Short Description

The Ampère e+ building is the new headquarters of Société Générale’s SOGEPROM, located in the heart of the business district of La Défense. The building, built in the 80s, has currently undergone a major and ambitious renovation after it was completely laid bare to maintain only the structure. It is from this basic structure that the architecture agency “Atelier 2/3/4” redefined not only the envelope of the building, but the concept in order to fit into a vision of current concerns. Ampère e+ is innovative, and fits perfectly into a dynamic of an urban context with ecological ambitions.


The project transformed the former Ampère building into 14,200 m² of connected offices with 1,200 m² of average surface area over 9 floors and external spaces at each level, accommodating a workforce of 1,299 people. It integrates many services for future users, starting with a car park of 200 places, 30 of them for electric vehicles on two levels of basement, a company restaurant, a cafeteria opened onto a landscaped garden, accessible terraces, a concierge, an accessible rooftop, etc.

A place for environmental innovation

The Ampère project will be a source of inspiration for all the stakeholders involved in the transformation of the business district of La Défense, a neighborhood that is constantly being redeveloped. SOGEPROM wanted to make it a showcase of its property policy by proposing technical innovations in energy and developing solutions for the well-being of its employees.

Intended Use

Office building with meeting rooms, a restaurant, shared spaces and outdoor spaces


  • Project Architect(s):

    Atelier 2/3/4

  • Project Developer(s):

    Sogeprom Entreprises

  • Project Engineer(s) & Contractor(s):

    Facade: Arcora
    Structure: Scyna 4
    Environment Consultant: Etamine
    Acoustics: Peutz
    Economist: GVI
    Landscaping: Faubourg 2/3/4/
    Roads & main networks: Infra Services
    Vinci Construction France
    Vinci Energies

  • Project Advisor: Lateral Thinking Factory Consulting (LTFc)

Project Showcase


  • Air System

    • ⁂ Enhance Air Quality and Indoor Climate ()
    • Positive Impact

      The matter of Indoor Air Quality (IAQ) was of most interest even before the renovation work started, with the use, as of 2014, of a measurement device on the roof-terrace of the Ampère e+ building. An IAQ study has therefore been conducted for the upper part of the building, followed by one on the lower part, after the measurement device got relocated at ground floor in February 2015.
      Improvement of IAQ with the \"qai3+\" concept: the amount of renewed air is increased of 50% compared to Real Estate standards for office buildings and a reinforced air filtration system with active charcoal filters has been implemented.
      BIOORG Bio-organisms cleaning and maintenance products: BioOrg places positive organisms in such environments, which automatically clean up the visible and invisible pollution. These organisms carry out their cleaning action not only in the easily accessible locations, but also in the remaining 80% of a building or installation. This ultra-modern treatment creates a new and healthy balance without the use of harsh chemical products, and has a curative and preventive effect. BioOrg gives people the environment they need: filled with clean air and pure water. The probiotics are effective at cleaning indoor spaces naturally.

  • Facade

    • ⁂ Enhance Air Quality and Indoor Climate, Healthy Materials
    • Positive Impact

      Natural ventilation of the building
      The building facades have been designed to meet different contexts and orientations: thin double-skin facades were put in place with regularly disposed opaque openings. These openings are also protected by perforated plates acting as a filter for noise and air pollution.
      The building has four types of facades, according to the orientations and the different urban contexts. The design of these facades meets three criteria: water and air tightness of the building, strength and durability over time, and ultimately ease of access and maintenance. Indeed, the four types of facades are defined in such a way as to eliminate the thermal bridges.

    • Benefits

      Thus, the four types of facades meet the needs of users in indoor spaces in relation to external contexts: orientations and brightness, work spaces and shared spaces, ceiling heights according to the type of space, etc. Finally, these four types of facades also respond to the well-being and the comfort of users, with a real aesthetic concern: continuity and regularity of the components for an architectural exterior fluidity, natural ventilation and opening elements, with filters at the levels of openings for the cleaning of incoming air, blackout system with opaque aesthetic elements, and motorized blinds for controlling the interior lighting environment, etc.

