What’s a Green Office®?

Renewable energy production by a Green Office® building

To offset their energy consumption, Green Office® buildings produce their own energy from renewable sources. Solar power, biomass, geothermal… the best sources are identified in accordance with the location and surrounding environment of each Green Office® project.

Green Office® Rueil is a building in synergy with its environment. Credits: Atelier Bilto Ortega

Green Office® buildings are positive-energy buildings, producing more energy than they consume for their operation. This technical feat is achieved by both reducing their energy needs and producing energy from renewable sources. 

Renewable energy

Energy generated from natural processes (sunlight, wind, wood, rain, geothermal, etc.). Contrary to fossil fuels, renewable energy is continually replenished and does not emit any greenhouse gases.

Definition from the French environment and energy management agency (Ademe)

Depending on the building’s location and surrounding environment, different sources of renewable energy can be used, either alone or combined to complement each other.

  • Solar power: solar thermal or photovoltaic panels can be installed on the roof or around the building, integrated directly into the façade or on car park shelters. Green Office® Meudon boasts 4,200 m2 of photovoltaic panels whose energy production is sold to the energy dealer.
  • Biomass: the combustion of plant, animal or fungal organic matter is a source of energy. Green Office Meudon® is equipped with a cogeneration plant that provides both heat and power simultaneously by burning rapeseed oil sourced from the Paris region. The plant covers all the building’s heating needs and 55% of its power needs.
  • Geothermal: using either dry boreholes or groundwater heat pumps, geothermal energy involves converting heat sourced from the ground to deliver power to buildings. Hydraulic studies carried out around Green Office® Rueil have shown that there are sufficient groundwater levels to cover the building’s energy needs.

Green Office® Meudon has 4,200 m² of photovoltaic panels. Credits: Vincent Fillon

Compenser les consommations du bâtiment

Green Office® Rueil offsets its consumption via the production of renewable energy. Credits: Atelier Bilto Ortega

Positive-energy buildings offset their regulated energy use by producing renewable energy over a one-year period. Green Office® Rueil’s regulated energy use is offset by 2,100 m² of rooftop photovoltaic panels. The panels will produce around 320,000 kWh of energy, which corresponds to the building’s entire annual energy consumption.


Delivering on its promises

After its first year in operation, Green Office® Meudon produced an energy surplus.
  • Energy production: 76.9 kWh/m²/year (compared with 64 kWh/m²/year initially projected).
  • Total energy use: 70.8 kWh/m²/year (compared with 62 kWh/m²/year projected).