Mis à jour le 13 juin 2026

The mandatory energy audit for businesses is a bit like spring cleaning for your energy consumption. Gone are the days when you could ignore your energy bill; now, you have to look at it seriously. But who is actually affected by this obligation? And how does it work in practice? We’ll break it down to help you see more clearly.

Key Takeaways

• The mandatory energy audit applies to companies whose average annual final energy consumption is greater than or equal to 2.75 GWh. The previous criteria based on company size (employees, turnover) have been removed. The scope of application is now based on the SIREN number.
• An average consumption of 23.6 GWh or more requires the implementation of an ISO 50001 certified energy management system (EMS). Companies have specific deadlines to comply: either an EMS certified before 11 October 2027, or the first energy audit before 11 October 2026.
• Exemptions exist. If a company has already implemented a certified energy management system (e.g., ISO 50001), obtained ISO 14001 certification including an audit, or signed an energy performance contract, it may be exempt. This must cover at least 80% of its final energy consumption.
• The audit must be carried out every 4 years. The resulting report must detail consumption, identify significant energy uses, and propose quantified improvement actions with their profitability. Recommendations must be implemented within 5 years.
• To carry out the audit, companies can use qualified internal auditors or, more commonly, specialised external service providers. The latter must comply with reference standards, particularly the NF EN 16247 series. Failure to comply with these obligations can result in fines of up to 2% of turnover, or even 4% in case of repeat offences.

Which Companies Are Affected by the Mandatory Energy Audit?

Since 2014, a European directive has required large companies to conduct an energy audit. The main objective is to promote energy efficiency and reduce overall energy consumption within companies. This obligation is part of a broader initiative to improve the energy performance of the economic sector.

Determining Energy Consumption Criteria

Eligibility for the mandatory energy audit is now primarily based on final energy *consumption*. Specifically, any company whose average annual final energy consumption over the last three years is greater than or equal to 2.75 GWh is affected. This threshold applies regardless of the company’s size in terms of staff or turnover.

Abolition of Previous Company Size Criteria

It is important to note a major change introduced by the DDADUE law. The previous criteria based on company size, such as the number of employees (over 250) or turnover, have been abolished. From now on, only the energy consumption criterion determines the audit obligation. This means that companies of all sizes can be affected if they exceed the established consumption threshold.

Scope of Application at the SIREN Level

The mandatory energy audit obligation is now assessed at the company’s SIREN number level. This means that the consumption of all legal entities linked to the same SIREN are aggregated to determine if the consumption threshold is met. The audit must cover at least 80% of the final energy consumption of all activities under that SIREN.

The mandatory energy audit is a decision-support tool. It provides a precise overview of energy consumption and identifies concrete avenues for improving energy performance, leading to a quantified action plan.

Companies that exceed a certain energy consumption threshold are therefore directly concerned by this process. For example, industrial companies that consume a lot of energy must comply with this regulation. It is therefore essential to accurately assess your consumption to know if you are subject to this obligation. For more details on the obligations, consulting the Energy Code may be useful.

Energy Consumption Thresholds for Eligibility

2.75 GWh Threshold for Energy Audit

To determine if your company must undergo a statutory energy audit, you need to look at its energy consumption. More specifically, the average final energy consumption over the last three calendar years is examined. If this average reaches or exceeds 2.75 gigawatt-hours (GWh), then the obligation applies. This is a significant change from the old rules which were based on company size, such as the number of employees or turnover. Now, consumption is the deciding factor, regardless of your organisation’s size. It should be noted that this audit must cover at least 80% of the company’s total energy consumption, based on invoices to cover significant uses.

23.6 GWh Threshold for Energy Management System

There is another, higher threshold: 23.6 GWh. If the average of your annual final energy consumption over the last three years exceeds this amount, you are obliged to implement a certified Energy Management System (EMS). This system must comply with the ISO 50001 standard. If you do not yet have a certified EMS, you have until 11 October 2027 to implement it. This is a more advanced process than an energy audit, aiming for continuous energy efficiency management.

