents at the top of the curtain wall. As the hot air rises the cool air falls naturally creating a pressurized air space. This phenomenon is due to the Stack Effect, where the constant upward movement of air lowers the temperature of the existing building's perimeter wall, cooling the interior environment. Operable windows located on both the new exterior skin and on the existing building's masonry 9 façade allow for natural ventilation to enter and cool the workplace. During the summer months, both sets of windows are opened at night to exhaust the entire building, while taking advantage of night cooling. An under-floor plenum is connected to the glazed wall plenum through a flexible duct 10 connected to a forced air filter which pumps the air through the work- spaces providing the main distribu- tion of ventilation to the interior envi- 11 ronment. Each workstation has a control damper, an "in-floor diffuser" connected to the under floor plenum, allowing the individual to regulate the 12 Allison Boyes, Kerri Henderson, Andrea Krejcik and Bronwyn Sibbald - 3A Environmental Design airflow within their interior work environment. The existing windows are double hung and are easy for employees to operate. The exte- rior skin has windows that may be operated utilizing an electronic control from within the 13 office. The plenum, as a result, becomes a 18 temperature regulating façade. Motorized dampers at the top and bottom of the glazed curtain wall are monitored by electronic thermostat sensors, situated at varying points along the mason- ry of the building surface within the interstitial air space. They control the entire ventilation system of the William Farrell Building. The dampers automatically open to vent warm air out at roof level, 14 and take in new fresh air from below when the air temperature in the plenum reaches 17.3 degrees Celsius. During peak daily traffic hours, only the top dampers will open to reduce the amount of pollution entering the building. As the building is located in urban Vancouver, the bot- tom dampers remain closed, eliminating much of the emissions of nearby vehicles. This attention 15 to site and detail creates a healthier work environment for all of its employees. Photovoltaic cells are integrated into the glass banding along the top of spandrel the new glazed skin, which pow- ering the motorized dampers. To reduce heat gain from sunlight, ceramic fritted glass was applied to the exteri- or skin and acts as a solar shade. The por- tions of fritted glass are strategically located to block out the steep sun rays and to control 16 heat gain in the summer, all the while allowing for lower rays to provide maximum light pene- tration into the building and thermal radiation in the winter. The ceramic fritting on the glass has a horizontal pattern that varies in density depending on orientation. Originally the archi- tect's intention was to frit the entire façade. 17 19 20 Allison Boyes, Kerri Henderson, Andrea Krejcik and Bronwyn Sibbald - 3A Environmental Design This would have created an obstructed view of the city, therefore only a portion of the curtain wall was fritted. The fritting also prevents glare while allowing sunlight to penetrate the building. Natural sunlight is maximized through the daylight bounce created by light shelves. These are applied to both the interior and exterior sides of the existing masonry wall and to the interior side 21 of the new glazing system along the South and West facades. These light shelves, made of stretched white cloth, reflect low-level light into the interior spaces in the wintertime, and act as a sunshade to steeper summer rays. Whitewashed concrete ceilings and walls help reflect the inte- rior light evenly throughout the floor. With only half the intended ceramic frit applied to the build- ings' façade, coupled with the light shelves and white walls, the interior environment of the William Farrell Building proved to be very bright. These efforts worked so well that blinds had to be installed after the renovation to further reduce workspace glare. The underlying concrete structure was stripped of its plaster and terra cotta tile treatments, exposing it as much possible. This con- crete is a good material for thermal heat gain and also acts to regulate the interior temperature of the building. While the exposed concrete slab works efficiently as a thermal sink, it also creates 22 an acoustically resonant workspace.