« Switch to LEDs »: that is usually the full depth of office energy advice. We did the exercise for real, item by item, on our Courbevoie space. Measured result: -9.1% consumption over the last 12 months, and a total intensity of 61.9 kWh/m², already below the 2030 target of France’s tertiary decree. Here is exactly what we did, in order of what matters.
Item #1: ventilation, and the heat we used to throw away
Renewing the air of an office floor means continuously expelling air you have just heated, to draw in outdoor air that must be heated in turn. In 2026 the building’s air handling unit was fully refurbished, with one centrepiece: a custom-built heat-recovery unit.
Heat recovery: extracted air pre-warms fresh air
The principle fits in one sentence: extracted air crosses incoming air and gives up its heat, without mixing. At -7°C outside, fresh air already arrives at +7.9°C before any heating: 30 kW of power we no longer ask from the grid, across 6,000 m³ of air renewed every hour. The overhaul also brought variable-speed drives, new motors and a fresh-air by-pass for free mid-season cooling, plus a full cleaning and disinfection: better air, less energy.
Item #2: heat and light only what is occupied
- Reversible heating and cooling, adjustable office by office: each company picks its setpoint, and an empty office imposes nothing on the others.
- Lighting driven by 18 presence detectors across 12 zones, landing and washrooms included: light follows people, never the other way round.
Proof by the curve
Monthly consumption of the space, kWh
27 months of readings: seasonality remains, the level drops.
You can read an office’s real life in it: winters that consume, sober summers, and above all winter peaks sagging year after year: 2,871 kWh in January 2024, 2,464 in January 2025, 2,233 in January 2026, even before the refurbished ventilation’s full effect. March 2026 is the lowest point of the whole series.
And in your own offices?
Everything above is transposable, but demands continuous steering: readings, tuning, works arbitration. That is precisely what you outsource by choosing a coworking operator that does this work, with public numbers to show for it: our market position is in the meter-in-hand comparison, and what it removes on the regulatory side in our tertiary-decree article.
To see the machinery for real, from the heat-recovery unit to the detectors, book a visit: our Courbevoie offices are 10 minutes from La Défense, and we gladly show the engine room.