Scope of Energy Consumption Considered

When referring to energy consumption for these thresholds, everything that is invoiced must be included. This includes electricity, natural gas, fuel oil, butane propane, petroleum coke, steam, hot water, biomass, and all fuels. It is important to note that even renewable energy produced and consumed on-site is included in this calculation. Internal waste heat recovery, if not invoiced, is not directly included in the invoice-based scope, but its optimisation remains a key point to consider in the audit. The idea is to have a comprehensive view of all consumption points for a complete analysis.

All final energy consumption, including that from self-produced and on-site consumed renewable energy, must be considered to determine eligibility for an energy audit or the implementation of an energy management system.

Exemptions from the Mandatory Energy Audit Obligation

Implementation of a Certified Energy Management System

For companies that have already implemented a certified Energy Management System (EMS), there are exemptions from the mandatory energy audit obligation. The ISO 50001 standard is the most common reference for these systems. If your certified EMS covers at least 80% of your energy consumption, you may be exempt from conducting a statutory energy audit. This recognises the commitment of these companies to a structured approach to improving their energy performance. The aim is to avoid duplication with efforts already undertaken and recognised by a recognised certification. Companies certified to ISO 50001 are therefore exempt from the mandatory energy audit, provided that this certification covers at least 80% of their energy consumption. This certification offers flexibility.

ISO 14001 Certification and Energy Performance Contract

Beyond ISO 50001 certification, other arrangements can exempt you from the mandatory energy audit. ISO 14001 certification, which relates to environmental management, can also grant an exemption, provided it includes a form of energy audit. Similarly, the implementation of an Energy Performance Contract (EPC) can satisfy this obligation. These options show that the legislator recognises different pathways to achieve energy efficiency goals, thereby valuing companies’ proactive initiatives.

Coverage of Consumption by the Management System

It is important to note that to benefit from these exemptions, the implemented system (whether it is a certified EMS, ISO 14001 certification, or an EPC) must cover a significant portion of your energy consumption. The general rule is that at least 80% of your final energy consumption must be covered by the system. This ensures that the energy efficiency improvement initiative is comprehensive and not limited to a small part of your activities. Compliance with this threshold is therefore a key point for validating your exemption. Companies that already have an energy management system may thus be exempt.

Deadlines and Renewal of the Energy Audit

Deadline for Conducting the First Audit

For companies newly subject to the mandatory energy audit obligation, a deadline is generally given to carry out this initial diagnosis. This deadline is often linked to the date the regulation comes into force or the date the company exceeds the defined consumption thresholds. It is therefore essential to stay informed of legislative changes to anticipate this deadline. For example, new obligations apply to companies from 2025, detailing the thresholds and deadlines to be met [4847].

Frequency of Audit Renewal

The energy audit is not a one-off process. The regulation requires periodic renewal to ensure that the actions taken are effective and that energy consumption remains under control. The general rule is renewal every four years. This frequency allows for monitoring changes in energy uses and identifying new improvement opportunities. Failure to comply with this periodicity may result in penalties.

Deadline for Implementing a Certified EMS

An alternative to conducting regular energy audits is to implement a certified Energy Management System (EMS), for example, according to the ISO 50001 standard. Companies with such certification are exempt from the periodic mandatory energy audit obligation. This is because an EMS involves a comprehensive and continuous process of monitoring and improving energy performance. Companies already subject to an energy audit whose renewal is scheduled before 1 October 2025 must take specific measures to comply with the new requirements [643d].

Here is a summary table of the deadlines:

Situation	Renewal Frequency	Alternative
Mandatory energy audit	Every 4 years	Implementation of a certified EMS (ISO 50001)
Companies exceeding consumption thresholds	First audit according to deadline	Implementation of a certified EMS (ISO 50001)

It is important to note that the implementation of recommendations from the audit must take place within five years of its completion. This ensures that the identified energy savings translate into concrete actions.

Content and Methodology of the Energy Audit

Key Steps in Conducting an Audit

An energy audit cannot be improvised. It follows a structured process to ensure the reliability of results and recommendations. Here is generally how a statutory audit is conducted:

1. Data collection: Meticulous gathering of information on past consumption, invoices, technical inventory, and equipment.
2. Site visits and field surveys: Direct observation to validate data and identify actual uses.
3. Detailed technical analysis: Examination of installations and energy systems using measurement tools.
4. Modelling and calculations: Creation of a consumption model to simulate different improvement scenarios.
5. Development of a report and action plan: Summary of findings and quantified concrete proposals.