    Element Showcase

  • LIFI & Direct Current (DC)

    • ⁂ Celebrate Conceptual Diversity with Innovation
    • Positive Impact

      Direct Current (DC) & Li-Fi (Light Fidelity) is a high-speed and fully networked wireless communication technology similar to Wi-Fi that uses UV, visible and infrared light in order to deliver data. Using the visible-light spectrum, the system can have both purposes at the same time: lighting the building users (with LEDs) and be an alternative to the usual Wi-Fi technology, which starts to see his RF-bandwidths limited. This system strongly reduces the amount of electromagnetic fields - ideal for electromagnetic sensitive areas such as in aircraft cabins, hospitals and nuclear power plants, to not cause electromagnetic interference -, as well as the total length of cables, often built in PVC, which is a forbidden material in C2C design because it releases fine particles. An additional benefit is that light waves cannot penetrate walls which makes a much shorter range, though more secure from hacking, compared to Wi-Fi.
      The Li-Fi system has been implemented by the French company “Lucibel”, making the Ampère e+ world's first building to use this technology.

    Element Showcase

  • Finish - Walls

    • ⁂ Enhance Air Quality and Indoor Climate, Healthy Materials
    • Positive Impact

      Filtering Indoor green walls
      These walls promote a good IAQ as well as a quiet atmosphere

    • Benefits

      The interior green wall will purify the indoor air and give a welcoming atmosphere for the employees.

  • Energy (electric)

    • ⁂ Integrate Renewable Energy
    • Positive Impact

      One of the fundamental ambitions of the Ampère Building was to put together an energy efficiency at the start, by producing energy, by recovering the energy inherently trapped in systems that would be lost, and finally by storing energy within the building that could be sent back into the grid.

      Amongst the very innovative features in the e+ Building are: the reuse of e-cars batteries as a reservoir for electrical energy; a Li-Fi dedicated space (Internet connection via the light), Ampère e+ is equipped with a Building Management System (BMS), lit by LEDs, has 230 m² of PV panels and a network enabling the collect of rain water, and finally recovers kinetic energy from the lifts for the supply of local functions.

      Two different local sources of renewable energy will be implemented on the e+ building:
      1. An energy production from PV panels located on the roof: 230m² aiming at producing a power of 60KWc. The DC current provided thanks to solar energy will then be transformed into AC current in order to power electrical devices in the building. This produced energy will be self-consumed in the building as electricity.
      2. An energy production from wind energy via the implementation on the roof of the 10th floor from the NewWind company. The electricity produced will also be used directly on site.
      Furthermore, the building is connected to the Heating and Cooling network of the business district, called Enertherm.

    Element Showcase

  • Green Spaces

    • ⁂ Integrate Biological Nutrients, Healthy Materials
    • ⁂ Actively Support Biodiversity
    • Positive Impact

      An improved outdoor landscape
      Accessible green spaces
      A planted boulevard
      Landscaped lodges
      Hives on roof

    Element Showcase

  • Energy Storage and Erasing System

    Air System

    • ⁂ Integrate Renewable Energy
    • Positive Impact

      Energy Storage and Erasing System
      In addition to a local energy production, the e+ building is designed to store this energy on site to function as an energy reservoir. This translates into three systems:

      1. Implementation of an energy tank system by electric vehicle batteries:
      The batteries are recharged either by renewable energy (photovoltaic, wind) or by off-peak power, to compensate for peak electricity consumption during full-hour tariff periods. The batteries and their charging / discharging system and their control process are positioned in a technical room in the basement complying with the regulations of a local inverter, with ventilation and fire safety system adapted.

      2. Implementation of an electric vehicle charging terminal system which during their parking and charging periods is used as electricity storage batteries but also as an offset for peak loads during periods of low demand.

      3. Implementation of elevators operating on rechargeable batteries. The elevator, although known as an energy consumer, can also become a producer when braking or when the counterweight becomes heavier than the cab. Otis, with its ReGen Drive energy recovery system mounted on the latest generation of Otis lifts, recovers this kinetic energy for the supply of either local electrical functions, other elevators in the building or utilities of the building.

      The batteries of the elevators are charged either by the recovery of kinetic energy during the braking phases of descent of the devices or by means of renewable energy (photovoltaic, wind), or by means of the 220V single-phase cabin electrical connection.

