Quebec theatre saved through glass ‘conserving cocoon’

Faced with severe deterioration of the exterior concrete walls of its building, the Grand Theatre de Quebec opted for an innovative solution: a protective glass casing.

Designed by a consortium that includes architects Lemay and Atelier 21 and engineering consultants WSP, the glass envelope will fully encompass the Quebec City arts complex.

The casing will be integrated with the building in what the architects describe as a "modern, conserving cocoon." The two-metre gap formed by the double facade will be climate-controlled and ventilated, thereby protecting the prefabricated concrete panels.

Construction costs are estimated by the theatre at $18.1 million.

The building envelope repair project is being undertaken on a design-build basis by a team headed by Pomerleau. Its bid was accepted by the theatre’s board of directors after being analyzed by a jury of independent architects and a committee of technical experts.

"It’s a complicated project," said Gaetan Morency, the Grand Theatre’s president and chief executive officer. "The solution was not obvious. This is why we requested a design-build solution."

Other team members are glass design specialists ELEMA and concrete experts SIMCO.

Morency said the theatre first noticed degradation of the building’s concrete panels in 2004. Rusted concrete wall anchors posed an additional problem.

While interim measures were undertaken to protect the building, the theatre ultimately came to the conclusion that "a major intervention" was required.

"Various studies indicated that there was no easy solution," said Morency.

He noted that replacing the large concrete panels would have been a difficult and expensive proposition. The panels are 15 metres high and some of them are affixed to an interior mural.

In 2014, teams were invited to propose solutions. The contract with Pomerleau was signed last July. Plans for the glass envelope got final approval in January.

The theatre was anxious to not only protect the building, within a limited budgetary envelope, but also respect the architecture. The building was designed by Polish-Canadian architect Victor Prus.

"It was crucial to respect Prus’ vision," said Eric Pelletier, senior partner at Lemay.

It was also critical, he said, to preserve the integrity of Jordi Bonet’s mural, sculpted into the interior supporting wall over an area of 1,000 square metres.

The project, which is being financed by the Quebec government, is being monitored by an independent team of professionals retained by the theatre.

Project manager is the Societe quebecoise des infrastructures.

"The chemistry between the teams has been quite good," Morency added.

Site preparation is currently underway. Installation of the glass envelope is scheduled for completion by September 2018. The casing will encompass 5,900 square metres.

Each glass panel is supported by four fasteners. These fasteners in turn are made up of three plaques. An exterior plaque will be connected to a new secondary steel structure.

Glass installer is Vitrerie Laberge Inc.

The theatre is maintaining its daily operations during construction, which Morency said was another factor in the approval of the Pomerleau bid.

"Close co-ordination with the contractor is required to ensure that the construction doesn’t affect our operations," he explained.

Morency said feedback to plans for the new protective shell has been positive, given that the solution respects the original architecture of the building while providing "a modern and contemporary look."

The theatre opened in 1971.