Conversion of office space into residential units and vertical extension

TRANSFORMING THE EXISTING STRUCTURE I Built in the 1950s, the original building housed former CNRS offices. It features architectural qualities typical of its era, notably generously proportioned openings and a simplicity of form, with the rational expression of its structures evident on the façade. The project proposes to refine this existing architecture to make it more compelling. The interventions are designed to highlight the qualities of what is already there and to give the building a more legible and contemporary expression.

WOODEN EXTENSION I The building’s extension rises two stories and is distinguished by the use of wood in both the facade and the structure. By extending the logic of the stepped attics, the project creates a smooth transition between the profiles of the neighboring buildings, establishing a new perspective from Rue de l’Amiral Mouchez. The new facades draw inspiration from the existing structure, featuring large bay windows accentuated by the wood’s molded detailing. Terraced planters complete the design and bridge the gap with the existing building, offering new uses and spaces for greenery.

HOUSING I In the renovated spaces, the structural framework is exposed, new circulation cores are installed, the old staircase is converted into loggias, and various outdoor spaces are created to enhance the livability of the site.

The 17 new units, ranging from one-bedroom to four-bedroom apartments, are designed for maximum functionality: utility rooms are grouped in the central section, featuring ample storage; living areas follow the layout of the facades, with generous windows and some rooms arranged in a row to open up or partition the spaces. These same rooms are complemented by wooden alcoves that allow for diverse uses and bring a domestic scale to the larger spaces. The raised floors follow this same geometry, adding a duplex unit.

MATERIALS I In line with a low-carbon approach, the project prioritizes bio-based materials and makes the most of existing resources through the reuse of materials both on-site and off-site: by installing wood fiber insulation; exterior oak joinery for the new window frames; wood in a MOB structure and CLT floors for the addition; wood cladding on this new volume; and wood finishes inside the units. Additionally, by reusing various materials such as the stone paving from the old staircase and by highlighting the facing stone discovered on the street-facing facade during construction.

RESILIENT SPACES I The units retain the existing concrete beams and columns. Exposing this framework also allows for future renovations with a clear understanding of the structures. Flexibility is further enhanced by the design of the spaces, where apart from the circulation core and a few isolated floor openings all partitions between units are constructed using SAD partitions, and the floors are finished with dry screeds; the spaces on the addition feature a fairly open layout with only a wooden partition in the central section. All of these elements ensure the building’s resilience and may allow it to serve many more purposes in the future.” - PLURIEL[LES] ARCHITECTES, project management