Structures: Vancouver’s new tallest building

The 48-storey hotel and residential “One Wall Centre” under construction in Vancouver will become the city’s tallest building. Located at Nelson and Burrard Streets, it sits on the highest ground in the downtown peninsula, opposite the 1950s BC Electric Building which dominated the skyline for many years.

The Wall Centre caused considerable controversy when it was proposed because citizens worried that it might obstruct view corridors and cast shadows. However, architects Busby and Associates designed it as a very slim, elliptical form to minimize its impact.

Because the building is so narrow and tall, it needed a special structural system to meet the region’s seismic standards and to brace it against high wind loading. Glotman Simpson, the structural engineers, designed an outrigger system in which large columns at the side faces are connected to the core with a series of beams ranging from 1.8 metres to 6 metres deep. The beams are reinforced with the largest rebar available of 55 millimetres.

On the penthouse two water towers work as liquid column dampers to further counter lateral forces moving the tower. The water towers do triple service, functioning for fire protection and as a 100,000 gallon heat sink for the heat pumps in the mechanical system. Keen Engineering is the mechanical consultant. The building exceeds energy codes and 30% of its materials will have recycled content. It is being billed as North America’s first “green” high-rise.

Not only is it the highest building in the city, but it also has the deepest excavation, reaching down with five levels of parking, an elevator pit and footings. Also underground, below the landscape plaza, are a ballroom and bus loading area which have a structure on the scale of a large bridge, with 24.4 metre spans and 2-metre deep post-tension beams.