Peter Birnie
Sun
CREDIT: Ward Perrin, Vancouver Sun NOW: An artist’s rendering of Phase 1 of the Bentall 5 project at the corner of Burrard and Dunsmuir downtown. This phase of construction included a new YWCA and underground parkade.
CREDIT: Ward Perrin, Vancouver Sun THEN: An artist’s rendering of Phase 2 of the Bentall 5 project. The construction contract, won by EllisDon, is worth $41 million and is expected to be finished in 2007.
CREDIT: Ward Perrin, Vancouver Sun Project manager John Fleming (left) talks with Eric Spindler on top of Bentall 5. Tenants in north-facing offices will get unobstructed, panoramic views of the Burrard Inlet.
CREDIT: Ward Perrin, Vancouver Sun Project manager John Fleming on top of Bentall 5. The engineering process being used is common in large Asian centres.
Dedicated sidewalk superintendents are run off their feet these days. With so many massive holes in the ground at construction sites all over the region, those who love to peer through gaps in the hoarding to check on the progress of a parade of new towers could be forgiven for missing one of Vancouver‘s most interesting building projects.
After all, the 22-storey Bentall 5 office tower at Burrard and Dunsmuir was finished and opened in October 2002, right?
Not quite. A construction crane has appeared atop Bentall 5 because, in a process known as vertical phasing, the tower is about to start growing again. By April of 2007, Bentall 5 will be 34 storeys tall and what was until recently a wide-open plaza beside the tower will become a restaurant pavilion with plenty of outdoor seating. And it’s all going to happen while the existing tower remains fully functional.
This is Vancouver‘s first example of an engineering oddity that’s increasingly common in construction hotspots like Hong Kong or Shanghai. The architects at Musson Cattell Mackey Partnership were asked to design Bentall 5 so that a functioning office building could grow without disturbing its tenants.
Why not just build the whole thing at once? Bentall Real Estate Services senior vice-president Tony Astles explains that the market for leasing office space has a different life-cycle than that of a construction project, and the two simply didn’t jibe. Bentall then decided the market for hotels looked good, and attention shifted to a mixed-use structure.
“But the process of zoning took longer than the market, the market went down and we were left with a pure office use at that point,” Astles says. With the office market changing so that it became difficult to find an anchor-tenant for 500,000 to 600,000 square feet of office space, he adds, “we had to get a little creative. Putting two buildings on the site was not feasible, so we somewhat facetiously asked if we could build one on top of the other.”
Musson Cattell Mackey Partnership said yes. A researcher was hired to study similar projects around the world and a year was spent calculating the logistics. Bentall sought a development permit for the entire building, but a strike at city hall scuppered some big commitments for leasing space, working in league with the tech meltdown and events of Sept. 11, 2001, to lead Bentall to hold off on Phase 2.
“We had a couple of years of massive negative office absorption,” says Astles, “and boy, were we happy that we had the ability to cap off at 325,000 sq. ft. It saved us considerable economic hardship.”
Now things are bouncing back. Bentall called on the clairvoyance it enjoys due to managing and leasing an extensive portfolio of buildings, saw light at the end of the tunnel and gave the green light for Phase 2 construction of 238,000 additional square feet of Triple-A office space. A raft of new leasing agreements followed: Bell Canada committed to 50,000 sq. ft., the law firm of Fasken Martineau to 73,000 sq. ft. and, most recently, Teck Cominco also signed for 73,000 sq. ft. With another deal in the works, Bentall could see a very healthy 88 per cent of the new space leased long before the project is finished.
The first phase of construction on the site was actually for a new YWCA and underground parkade. EllisDon built that, while Ledcor took over for the construction of the first part of the tower. Now EllisDon is back, winning the $41-million contract for the construction of Phase 2. In Ottawa the construction giant added a 20-storey office building above an existing shopping mall, but had to drill caissons through the mall because the tower hadn’t been planned for.
