Synapses

Ségoffin, the very first site in the Empreintes call for mixed-use, low-carbon urban projects, has a winner. The Synapses project will be developed by Pitch Immo.

The Empreintes Call for Innovative Urban Projects involves the transformation of 5 sites, including the Ségoffin site, located at the junction of the business district and the town of Courbevoie. The guiding principles are environmental exemplarity, contribution to neighbourhood life, mixed-use programming and technical innovation.

Paris La Défense is determined to encourage the emergence of a new generation of exemplary urban projects and future property developments in the area. By organising the Empreintes consultation process, the business district developer is supporting private operators in the co-construction of quality projects, embodying its raison d'être: to become the world's first post-carbon business district.

The Ségoffin site

At the heart of a highly mixed neighbourhood, the Ségoffin site is located inside the Boulevard Patrick-Devedjian. It is bounded by the 3 large residences, Dauphins, Leclerc and Gambetta, and rue Henri Regnault. In addition to its proximity to shops, the site is also close to transport links, with Cœur Transport and the future Eole station less than 10 minutes away on foot. Its strategic position offers the possibility of a new urban fabric and dynamic exchanges with Courbevoie.

The jury for the Ségoffin site met on 4 July 2023 and selected the Synapses project, led by Pitch Immo.

Synapses: the first mixed-use, innovative and exemplary footprint

The winning project for the Ségoffin site is Synapses, led by contractor Pitch Immo and developer GA Smart Building, and designed by urban architect Alfonso Femia. Synapses' ambitions for the area revolve around three main themes:

• Mixed use: Synapses will create a link between the slab and the city, with services for residents and employees,
• Urban links: Synapses has been designed as a neighbourhood-wide link between the Dauphins residence and Courbevoie. It creates a new route by redeveloping the Ségoffin crossroads, rue Serpentines and the area around boulevard Patrick Devedjian.
• Setting an example: Synapses meets the environmental ambitions of Paris La Défense by achieving the RE 2028 thresholds, using innovative materials and construction processes to create a harmonious, balanced, low-carbon building.

The Synapses programme meets the current aspirations of residents, employees, local users and the developer: local shops, services dedicated to soft mobility, restaurants and sports. This new meeting place, organised into two coliving buildings, the Serpentine and Ségoffin towers, will bring together on its base a varied range of offerings to flesh out the commercial side of the area. Take a guided tour of this future Curvois landmark.

A lively ground floor

The two-storey retail plinth will bring life to the new Patrick Devedjian urban boulevard and enhance the attractiveness of the area, with :

• A 300 m² Franprix supermarket
• A 400 m² restaurant
• A 600 sq. metre sports hall for people who want to exercise from morning to night.
• Activity rooms: multi-purpose room and third-location centre, concierge service, etc.
• Infrastructure for electric mobility, cargo bikes and repair tool kits and services will be provided. repair and service tool kits will also be integrated as part of a mobility workshop or kiosk.

Coliving spaces

The start-up Colonies, a national reference in the coliving market launched in 2017, will be the future operator of the coliving residence. It will offer large flats grouping around ten rooms with triple-oriented "private units" organised around a vast communal space, a large living room and a kitchen opening onto a private terrace. This choice of housing through the prism of collective coliving also reinforces the project's ambition for diversity, particularly by targeting young professionals and employees.

In addition to the collective dimension of the housing proposed by Synapses, there is a sequence of meeting and sharing areas (reserved for residents) covering 6,100 m², with rooms for coworking, projection, music entertainment and sport, as well as a laundry, a social lounge, communal gardens and a rooftop at the top of the Ségoffin tower to take advantage of the views over Paris La Défense.

The vegetated gap

The gap created between the two buildings is a major feature of the Synapses project. Its shape opens up the north-south perspective thanks to a series of steps on the two internal façades. This morphology makes it possible to open up visual perspectives while avoiding the barrier effect. The gap is enlivened by a series of terraces and planted balconies linked by staggered staircases. This is a real asset that enlivens and reinforces the landscape dimension of the project, while connecting the city and the business district.

