Preserving a Heritage House in Châteauguay
Located in Châteauguay, a suburb of Montreal, a new residence by Paul Bernier Architecte involves the renovation of a heritage building from 1814 and the addition of a contemporary extension. Positioned near the river and overlooking Martineau Park, the residence is influenced by its tranquil surroundings and strong presence of vegetation.
Originally a weaving workshop for a religious community, the existing structure was carefully renovated from within to reveal its original framework and materials. The extension was designed with a subdued approach to maintain the prominence of the heritage house. With a narrow width and a low-sloped roof, the addition remains respectful of the historical architecture. Positioned toward the back of the lot, the extension does not obstruct sunlight from reaching the original building.
Paul Bernier renovates a heritage building from 1814 and adds a modern extension | images © Raphaël Thibodeau
paul bernier architecte links the old and new
Architect Paul Bernier links the two volumes of the Châteauguay residence with a glass walkway, ensuring that the original house remains fully visible from the street. This transparent connection highlights the distinction between the two periods of construction. The extension’s exterior, clad in graying cedar and rough concrete, complements the warm gray tones of the original stone. The walkway’s metal cladding echoes the old house’s gray Canadian-style sheet metal roof. The choice of materials ensures durability and allows for a natural patina to develop over time, reinforcing the relationship between past and present.
The house’s integration with the landscape extends beyond its physical connection to the existing structure. A green roof and thoughtful exterior design interact with the site’s natural elements. Large stones are placed between the two sections of the house, forming a channel that directs water toward the river. On the street-facing side, the extension is built on a concrete base, while at the rear, it is elevated on thin columns, reducing its impact on the ground and giving it a floating appearance over the landscape.
a glass walkway connects the old and new structures, maintaining visibility of the heritage house
Vertical openwork boards clad the annex, allowing air and water to pass through while also serving as privacy screens for the covered terrace and select windows. The green roof helps regulate water runoff, contributing to the resilience of the local aquifer network.
In contrast to the original house’s thick walls and deep-set, limited openings, the extension introduces larger windows, creating a bright and airy atmosphere with improved natural ventilation. The bathroom window facing the street is concealed behind an openwork screen for privacy. On the opposite side, the bedroom appears to float above the courtyard, opening onto a terrace that provides an expansive view of the wooded landscape and river through large glass doors. 
a green roof and vertical openwork boards enhance sustainability and privacy
‘De-Renovation’ of the Heritage House
With the renovation of the heritage house in Châteauguay, Paul Bernier Architecte follows an approach that removes rather than adds, restoring original architectural elements that had been concealed over time. Stone walls are exposed by stripping away partitions, and a traditional staircase is centrally positioned, detached from perimeter walls and integrated with the kitchen. The project minimizes built-in interventions, allowing only movable furnishings to make contact with the stone. The same approach is applied to the basement and upper floor, reinforcing a sense of historical authenticity.
Entry is through the original ground-floor entrance on the street side. Inside, the staircase and kitchen counter naturally divide the open-plan space into two zones — one housing the kitchen and the other the living room. The connection to the extension occurs via the glass walkway, where the transition between old and new is immediately perceptible. Stepping onto the walkway momentarily places visitors outside, suspended between two eras. The flooring material shifts from wood to concrete, reinforcing the contrast.
the renovation reveals the heritage house’s original stone walls and structure 
the circulation is designed to create a fluid transition from the historic home to the modern extension