Bentall’s Astles found an even more complex project in Seattle, where the Swedish Medical Center is adding a seven-storey office building atop a parkade, admissions centre for 13 buildings and two floors of day surgery. On one side is brain and heart surgery, on the other the centre for women and infant care, and the new building had to go up while everything continued to function 24-7.
“We traded notes,” says Astles, adding with a laugh that “they thought ours was a joke because it was so easy.”
Since the full version of Bentall 5 was planned from the start, Bentall and EllisDon were able to work out in minute detail the complicated way that construction could take place with minimal disruption. In close liaison with the city’s planning department, they came up with protocols for everything, from where the construction crane can lift loads to when workers can make noise.
Protective steel awnings along Burrard Street to the existing building’s main entrance are already up. The outdoor plaza has been dismantled and hoarding built so trucks can come off Burrard, unload at the construction staging area and exit through a laneway to Hornby Street. Inside the existing building, two temporary elevators will go into space set aside for a future bank of five upper-floor elevators, allowing workers to ferry materials up to the existing top floor, which is empty. The goal is to have little or no contact between office workers and construction personnel.
Tenants for the first phase signed leases apprising them of the plans for Phase 2. They are guaranteed a safe and professional working environment during the construction and are updated each week (at www.bentall5.com) on the project’s progress.
“This project is not a lot different than having a building go up next to you, with one advantage,” says Astles. “All the excavation, all the dumptrucks, all that extra hammering and drilling and coring and pouring is already finished. We don’t have the dust and noise of other projects.”
There will still be construction noise, of course, but EllisDon must meet specific requirements for decibel levels heard by tenants. Many activities such as hammering and drilling won’t be allowed until after the regular workday is over. The construction firm also had to meet a very special demand when building a protective canopy atop the adjoining YWCA’s roof garden, working only from 7 a.m. to noon because children in the Y’s daycare centre nap from 1 p.m. to 3 p.m.
Multiple levels of redundancy were designed to protect pedestrians from falling debris. While the crane is free to swing through a full 360 degrees, it can only lift loads within a much narrower window above the staging site. An exception will come every couple of weeks when each floor’s wooden forms for pouring concrete are moved up; again, the work will be done outside office hours. On the 24th floor a steel and plywood skirting will extend five metres out around the entire perimeter, while another safety skirt extending even further will follow a few floors below the crane as it rises.
Inside the building, six elevators will continue to operate to all floors currently occupied. Three elevators to the new upper floors will be built, followed by the removal of the two temporary high-rise elevators and their replacement with permanent elevators. The sole freight elevator will have an interesting ride, as a new shaft will rise above it before the elevator is shut down for a month as workers punch through and refit the shaft so the elevator can ride the full height of the new building.
Bentall 5’s HVAC (heating, ventilation and air conditioning) systems will also feature clever adaptations. Fresh air for the current buildings enters at the plaza, while exhaust emerges on the fourth floor. The upper floors will have a separate system of air intake and exhaust, all of it on the new roof. The electrical systems will also be split between old and new.
When it’s all finished in 2007, tenants moving in to north-facing offices with panoramic views of Burrard Inlet will appreciate Bentall’s current words on its website:
“The City of Vancouver is committed to restricting high-rise development at the foot of Burrard Street, so your award-winning view should avoid obstruction.”
And even those who never enter Bentall 5 will benefit, says Astles. The construction staging area at the corner of Burrard and Dunsmuir will itself be transformed by the creation of a stylish restaurant pavilion, scheduled to open by early in 2008.
“There’ll be a 6,000-square-foot restaurant with a mezzanine level,” Astels explains, “and the plaza outside will have a water feature and art and flowers, with lots of outdoor seating. We want this to feel like a pedestrian village.”
Pedestrians will also be pleased to learn that the popular breezeway allowing access between Hornby to Burrard will also be back once construction is completed.
© The Vancouver Sun 2005
