The administrative city of Amiens: a new reference in low-carbon construction for Bouygues Bâtiment Grand Ouest

After the rehabilitation project for the Administrative City of Rouen, the consortium led by Bouygues Bâtiment Grand Ouest won the construction of a new Administrative City, that of Amiens. This Global Public Performance Contract for a total amount of approximately €46,5 million is an exemplary project of 20 m² spread over 000 buildings which combines energy, environmental, functional and usage quality. The future Cité integrated into the ZAC Gare-La Vallée will accommodate 3 agents in the fall of 1100.

The Administrative City of Amiens is one of the 4 French administrative cities which are the subject of a new construction. Located in the heart of Amiens, the future City, said to be of the 170st century, will integrate the new district of La Vallée also called "Gare La Vallée", an urban project which extends over 9 hectares between the railways of the station of 'Amiens and the banks of the Somme. It was validated in the Amiens territorial development contract and aims to modernize public services and ensure the attractiveness of the territory. The design – construction – operation – maintenance consortium, led by Bouygues Bâtiment Grand Ouest, has 9 co-contracting companies with complementary expertise, thus contributing to the economic dynamics of the Picardy region. After 2021 and a half months of design, work started in October 2023 and will be completed in autumn XNUMX.

A low-carbon construction project

The future City was designed to be exemplary in terms of sustainable construction, that is to say both low energy consumption in the operating phase, while guaranteeing the comfort of agents and the public. It is aiming for the Passivhaus label, a level 3 bio-based building and a low carbon level E2C1.

To achieve these objectives, the project is based on several strong axes:

• A bioclimatic design which promotes energy savings, reduces heating and air conditioning costs while improving the living environment. Thus the volumes have been designed to promote natural light and benefit from solar gain. In addition, energy management will be optimal thanks to the connection to the district heating network and the future district cooling network;
• constructive solutions prefabricated in dry processes: the project integrates wood up to 95 dm3/m2 of floor with in particular the implementation of 9500m² of CLT (Cross Laminated Timber) wooden floors, i.e. a total of 1700m3 of wood for the floors. This project is one of Bouygues Bâtiment France's major timber projects, and the Bouygues Bâtiment Grand Ouest site teams responsible for its installation benefit from the support of WeWood, Bouygues Bâtiment France's center of expertise in timber construction.
• A thermal envelope very efficient (rock wool 220 mm thick for the facades, polyurethane insulation on the flat roof, fibrastyrene for the car park, efficient insulation of the stringers and slabs, etc.) and mixed wood/aluminium joinery fitted with triple glazing.
• Implementation natural materials such as, for example, Marmoleum floor coverings or Algo algae-based paint.

A project focusing on the comfort and well-being of officers and the public

Covering a total area of ​​20000 m2, the 3 buildings will house 18 administrative departments, ie 1 agents, an inter-administrative restaurant of 100 m900 and a crèche with 2 cradles with an adjoining garden. The flows will be well identified to optimize the reception of the public and the working environment of the agents.

The architecture of the 3 buildings is intended to be flexible, with modular interior fittings: the post-beam structure and the removable partitions have thus been designed to allow flexibility of the workspaces.

It is also based on the concept of biophilia, i.e. the integration of living things into the built environment, which translates into the enhancement of wood in workspaces, the revegetation of connecting walkways between buildings and outdoor spaces, etc.

Finally, the project will fit harmoniously into the neighborhood thanks to a large part of the facades of the buildings clad in glazed tiles.

This material echoes, in a contemporary way, the ubiquitous brick in Amiens. These tiles are produced locally, in Picardy, in Saint-Germer-de-Fly, by the company EDILIANS. The 7000 m² of enamelled tile cladding facades will be entirely carried out by the multi-skilled teams of Bouygues Bâtiment Grand Ouest.