The expansion of the Bibliothèque L’Octogone offers a contemporary reinterpretation of an iconic building in LaSalle, where architecture becomes at once a vessel of memory, an urban landmark, and a driver of socio-ecological transition. Located at a strategic crossroads, the library is redefined as a major hub for the cultural and social life: a vibrant, inclusive space for sharing, creating, and learning, aligned with the evolving needs of its community. The project is the culmination of years of needs assessments, public consultations, and an architecture competition, all aimed at transforming an existing facility into an open, luminous, and welcoming place connected to its surroundings.

Rather than erasing the singular identity of the original building, the project places it at the heart of the concept. The octagonal volume is preserved, revealed, and extended through the addition of a new floor, increasing the library’s area from 2,645 m² to nearly 4,500 m². This intervention transforms an originally introverted form into a clear, expressive, and enduring gesture, while minimizing the building footprint and maximizing the reuse of the existing structure.

Inspired by LaSalle’s history—from the Lachine Canal to the Fleming windmill, a symbol of freedom—the architecture unfolds through a fluid and ascending sequence. From Dollard Avenue, a generous forecourt leads to a large, permeable central hall, a true interior crossroads linking the city to the park. This central space orients users and organizes circulation toward the various library areas, as well as to rooftop terraces and gardens.

Three lanterns structure both the building and its uses. The Urban Lantern, facing Dollard Avenue and the public square, acts as a cultural showcase open to the neighborhood. The Pastoral Lantern extends toward Parc Félix-Leclerc and the Aqueduct Canal, offering bright reading spaces and a large outdoor terrace. The Community Lantern brings together spaces for gathering and creation, including the café and collaborative areas. Together, they affirm the library’s role as a unifying civic space and a threshold between city and nature.

The theme of comic books, L’Octogone’s signature collection, permeates the architectural experience. Spatial geometry, furnishings, signage, and the sculptural staircase evoke graphic storytelling, transforming the visitor journey into an immersive and playful experience.

From an environmental perspective, the project prioritizes the reuse of existing elements, including the concrete slab and portions of the structure, significantly reducing carbon emissions and construction waste. Currently pursuing LEED Gold certification, the library integrates a high-performance envelope, passive design strategies and efficient mechanical systems. L’Octogone thus embodies a responsible, expressive architecture deeply rooted in its territory.