Architecture studio Lemay have released new visualisations of the glass envelope they are planning to add to architect Victor Prus’ 1971 landmark Grand Theatre in Quebec.

The international firm recently won a design competition for the renovation project, alongside local firm Atelier 21. Together they will revive the Brutalist building, the prefabricated concrete facade of which is facing severe deterioration.

A new protective 5,900sq m (63,500sq ft) glass casing will be integrated with the building to form a double façade. The gap in between the two layers will be climate-controlled and ventilated to protect the structure’s fragile concrete panels and its metal anchors – which have been weakened by repeated freezing and thawing in Quebec’s chilly winters.

Lemay’s design solution was described by the competition organisers as “holistic, delicate, transparent and understated.”

The repair and protection work will take place from Q1 2017 to Q3 2018, during which time the theatre will remain open. The project will cost an estimated CAN$16m (US$11.9m, €11.2m, £9.4m).

Lemay recently won another international competition to redesign the corniches of Morocco’s Casablanca coast and create a 5km-long seaside promenade.