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FEBRUARY 2015 | 51 Pearl Tower IMAGES COURTESY REGENCY DEVELOPMENTS Pearl Tower by ZUZANNA WODZYNSKA S itting in Oliver, a neighbourhood located to the west of downtown Edmonton, the Pearl Tower is a landmark building that rises high in the city's skyline. The site was originally home to three mid-1900s buildings, however, time had taken its toll on the structures. In 2008, Regency Developments, the owner/ developer of the Pearl project, set in motion plans for a new high-rise that would set a precedent and help shape downtown Edmonton. "In the beginning the site had zoning for two 12-storey high-rises to sit side by side, but we wanted to look at other ways to best utilize the space and make the most impact," says Raj Dhunna, COO at Regency Developments. And so Regency decided to turn the site on its side and propose a 35-storey tower unlike anything Edmonton had seen before. With the city council on board, the project was approved, but more changes were ahead. "It became such a popular building that we ended up going to our structural engineer to explore the idea of add- ing another storey," says Dhunna. The 35-storey building soon became 36. This demand also led Regency to increase suite sizes, which meant a decrease in the number of units from 174 to 128, making Pearl an even more exclusive residential address. While a number of towers cluster along the north side of the meandering North Saskatchewan River, it is not only the size of the building but the Pearl's dynamic sculptural design that makes it truly stand out from the crowd. "The north top-of-bank river valley is lined with building upon building of similar height and underwhelming expression of design," points out Brad Kennedy, lead architect of Brinsmead Kennedy Architecture. "We introduced the idea of creating a new sculpture in that lineup: a building that did not have a backside, respected the view corridors of its neighbours and introduced a publicly accessible pocket-park along Jasper Ave." For Regency, a stucco building just wouldn't do, so the team began looking at a hybrid curtain wall system. Eventually, it was decided that a true curtain wall system would be in keeping with the con- temporary design of the building, allow- ing for clean lines and floor-to-ceiling glass that would invite natural light to penetrate deep into the building. In doing so the Pearl became the first true curtain wall building in Edmonton. Another focus for Regency and the team was to ensure the Pearl Tower was designed with sustainability in mind and is LEED Silver shadowed. "The build- ing envelope utilizes high-performance panels with triple glazed units to help improve energy efficiency as well as operable windows to allow fresh air into the units," explains Nick Trovato, build- ing envelope consultant from Read Jones Christoffersen Ltd. The glazing was constructed in panels in an interior, environmentally- controlled setting. The unitized con- struction helped improve the overall quality of the system, and the preas- sembled panels were delivered to the site to be lifted into place. Construction on this scale is not without its challenges. "The radical shift between a rectangular grid seven- storey underground parkade, the com- mercial and amenities space, and then the oval residential tower required three layers of transfer beams," says Alaa Elwi, structural engineer on the project from Protostatix Engineering Consultants Inc. "These layered trans- fer beams shift the shear walls and col- umn arrangements around, all while maintaining seismic and lateral load resisting system integrity." Another challenge was the shift of architectural arrangement every few floors. Elwi's team had to maintain col- umn continuity in the tower while pro- viding a functional space. The shifting of the floor plate cutback required no less than 12 radically different floor plates. "Continuous monitoring of the geom- etry, the quality control of the materials by the construction team and the con- tinuous site review played a crucial role in completing the tower successfully," states Elwi. Inside, the building features a num- ber of sustainable and high-tech compo- nents to ensure the Pearl Tower meets the needs of its occupants today and well into the future. Each suite has built in speakers, sprinkler heads have been dropped from the ceiling for esthetics and an iPad system connects from the units to the security feed and the main entrance below to allow residents complete control of who has access to the building. In addi- tion, the Pearl features three of the fastest residential elevators in Edmonton that move at one-storey per second. This sustainability element spreads to the outside where there is an irriga- tion system that uses potable water and a very large drainage tank in one of the parkades. When it came to the landscaping, the Pearl's location, which fronts onto the busy Jasper Avenue, created a unique opportunity for Regency to provide a publicly accessible open space that serves as a mid-block break in the street grid. This space facilitates pedestrian access from Jasper Ave southward to Victoria Promenade along the top-of-bank.

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