A seriously conducted audit serves as a real roadmap to quickly target accessible energy savings, based on facts and measurements.

Analysis of Significant Energy Uses

One of the essential parts of the audit involves a detailed examination of significant energy uses (SEUs). This includes:

• Identifying the most energy-consuming areas (production, utilities, buildings, transport, etc.).
• Assessing the performance of each process against industry best practices.
• Identifying malfunctions or energy-saving potential.

A relevant audit ensures that all SEUs are correctly measured, *not estimated*, with reliable and traceable records.

Identification and Prioritisation of Improvement Actions

After identifying how energy is consumed, the next step is to draw up a list of improvement actions and then rank them according to several aspects:

Proposed Action	Estimated Energy Saving (%)	Investment Cost (€)	Payback Period (years)
HVAC system optimisation	10	5,000	2
LED lighting renovation	8	7,000	2.5
Waste heat recovery	15	25,000	4

• Prioritise short, medium, and long-term measures.
• Analyse profitability via the payback period (PBP).
• Consider technical and organisational constraints.

An audit is not limited to providing an overview: it also assists the company in the concrete implementation of a structured action plan, designed to genuinely reduce energy expenditure in the long term.

Mandatory Energy Audit Report: Required Elements

Once the energy audit is completed, it is essential to formalise the conclusions in a detailed report. This document is the cornerstone of the process and must meet specific requirements to be compliant. It is not a simple summary, but a structured analysis aimed at guiding the company’s future actions.

General Information on the Company and Buildings

The report must first clearly present the context of the audit. This includes identifying the audited company, particularly its SIREN number, as well as information relating to the buildings concerned: their location, total area, and, if relevant, their primary use (offices, production, storage, etc.). It is also important to mention the specific activities that take place in these buildings, as they directly influence energy consumption. This first section lays the groundwork for understanding the study that follows.

Details of Consumption and Energy Types

This is the core of the report. It must contain a precise description of the observed energy consumption. This includes quantifying the different energy sources used (electricity, natural gas, fuel oil, etc.) and their breakdown by significant use. The objective is to understand where and how energy is consumed within the company. The data must be based on traceable measurements, not estimates, to ensure the reliability of the analysis. The cost of invoices associated with each type of energy must also be included, allowing for a direct link between consumption and financial costs. An analysis of the company’s vehicle fleet characteristics, if covered by the audit, is also required.

Recommendations for Actions and Profitability Analysis

Following the analysis of consumption, the report must propose concrete improvement measures. These recommendations must be prioritised based on their energy-saving potential and feasibility. For each suggested action, a profitability analysis is essential. This involves quantifying the implementation cost, estimating the expected annual energy savings, and calculating the payback period (PBP). The report may also mention the potential impact of the actions on the building structure or its architectural appearance. The goal is to provide the company with clear elements for making informed decisions regarding its energy efficiency investments. This document is a key step for any industrial energy performance improvement initiative, allowing compliance with a regulatory obligation while identifying real savings opportunities [e465].

The mandatory energy audit report must be transmitted electronically to ADEME. It serves as the basis for implementing improvement actions, which generally must be carried out within five years of the audit.

Organisations and Qualifications for Conducting the Audit

When it comes to conducting a mandatory energy audit, companies have several options. There is no single path, and the choice often depends on internal resources and the complexity of the company.

Possibility of Qualified Internal Auditors

It is entirely possible to use individuals within your own company to carry out this audit. However, these internal auditors must demonstrate solid skills in energy management. General knowledge is not enough; concrete experience and a deep understanding of energy issues must be demonstrated. Article 3 of the regulatory texts specifies the criteria that must be met for these personnel to be recognised as competent to conduct an energy audit. This option can be interesting for companies that already have dedicated energy efficiency teams, such as those working on implementing an energy management system.

Use of Specialised External Service Providers

For many companies, using a specialised external engineering firm is the preferred solution. These providers offer in-depth expertise and an impartial perspective. They are often familiar with the latest regulatory changes and industry best practices. An external audit professional can ensure that the audit meets the requirements for resources and skills, particularly those defined by the NF EN 16247 series of standards. These organisations are generally certified, which provides an additional guarantee of quality and compliance. It is important to verify that the chosen provider has the necessary qualifications, especially since COFRAC has stopped accrediting qualification bodies based on the old NF-X standard. Therefore, it is necessary to ensure that the provider is up-to-date with the new requirements, for example, by consulting lists of organisations recognised by public authorities.