      Reduction of energy consumption within the Building
      Technologies have been implemented within the e+ Building in order to reduce the general usage of energy consumption. These technologies include:
      - Implementation of LED lighting equipment for indoor spaces;
      - Implementation of active glazing systems;
      - Implementation of fiber optic-fueled hybrid lighting systems and LEDs;
      - Li-Fi spots, provided by LUCIBEL, will be set up in the equipped spaces as meeting rooms, in addition to those planned;
      - Implementation of an erasure strategy of power consumption or smoothing of the load curve by the control of the demand.
      In the event of an electricity supply/demand imbalance, the erasure consists in temporary reducing the physical consumption of a given site or a group of actors (in relation to its “normal” consumption), the erasure being triggered by an external stimulation.
      Erasure is a key point in the TIR (Third Industrial Revolution) dynamic. It is facilitated by the development of “smart grids” enabled by ICTs, with the use of industrial controllers or smart meters as the Linky3. The once pyramidal and centralized structure of the electricity system tends to become more horizontal and to give consumers a more active role while allowing for a more efficient and safe system.
      Finally, the use of high-performance artificial lighting with LEDs in the building will reduce the heat emitted by lighting. In addition, it is intended to regulate the lighting according to the external natural luminosity, so as to use only the necessary.
      In addition, it will be recommended to choose computing equipment that are less consuming in order to reduce electrical energy consumption and refreshment requirements.

    • Benefits

      The implementation of an erasure strategy is a strong point, by the intelligent connection of two entities that meet different needs: for the user - the Ampère building, this allows to draw up a more competitive contract with the energy provider, and to make profitable the setting up of car batteries for storage. For the energy supplier, this allows it to limit peaks in energy consumption and to balance the demand on the network.
      The project's design made it possible to obtain a carbon impact (CO2 emissions) of 60% lower than the ADEME data for a new building equivalent, and 54% less gray energy production compared to environmental ambitions 2016 , which is a major element on the virtuous and innovative character of AMPÈRE e+.

    Element Showcase

  • Energy Management System


    • ⁂ Energy Management
    • Positive Impact

      The building will also be the first in Europe to be equipped with an energy management system, be + ms (Building Energy Management System) which was developed from two other innovations implemented on AMPÈRE e+, b4b (energy storage with second-generation Renault electric vehicle batteries) and the Otis ReGen (energy recovery from lifts to downhill and braking). The be + ms thus controls the generation of energy generated by the building, its storage and the optimized management of its consumption. This system was developed under the auspices of the European Commission in partnership with the United Technologies Group, Otis, Renault Group and Bouygues Energies et Services.

    Element Showcase


  • Improvement of Well-Being & Productivity

    • Positive Impact

      In E +, the users are at the heart of the concerns: they have access to natural light, a fine air quality and the possibility to open windows to renew indoor air, to control and adjust the light intensities via Smartphones and tablets, etc. All this is made possible by the use of a dedicated digital application enabling all employees to optimize the comfort of their desk environment.

      The building offers many advantages such as:
      • More meeting rooms on all floors
      • Relaxation areas for all users
      • More natural light of pure chromatic quality
      • Intelligent facades
      • An improved outdoor landscape

    • Benefits

      The new building has been designed for future users, taking into account the need for well-being in the professional space. Thus, many arrangements have been developed. Two of them have a significant spatial impact:
      - Small meeting rooms at all levels: they represent 8% of the office space, located in close proximity to vertical ducts or expectations in false ceiling, allowing the modularity of these spaces. Giving access to meeting rooms offers flexibility to open-space users, who can thus easily isolate themselves as required;
      - Relaxation spaces at all levels: depending on the future occupants of all levels, these spaces can be occupied differently. Under the model of the tea lounge, these spaces will have pending expectations in water and electricity.

      Other arrangements have been made to improve the comfort of future users in the Ampère building, from the largest to the smallest, here are some of them:
      - A design that brings natural light in: natural light is a fundamental principle for well-being, and as a result, all rooms have access to natural light. This was made possible by studies on the luminosity of the building, and a work on the structure, carried out to bring natural light to the level of the garden (in the meeting rooms) through the implementation of patios. In addition, glass windows located in the upper floor of the entrance hall of the building allow the transmission of natural light;
      - Active glazed partitions: this technology is programmed on the partitions of some meeting rooms overlooking corridors in order to isolate the space when needed. The active glazed is implemented by the Magic Film Opacifiant, a specific film dedicated to the opacification of glazed surfaces that are sticking to them, the meeting rooms can become isolated spaces by a simple control on switch.
      - Protections against the sun: the solar occultation occurs at several scales and levels in the building. First, fixed sun breezes in vertical screen-printed glass slides are arranged perpendicularly to the facade, protecting the users of the sun. In addition, motorized Venetian interior blinds have been installed to control the luminous ambiance of the interior spaces.

