Launched in 2020, the renovation of the Saint-Sever administrative center in Rouen is currently almost complete at a cost of 96 million euros.

This 1960 construction, which covers a total area of 44,000 m², had never before been the subject of renovation work and had a high energy efficiency rating. The conception-implementation market validated by the government and entrusted to Bouygues Bâtiment Grand Ouest relies on local companies for a 70% minimum reduction in energy costs and the labeling of the building as BBC Rénovation. The 3-year phased project is the first city to be rehabilitated in France as part of a government investment program.

Conservation and mise en conformité of existing chaufferies

CLEVIA Normandie (76) coordonne et supervise le lot CVC. All of the existing chaufferies have been preserved, the work includes the replacement of the electropump of the primary chauffage network as well as the installation of a tampon gas bottle made of stainless steel on the supply of each chaufferie. The safety of the system is ensured by the possibility of basculement on a safety water heater with the aid of 2 motorized lines. Two horizontal collectors for supply and return are installed to distribute the various hydraulic circuits. The entire pump is equipped with variable speed to limit consumption.

Panneaux rayonnants hydrauliques et régulation thermocyclique

For the heaters, the choice is naturally based on radiant panels with hot water which, installed in the false ceiling, ensure homogeneous and modular heating in complete discretion. The radiant panels are regulated by the ThermoZYKLUS certified eu.bac system with a Ca = 0.4 in cold weather and 0.4 in cold weather. The thermocyclic regulation pilots the panneaux dynamically in order to achieve an equal level of comfort and optimized consumption by eliminating the surcharges, taking into account the gratuitous use of the apports, automatically detecting the opening of the window without the need for contacts and the possibility of programming and reducing the temperature depending on the occupation. The result: energy consumption reduced to a strict minimum thanks to its precision of +/- 0.15°C and optimum thermal comfort.

Contrôle optimal de l'installation via GTB

In the offices, meeting rooms, halls and workspaces, an aveugle filaire ambiance probe RS is installed in each room to regulate. Associated with an auto-equilibrating SK fan motor, it communicates the data in real time to the ZE regulation unit, which controls the energy output according to the room's consumption temperatures and requirements. The installed motors require a simple bus connection, which is an indispensable advantage, both in terms of reduced installation time and installation economy, with an installation effort reduced by 10 on average compared to expensive individual power supplies. The possibility of mounting them directly on the power supply units in the remote control panel avoids any unnecessary degradation and ensures the reliability of the installation. Without the possibility of local command to avoid unintentional manipulation, the terminals are positioned on the building's technical management system to allow optimum monitoring of the installation without local modification. The integration of the regulation ThermoZYKLUS in the GTB facilitates the programming according to occupancy planning, the precise control of the ventilation via ST commutators and presence detectors. In total, on-site chauffage is now regulated by a trentaine of central units with the help of more than 700 temperature sensors and 700 fan motors. The latest phase of the work envisages the installation of 26 central units, 630 sensors and 650 additional engines, all of which will be 100% autonomous and maintenance-free to achieve operating efficiencies in line with the 75% target set by the Minister of Action and Public Accounts when the project was presented.

Maître d'ouvrage: Préfecture de Seine-Maritime. Acteurs du projet: BOUYGUES BATIMENT GRAND OUEST (mandataire et constructeur), ARTEFACT (architecte), ELAN (space planner), SOGETI (BET lots techniques), ALBEDO (BET thermique et environnement), ECONOMIE 80 (économiste), DECAUX PAYSAGE CONCEPT (paysagiste), ACOUSTIBEL (BET acoustique), METROERGO (ergonome), CLEVIA Normandie (lot CVC).