Energy consumption reduction solutions for your offices
Framework: three milestones through to 2050 and penalties of 7,500 EUR
-40% by 2030 is the legal floor, not the target: aiming for -45% from delivery secures the OPERAT 2040 trajectory without a second project (decree 2019-771, article R.174-32). Energy consumption reduction in offices is not determined by the 2050 trajectory, but by the reference year chosen between 2010 and the second-to-last year declared, which accounts for 60 to 80% of the reported result. Across a French tertiary building stock of 960 million m² consuming 220 kWh/m²/year in offices (ADEME, Chiffres-clés du bâtiment 2023), the direct potential represents 12,000 to 25,000 EUR per year for a typical floor plate. Kytom, founded in 2006, combines NF EN 16247-2 audits, dynamic thermal modelling and a works programme integrated into the fit-out, with a 24-month post-delivery follow-up that stabilises gains where an underused BMS would lose 15 to 25% of its potential.
The tertiary decree, resulting from the ELAN law (2018), requires an annual OPERAT declaration for any tertiary site of at least 1,000 m², with penalties of up to 7,500 EUR per building (decree 2019-771, article R.174-32 of the Construction Code). The trajectory follows three regulatory milestones:
- 2030: -40% compared to a reference year after 2010
- 2040: -50%
- 2050: -60%
The BACS decree (2020) adds an automation requirement for HVAC systems above 290 kW by 2025 (decree 2020-887). The European taxonomy and the CSRD directive increase investor pressure on the green value of assets held for more than 5 years.
On the occupational health side, articles R.4222-1 et seq. of the Labour Code govern indoor air quality, which prohibits any HVAC optimisation that degrades air renewal. According to the Cerema (Parc tertiaire et rénovation énergétique, 2022, p.14), 35% of the tertiary stock predates 1975, which sets the works scope at 60-70% of envelope actions. For a typical floor plate, avoidable energy charges range between 12,000 and 25,000 EUR per year, representing the direct potential of the low-carbon trajectory.
Frequently asked questions
Which OPERAT reference year should you choose to maximise the -40% trajectory by 2030?
The reference year is chosen between 2010 and the second-to-last year declared (article R.174-32). This choice accounts for 60 to 80% of the reported result: a high-consumption year, marked by full occupancy, a harsh winter or ageing equipment, mechanically makes reaching -40% by 2030 easier. The regulatory energy audit must incorporate this calibration from the initial scope.