Reference Standards for Auditors

The conduct of a mandatory energy audit is governed by specific standards, particularly the EN-16247 series. This European standard defines the general and specific requirements for conducting energy audits. It covers various aspects, from methodology to auditor qualifications. Auditors, whether internal or external, must comply with these standards for the audit to be recognised as valid. This includes how data is collected, consumption is analysed, and relevant recommendations are made. Compliance with these standards ensures a certain uniformity and reliability in the audits conducted across the country, and allows for comparison of energy performance between different entities.

Regulatory Framework for the Mandatory Energy Audit

Transposition of the European Directive on Energy Efficiency

The obligation for large companies to conduct an energy audit originates from the European Directive 2012/27/EU on energy efficiency. This directive has been incorporated into French law, notably by Law No. 2013-619 of 16 July 2013. The main objective is to encourage companies to assess and reduce their energy consumption. The DDADUE law (Law of 30 April 2025) has since updated these rules, modifying the eligibility criteria to focus on actual consumption rather than company size.

Relevant Articles of the Energy Code

Several articles of the Energy Code specify the application procedures for this obligation. These include:

• Article L.233-1, which establishes the principle of energy audits for large companies.
• Article L.233-3, which details the methodological requirements and qualifications required for auditors.
• Articles R.233-1 and R.233-2, which provide details on the thresholds and qualification criteria for affected companies.
• Article D.233-3, which sets the scope of consumption to be analysed, requiring coverage of at least 80% of the company’s energy expenditure for all its buildings.

EN-16247 Standard and its Requirements

The methodology for conducting the energy audit is governed by the European standard NF EN 16247. This standard defines the key steps and requirements to ensure the quality and comparability of audits. It states that the audit must be a structured analysis of significant energy uses, based on measured rather than estimated data. Since the order of 10 July 2025, data traceability is particularly emphasised. The standard also details the expected content of the audit report, including the identification of energy-saving potentials and their prioritisation according to the payback period (PBP). Recommendations must be quantified, thus allowing for a clear profitability analysis for the company. Compliance with this standard is therefore *fundamental* for the validity of the audit.

Penalties for Non-Compliance

Failure to comply with the obligation to conduct an energy audit can have significant financial consequences for companies. It is therefore important to fully understand the risks involved in case of non-compliance.

Amount of the Fine for Non-Completion

Companies that are subject to the mandatory energy audit obligation but have not carried it out are liable to a fine. The amount of this penalty can reach up to 2% of the company’s turnover excluding tax (HT), calculated on the basis of the last closed financial year. This is a substantial sum that can seriously impact a company’s finances.

Consequences in Case of Repeat Offences

If a company does not comply after being penalised, the authorities may impose stricter measures. In case of repeat offences, i.e., if the breach occurs again, the financial penalty can be doubled. It can then amount to up to 4% of the turnover excluding tax. It is therefore essential to take this obligation seriously from the outset to avoid such situations.

It is essential to consider the energy audit not as a constraint, but as an opportunity for optimisation. Financial penalties are there to remind us of the importance of this process for overall energy efficiency.

Companies must therefore ensure that they carry out their audit within the prescribed deadlines. For those exceeding consumption thresholds, it is advisable to find out about the steps to take to comply and avoid penalties. The law sets clear rules, and compliance with these rules is a condition for sound and responsible business management. Remember to consult the information available on the energy audit collection platform to ensure you fully understand all the requirements.

Link Between Energy Audit and Energy Management System

The Audit as the First Step of the EMS

The mandatory energy audit, as defined by the EN-16247 standard, represents an in-depth analysis of a company’s energy consumption. It is a structured process that identifies significant energy uses and proposes concrete improvement measures. This analysis often constitutes the ideal starting point for implementing an Energy Management System (EMS). By providing a precise map of energy flows and savings potential, the audit lays the necessary groundwork for developing a more comprehensive and sustainable energy management strategy. It helps to understand where and how energy is consumed, which is essential before effectively managing this consumption in the long term.