A biodiversity-friendly rooftop

The future havens of peace for the building's users, one rooftop will be home to a vegetable garden and the other to furniture inviting people to relax and chat, sheltered under a pergola adorned with climbing plants.

Maintaining a network of associations

The project involves maintaining the community centre for people suffering from Alzheimer's disease in its current location, which will take over its direct environment through the use of plants and urban art, thanks to the respective skills of landscape designer WALD and urban art specialist Quai 36. The various programmatic and urban activities are also designed to reactivate the daily lives of these patients.

Synapses, an innovative design

The project proposes to make extensive use of the off-site construction processes mastered within the GA Smart Building group, in particular via its subsidiary Ossabois. This innovation enables the building components to be prefabricated: floors, façades and walls (2D), but also assembled in the workshop (3D). This construction model helps to meet social, societal and environmental challenges by :

• Reduce construction time by 30% and ensure a more reliable schedule.
• Minimise site disturbance for local residents
• Recycle waste
• Obtain an industrial quality finish
• Reduce the carbon footprint of structures by almost 40%.

Synapses, a bioclimatic project

The project was also selected because it meets Paris La Défense's low-carbon objective, with a footprint of less than 525 kgCO2eq/m², which complies with the ambitions of the RE2020 tertiary sector environmental regulations expected for 2028.

Stone and ceramics were chosen for their high technical performance, carbon neutrality and aesthetic appeal. The palette of light colours, such as sand and beige, creates a warm, harmonious dialogue with the vegetation of the faille and the rooftop. The curved architecture and double material of the two buildings will provide natural light throughout the day.

The transformation of boulevard Patrick Devedjian from a busy road into a calmer urban boulevard will include a 4-metre wide two-way cycle lane. To support these new uses, the Synapses bicycle storage facility will offer a full range of facilities dedicated to soft mobility, including parking, repairs and electric recharging.

The project aims to use water sparingly and reuse it:

• Rainwater recovery: a 15 m3 tank will be installed on the roof of the base to recover water and use it for watering.
• Grey water from the coliving area will be recovered and partly treated: it will be treated on site and then used to supply the sanitary facilities in the coliving areas.

Synapses, a new link in the Curvevois community

The winning team designed Synapses with two key ideas in mind: spaces for relationships and spaces for the senses. This future pathway is built around the strong presence of nature and the animated programming of the plinth.

The forecourts, or "placettes", are designed as visible meeting places around the new living spaces created by the programme (restaurant, sports hall, bakery, etc.). Existing green spaces will be preserved as far as possible (in situ or transplanted). The creation of pathways between the planted areas will calm the Ségoffin crossroads. A rotunda and a central pool will adorn the Ségoffin forecourt. Mineral bubbles, known as "synapses", will provide plenty of seating to encourage relaxation.

The public space will be adorned with trees of all sizes (notably Sequoia), accompanied by a symphony of native species and planted areas. In this way, the public spaces will offer a varied composition depending on the season and the path taken. The aim is to create an island of biodiversity, following on from Henri Regnault Square, which will continue in front of Les Dauphins residence, right up to the plinth.

The species will be adapted to the dense urban context of La Défense, ensuring that the plants are compatible with their environment.

The paths will follow the curves of Square Henri-Regnault and Rue Serpentines, linking the public space to the local square. The paths are designed to be sensory promenades, punctuated by a variety of vegetation and street furniture. Like the project as a whole, these links are designed to echo the animated base and flowering vegetation.

Did you know?

In science, the synapse represents the point of connection between two different disciplines that together lead to a new discovery. In this particular case for the Ségoffin site, the Synapses project connects the Paris La Défense slab to the town of Courbevoie. In addition to its roots, the winning project aims to create a real synergy between the offices and homes in the district.