In Longueuil, a new bistro is quietly challenging how we think about workplace amenities. Rather than distancing itself from its corporate context, Siège Social Bistro & Café Social leans into it—reinterpreting the formal language of 1960s and 1970s office design to create a warm, contemporary social destination.

Designed by blanchette archi.design, the project occupies the ground floor of 1111 Saint-Charles Street West and was commissioned by Groupe Mercille, with construction carried out by PR Desjardins. Rather than treating the space as a standalone restaurant, the design extends the architectural DNA of the existing postmodern lobby into a hybrid café–bistro environment.

Spanning approximately 2,300 square feet, the interior is organized into two complementary worlds:

The result is a space that feels anchored in its tertiary context, yet introduces a new culture of use—somewhere between café, bistro, and shared workplace living room.

A strong, disciplined material strategy ties the project together. Matte white square ceramic tiles—used across walls and built-in furniture—reference patterns from the existing lobby, becoming both a visual signature and a spatial organizer. A walnut partition wall, punctuated with glazed openings, softly filters light between the café and bistro, maintaining visual continuity while subtly defining zones.

Material and colour palettes further distinguish the two spaces. The café leans into travertine, mustard tones, and dark woods, while the bistro adopts a more enveloping mix of terracotta, deep greens, light wood, and integrated vegetation. Inspired by modernist interiors of the ’60s and ’70s, these colours are reinterpreted in a restrained, timeless way.

Lighting plays a defining role. A dim-to-warm system allows the bistro’s atmosphere to shift from morning to evening, while a suspended ceiling—referencing office vertical blinds—adds rhythm, depth, and movement. What was once a purely functional office element becomes an experiential spatial feature.

For Groupe Mercille, the project is part of a broader ambition to support the revitalization of a transforming neighbourhood. Open to the public and engaging with the nearby university community, Siège Social is positioned not as a convenience, but as a destination.

By reworking familiar office codes into a contemporary social interior, Siège Social Bistro & Café Social demonstrates how thoughtful design can reshape everyday typologies—creating places that feel both recognizable and entirely new.

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