Long perceived as a mere administrative formality, the commercial energy audit has become a true strategic compass. It is no longer simply a matter of "taking stock of the situation," but of outlining a concrete and profitable decarbonization path. For stakeholders in the commercial sector, it represents the essential starting point for any serious renovation, enabling a shift from reactive energy management to intelligent and predictive control.
In this comprehensive guide, we decipher the new rules in force since the transposition of the Energy Efficiency Directive, the obligations linked to the Tertiary Decree, and above all, how to transform this diagnosis into an immediate action plan to reduce your operating costs.
What is a tertiary energy audit?
A commercial energy audit is a detailed analysis of the energy consumption of a building or a group of buildings. It allows for the creation of a precise map of energy flows in order to identify sources of waste and propose costed renovation scenarios.
According to the latest 2025 report on regulatory energy audits, this tool has become an effective instrument for maintaining business competitiveness. It does more than simply list equipment; it serves as a foundation for:
- Evaluate the current performance of the systems (heating, lighting, ventilation).
- Identify priority actions to reduce energy bills.
- Develop a solid and realistic decarbonization plan.
Read also: industrial energy audit
Why does a commercial energy audit exist, and what is its purpose?
The primary objective of this initiative is to engage service sector stakeholders in a trajectory of massive greenhouse gas (GHG) reduction. The sector is a major contributor to national energy consumption: large companies registered on the audit collection platform alone account for 15% of final energy consumption in France and 16% of GHG emissions. However, the potential remains immense, as only a third of the companies concerned are currently included in official reports.
The audit therefore serves as a compass to guide investments towards energy efficiency while ensuring the economic sustainability of the company in the face of rising energy costs.
Who is subject to the tertiary energy audit?
For a long time, the obligation to conduct an audit was based on the size of the company. Until recently, it concerned structures with more than 250 employees or those exceeding 50 million euros in turnover (with a balance sheet total of 43 million euros).
However, the rules of the game have changed with the Energy Efficiency Directive (EED). Since October 2025, the selection criterion has become clearer and now focuses on actual consumption:
- Companies consuming more than 2.75 GWh/year: Energy audits are now mandatory, regardless of the size of the structure (including some energy-intensive SMEs).
- Companies consuming more than 23.6 GWh/year: They must implement an energy management system certified to ISO 50001.
This development, to be enacted into French law by October 11, 2025, concerns a wide variety of sectors: supermarkets, nursing homes, head offices, call centers, and IT services.
Who is exempt from tertiary energy audits?
There is an alternative way to meet your regulatory obligations. If your company has a ISO 50001 covering its entire scope, it is exempt from the regulatory audit.
The 2025 assessment shows that companies are making a variety of choices:
- 87 % The files submitted on the ADEME platform are audit reports.
- 10 % rely solely on ISO 50001 certification.
- 3 % combine both approaches for maximum performance.
In summary, to be compliant, your file must include either an audit report less than 4 years old, or a valid ISO 50001 certificate (usually 3 years old).
Read also: Tertiary sector decree for local authorities
What are the obligations related to the tertiary energy audit?
Conducting an audit is not something that can be improvised. It must comply with strict standards (notably the EN 16 247) which define the methodology and the minimum dataset to be collected.
Furthermore, the tertiary sector energy audit is closely linked to the Tertiary Decree. This decree requires companies with more than 1,000 m² of tertiary activity space to declare their energy consumption on the OPERAT managed by ADEME. The audit provides the essential technical data needed to populate this platform and demonstrate that the reduction targets have been met (-40% by 2030, -50% by 2040, -60% by 2050).
Top actions recommended following a commercial energy audit
The audit leads to concrete recommendations. Based on ADEME's experience with over a hundred recent audits, the most cost-effective actions focus on three key areas:
- The building structure and envelope: Insulation, joinery and waterproofing.
- Lighting: Switching to LEDs and intelligent control.
- Energy management: Implementation of a consumption monitoring system, training of teams and optimization of supply contracts.
The median gains identified are significant: modifying the energy mix can generate a gain of 73 MWh/year, while optimizing heating and heat distribution installations saves approximately 25 MWh/year.
Why conduct a commercial energy audit?
Beyond the obligation, auditing is a profitable investment on several levels.
Compliance
The service sector represents 48% of companies registered on the ADEME platform. Being compliant means avoiding administrative penalties, but it also means anticipating future, increasingly strict regulatory restrictions.
Competitiveness
The figures speak for themselves: the assessment conducted between 2021 and 2025 identifies a median energy savings of 10% from the very first actions. In certain sectors, such as catering or call centers, potential savings can reach up to 37%. By reducing your expenses (HVAC, lighting, refrigeration), you directly improve your operating margin.
Attractiveness
A company that manages its energy footprint strengthens its brand image. This is a powerful argument for attracting investors, reassuring customers, and retaining employees who are increasingly sensitive to their employer's CSR commitments.
Who should be asked to carry out a commercial energy audit?
To guarantee the validity of your audit and the relevance of the recommendations, it is crucial to use an expert partner, capable of navigating between technical and regulatory constraints.
Powesco: Much more than a diagnosis, a turnkey performance strategy
Powesco 's strength lies in its ability to go beyond simply providing a paper report. Where many consulting firms stop at a list of recommendations, we have chosen concrete application . We conduct the commercial energy audit and deploy the technical solutions to guarantee results.
- The energy audit by Powesco: The starting point
Our experts conduct on-site assessments to perform a comprehensive analysis of your facilities. We don't just read meters; we study your usage patterns, the age of your equipment, and the specific characteristics of your business (offices, warehouses, retail). The result: A prioritized action plan based on return on investment (ROI) and carbon footprint.
- Energy renovation of buildings
The audit often reveals weaknesses in the building's thermal envelope. Powesco handles the recommended renovation work
- Attic and wall insulation.
- Replacement of the joinery.
- Improved sealing. The goal is simple: drastically reduce your passive energy needs even before optimizing your machines.
- Smart lighting: The quick win
Lighting often accounts for 12% of a commercial building's energy consumption. It is one of the most effective levers identified during our audits.
- LED Relamping : We replace your old systems with high-performance LED solutions.
- Automated management: Installation of presence detectors and light sensors so that energy is only consumed when necessary.
- Energy management and control
To ensure lasting savings, the audit almost always recommends improved energy management (Energy Management System or equivalent). Powesco deploys real-time monitoring tools:
- BMS (Building Management System): Centralization and automation of heating, ventilation and air conditioning (HVAC).
- Consumption monitoring via SEME Nextep: Implementation of dashboards to identify any consumption deviations immediately.
- Contract optimization: Adjusting your contracted power levels to closely match your new, reduced needs.
Why choose Powesco for your audit and its application?
Having Powesco conduct your audit means choosing consistency. By entrusting us with both the diagnosis and the implementation, you benefit from:
- A single point of contact: No more loss of information between the design office and the construction companies.
- A guarantee of results: Our solutions are precisely sized based on the audit data.
- Optimized financing: We support you in mobilizing aid (CEE, subsidies) to reduce your out-of-pocket expenses.
A commercial energy audit is not an end in itself; it's the driving force behind your transformation. Ready to take action?
Sources:
