Reflecting on the history and evolution of skyscrapers as we prepare to move into the new Stantec Tower
What do the Metropolitan Life Tower, the Empire State Building, and the Burj Khalifa have in common? They have all been—at one point in time—the tallest tower in the world. For more than the last 100 years, civilization has set their sights on the sky. We revel at the skyline, racing upwards and upwards, trying to touch the clouds.
What is our fixation with height? How high is high enough? Will we ever get there, or will we always push ourselves to pass it?
The official “invention” of the skyscraper came out of Chicago after the devastating fire of 1871 claimed nine square kilometers (5.5 square miles) of the city. The destruction sparked a building boom in the Windy City as Chicagoans seized the opportunity to reimagine their home turf. But by the 1880s, the downtown footprint was seemingly full—or was it?
With nowhere to go but up, architect and engineer William LeBaron Jenney was forced to challenge the status quo for height. For the first time in history, he would use steel in the frame of a “tall building”—the Home Insurance Building. Before this innovation, a building’s weight was supported by its walls, but Jenney’s genius was to “hang” the mass of a building on steel columns. That way, the structure can rise much higher on the same footprint.
The Home Insurance Building was only 10 stories tall, but it would set the stage for skyscrapers around the world. Now our new global headquarters, Stantec Tower in Edmonton, is the tallest example of Jenney’s innovation in western Canada.
Main engineering feats
Tall buildings come with their own special set of design challenges, and Stantec Tower is no exception. It’s height and tight footprint were ambitious but designing a mixed-used tower to include commercial, retail, and residential space was even more demanding. This project was the first chance for many of our team members to come to grips with these question marks—and they relished the challenge.
Foundation: It’s only fitting to start at the bottom with Stantec Tower’s record breaking, three-metre-thick (10 feet) raft slab foundation. At more than 2,800 cubic metres (3,062 cubic yards), it was the largest continuous concrete pour to ever take place in Edmonton and took more than 300 trucks, 4 pumps, and 10 hours to complete.
_q_tweetable:Although working on the tallest tower in western Canada was a great experience, the lasting takeaway for me was the teamwork._q_Because of Stantec Tower’s considerable height—and poor bedrock in Edmonton—the design called for more support in the form of piles. Piles are massive concrete columns set deep into the ground. Stantec Tower’s piles go as far as 80 metres beneath the surface—that’s deeper than the piles of the world’s tallest building, the Burj Khalifa!
Stabilization & outriggers: Whereas foundations give skyscrapers strength, the concrete core walls provide stability. When a tower becomes too tall, conventional concrete core walls are not stiff enough to withstand the wind. So, Stantec Tower implements steel outriggers to help make its height possible, providing support and preventing the top floors from swaying back and forth too much. That way, occupants won’t feel sea sick on a windy day!
So far, there is nothing else like this system in Edmonton—stabilizing these structures is no easy task! Every metre of the material weighs 1,000 kilograms (2,200 pounds). That’s about twice as heavy as a grand piano.
The transfer slab: A transfer slab is set right at Stantec Tower’s 30th floor, 122 metres (400 feet) into the sky—another engineering and construction achievement that’s never been seen in Edmonton before. The two-metre thick transfer slab encases the last of the steel outriggers and allows for flexibility on floorplates that require more or fewer columns.
The transfer slab (also known as a sky raft) caps off the commercial partition of the tower and marks the beginning of construction on the residential portion of the building. The floor will serve as an amenities space for SKY Residences and feature an outdoor patio and lounge area.
An innovative approach
Sustainability: As the downtown core undergoes revitalization, almost all upcoming buildings will have sustainability certifications. Standing tall in the center of them all will be Stantec Tower. Sustainability is not a trend but a central component of design. Stantec is committed to this goal and will be targeting LEED Gold Certification.
Shape: Stantec Tower is a striking mix of two glass rectangles. The bottom is shorter and wider while the top is tall and slender. This design element responds to the mix of office space on the bottom half with condos on the top—not exactly a typical combination in Edmonton. Structurally, residential and office layouts are dramatically different, so a uniform top-to-bottom design, like we traditionally see in Edmonton, was out of the question.
Security: At Stantec, we put people first. This applies broadly across our workplace culture and environment but has a special significance when it comes to the health and safety of our employees. It’s for this reason that Stantec Tower will leverage impressive technology to provide an enhanced security system—a system that will help ensure that time spent at the office is as safe and secure as possible. It will mean some changes to our work space, including new employee access cards and a visitor management system. Here are some security highlights:
- Security concierge greets employees and guests at reception
- Upgraded visitor management system
- Upgraded access cards
- Office alarm system
- Emergency notifications
A job done right and done together
Working on a project of this magnitude alongside several Stantec staff has been incredible. It’s a testament to Stantec’s success, but it’s also a remarkable achievement for the City of Edmonton. Edmonton is our home, and right now we’re amid a dramatic transformation. I’m proud to have been part of such an iconic project in this City.
Although working on the tallest tower in western Canada was a great experience, the lasting takeaway for me was the teamwork. Our team proved we had the ability to collaborate with many team members from several offices in North America. The result? We formed great working relationships and demonstrated the strength, expertise, and diversity of our staff. Now, I chat with colleagues from other Stantec offices almost every single day.
About the AuthorMore Content by Andrew Lischuk