Linked to Montreal via the Champlain Bridge, which opened in 1962, Nuns’ Island is a time capsule of mid-century development. The area even boasts a trio of apartment buildings designed by none other than Ludwig Mies van der Rohe. Just a short drive away from one of these towers, Provencher Roy recently completed a retrofit of two of Nuns’ Island’s smaller bridges that addresses another, less praiseworthy remnant of that era: its auto-centric urban planning. Leveraging innovative materials and novel forms, the firm’s reimagined Darwin Bridges successfully shift the dynamic between pedestrian and car.
As the original bridges (which were constructed in the 1960s) approached the end of their material lifespans, a rebuild posed an opportunity for a larger rethink. “The project came with a clear desire not only to replace the infrastructure,” explains Provencher Roy architect Céline Mertenat, “but also to improve a site of major interest, with West Vancouver Park, the St. Lawrence River and 201 Rue Corot by Mies van der Rohe nearby.”
Fairly similar to their predecessors at first glance, the replacement bridges nevertheless reflect new attitudes toward urban circulation. At street level, gently curving walls pinch in toward each road, highlighting the span. Below, these curves now welcome pedestrians and cyclists through a secluded garden hidden within the bridges’ median. It’s a delightful moment of floral richness, but the sloping landscape of young trees and indigenous plants also solves a few infrastructural issues. “The low point of the bridge is a low point for runoff accumulation, so we maximized planting to slow and absorb water,” explains Mertenat.
The pale surface of the concrete — cast with 10 per cent ground-glass pozzolan, a cement replacing recycled glass additive — is marked with vertical grooves and round indentations designed to evoke flowers and fireflies. At night, warm lighting emits from lantern-like LED fixtures along the newly widened underpasses and within the raised steps of the garden itself, a gentle gesture that ensures the garden feels as safe as it is surprising.
- What is GGP? A low-carbon concrete additive made of finely ground glass.
- Who developed it? Researchers at Quebec’s Université de Sherbrooke in collaboration with the Ville de Montréal.
- How was it used in the bridges? It replaced the equivalent of approximately 40,000 kilos of cement, cutting CO2 emissions by 40 tonnes (equal to a car driving 200,000 kilometres).
- Why glass? Recycling the equivalent of 70,000 wine bottles also made for more durable concrete.
- How much more durable? The concrete should last more than 125 years — half a century longer than a typical concrete structure.
Provencher Roy reimagines a pair of Montreal bridges with greenery and glass.