Executing an iconic all-glass pavilion entrance to the revitalized Montreal underground retail-dining hotspot at Place Ville Marie was like crafting fine jewelry, says the design-construction team. Submitters note the critical precision required to design, fabricate and build the insulated 630-sq-m glass roof, a record size globally for such a structure.

The 18 roof panels, each 15 m by 2.5 m and weighing up to 5.6 tons, are supported by eight-ply laminated glass beams, with all connectors not seen so the structure appears to float. “There are projects that could be compared, but the main difference is the size of glass and the thickness of the beams, which were never installed like this before,” says Sebastian Keller, project manager for German facade contractor seele GmbH. On a tight and windy site, equipment customized in Germany was used to transport, install and seal panels. 

For roof transparency and lightness, pre-glazed structural brackets are hidden in the wall, with panel bearings and spacers obscured by a perimeter fritting. Canopies at roof ends cantilever up to 4.2 m beyond entrance facades, with supporting 14-ply glass beams.

Stainless steel pockets within beams are “one of the largest [such] pieces we ever laminated into such massive beams,” he says. Extensive analysis confirmed the roof would support winter-weather loads. 

To expedite work, panels made in Europe were stored and brought just in time to the site, which was strengthened to support a mobile crane. A custom-made glass lifter fitted with large suction cups was used, as were enclosures for all-weather sealing. Over 10,000 installation hours were logged without injury or lost-time incidents. 

The project had to work around other upgrades at the PVM office complex and downtown. The team notes budget adds for asbestos abatement, structural reinforcement and scope changes.

The project “creates a new market for oversized glass,” says the team. One judge terms it a “major step forward in this type of construction.”

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