Exemption from Audit for ISO 50001 Certified Companies

The regulations provide recognition for voluntary initiatives aimed at excellence in energy management. Thus, companies that have implemented and certified an Energy Management System compliant with the ISO 50001 standard are generally exempt from conducting the mandatory energy audit every four years. This exemption is due to the fact that ISO 50001 certification involves a continuous process of improving energy performance, which often encompasses and exceeds the requirements of a one-off audit. A certified EMS guarantees a systematic and documented approach to energy management, including planning, implementation, monitoring, and review of energy performance. This ensures coverage of energy consumption comparable to, or even exceeding, that required by the mandatory audit. For more information on obligations, consult the information on new regulatory obligations.

Comprehensive Energy Management Approach

The link between the energy audit and the EMS is therefore one of synergy. The audit provides an instant and detailed snapshot, while the EMS establishes a dynamic and continuous process. It is not simply about meeting a one-off obligation, but about integrating energy management into the core of the company’s strategy. A well-designed EMS allows for continuous optimisation of energy performance, reduction of operating costs, and decrease of the environmental footprint. It fosters a corporate culture focused on efficiency and energy responsibility. The implementation of such a system, often initiated following an energy audit, represents a strong commitment to sustainable development and competitiveness. The energy audit is therefore a valuable tool for initiating or strengthening a *comprehensive* energy management approach, which goes far beyond simple regulatory compliance. It is a true strategy for better energy efficiency.

The energy audit and an energy management system are like two friends helping each other. The audit looks at where energy is going and how things can be improved, much like checking your school report card to see where you can do better. The management system, on the other hand, puts rules in place to ensure that efforts continue and energy is saved every day. Together, they help to spend less and be more respectful of the planet. Want to know more about how to manage your energy effectively? Visit our website to discover our solutions!

In Summary: A Beneficial Process Beyond the Obligation

In conclusion, the mandatory energy audit, while representing a regulatory constraint for certain companies, proves to be a valuable tool. It not only ensures compliance with the law but, more importantly, identifies concrete avenues for reducing energy consumption. This translates into significant financial savings and better cost control. Furthermore, by adopting a proactive approach, companies can improve their environmental impact, an aspect that is increasingly important for their image and competitiveness. Don’t forget that the recommendations from this audit must be implemented within five years, so it’s best to prepare for it now.

Frequently Asked Questions

Who absolutely must conduct an energy audit?

Companies that consume a lot of energy, more than 2.75 gigawatt-hours per year on average over three years, are affected. Previously, company size (number of employees, turnover) was also considered, but that is no longer the case. Consumption is now the deciding factor, regardless of the company’s size.

Are there cases where the audit is not mandatory?

Yes, if a company has already implemented a certified energy management system, such as the ISO 50001 standard, which covers at least 80% of its consumption. Other specific certifications or contracts may also exempt from the audit, provided they address a significant portion of the energy consumed.

When must the first energy audit be carried out?

Affected companies must have carried out their first energy audit by 11 October 2026 at the latest. If they prefer to implement a certified energy management system, they have until 11 October 2027 to do so.

How often must the energy audit be repeated?

The energy audit must be renewed every four years. This is a requirement to ensure that energy-saving efforts are maintained and that new improvement opportunities are identified regularly.

What must the audit report contain?

The report must provide clear information about the company, detail all energy sources used and their consumption. It must also propose concrete actions to save energy, explaining the cost and the time required to recoup the investment.

Who can conduct an energy audit?

A company can choose to conduct the audit with its own employees if they have the necessary skills. Otherwise, it can call upon companies specialising in energy efficiency. These professionals must be familiar with current standards, such as the NF EN 16247 series.

What are the rules that apply to energy audits?

The mandatory energy audit in France follows specific rules, particularly those defined by a European directive on energy efficiency. The French Energy Code details the obligations, the criteria for companies, and the requirements for auditors. The EN-16247 standard provides the methodological framework.

What happens if a company does not conduct its audit?

If a company subject to the obligation does not carry out its energy audit, it risks a fine. This fine can be up to 2% of its annual turnover. If the company still does not comply after a first penalty, the fine can be doubled to reach 4% of its turnover.