    Element Showcase

  • Flexibility & modularity

    • Positive Impact

      A few arrangements have been adopted in order to make the Ampère e+ building sufficiently flexible.
      On the design of the spaces, the platforms will be delivered in Open Space, allowing a partitioning according to the choice and the needs of the future takers, by the installation of removable partitions. This makes it possible to remain flexible on the uses of each floor, since they were designed to be divided into two batches, working together or individually. The building can be rented either for a single company or for multi-tenant.

    • Benefits

      The following arrangements will therefore be provided for each half-floor (except the ground floor, consisting of a single lot):
      - Divisional panels, electrical distributions and sub-meters:
      - Precautionary measures for future access controls
      - Acceptance of easements of evacuation from one compartment to another
      - Open spaces
      - Partitioning
      The office operation is delivered without partitions, and considered to be compartmentalized later. The offices have been studied for operating in open spaces or with partitioning walls. Similarly, the location of the networks leaves a great flexibility in the use of the floors: the horizontal aeraulics and hydraulic networks specific to one lot can go through another batch without having any organ requiring adjustment or maintenance (valves, meter, etc.).

      In addition, a system of modular glass partitions was developed for the offices areas. The spatial changes can be made very easily: these panels can be dismantled individually without having to move the adjacent panels. Likewise, the elements of partitions are modulated, and all the panels respect the frame of the building.

      Finally, several technical elements inside the building are left as precautionary measures in order to allow a future modularity of the spaces. For example, with the integration of standby power supplies and evacuations, such as the faucets provided on each floor for future cafeterias and beverage dispensers, as well as faucets and floor drains in technical rooms, accessible terraces and outdoor spaces. Similarly, technical rooms are designed as precautionary measures, thanks to the transformation of a dedicated space in each lot that can be converted into a private technical room by the tenant if necessary. This can be achieved by fuse reservations in concrete floors (in technical ducts or in false floors). These fuse reservations are equipped with protective sleeves at the crossings of floors, allowing vertical links between floors without demolition.
      These convertible areas will be equipped with 4 kW refrigeration equipment for the potential future cooling of the active machines of these premises, produced from a dedicated refrigeration unit. The outdoor building design enables the frame of the facade of the Ampere building to be suitable for internal modularity. Indeed, all the facades of the building are weaved to allow an indoor partition with modules of 1.30m wide. This frame corresponds to the existing building frame.

    Element Showcase

  • Mobility

    • Benefits

      The Ampère e+ building is accessible from public transport modes, giving pedestrian access to the entrance and reception areas. Users are also able to go to the office by bike, leaving their bikes in a bicycle shelter on the ground floor of 44 places. Finally, users can also ride their car and park it in the second and third basement parking, which also gives access to charging jacks for electric cars. It is planned to promote the use of public transport solutions by communicating around the schedules of transport, accessibility and plans, etc.; as well as setting up an Internet platform to promote inter-building car-pooling.
      Implementation of intelligent electric vehicle charging stations, developed by the French startup G2 Mobility, which will allow the deployment of a new functionality of reservation of the EVs in auto-sharing on the m2c mobile application.
      Installation of a network WiFi terminals counting the places in the parking lot, developed with the French startup OneSitu, which communicates directly with m2c.

    Element Showcase

  • Innovative in collective intelligence

    • Benefits

      The Ampère e+ building is equipped of connected controlling systems (Bluetooth, smartphones/computer) in order to regulate the comfort of every user:
      - access control via Bluetooth
      - lift control pre-destination
      - technical functional control (working space temperature, lightning and occultation, etc.)
      This data will be accessible by the users, by virtual remote controls. They will be able to control their environment from their workplace (hygrometry, acoustics, air quality, parking lot availability, advanced management of meeting rooms, active glazing for occultation, fire safety, etc.).

    Element Showcase

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