The mandatory energy audit: what changes on 11 October 2026.
In France’s reform of the energy audit, the heaviest part comes after the audit. A company will have to publish an action plan, and its completion rate with it. For an energy manager, that means tracking, action by action, what the plan actually saves. The rest has changed too: the obligation now depends on consumption, from 2.75 GWh a year, and newly covered companies have until 11 October 2026 for their first audit.
The criterion is no longer size but consumption.
Until now, the mandatory audit applied to large companies, under a 2012 directive. French law no. 2025-391 of 30 April 20251, in force since 1 October 2025, changed the rule, and decree no. 2025-1382 of 29 December 20252 set out the details.
The French Ministry for the Ecological Transition3 sets two thresholds. From 2.75 GWh a year, it is an energy audit every four years. From 23.6 GWh, an energy management system (EnMS) certified to ISO 50001.
The figure used is the average of the last three calendar years, so 2023, 2024 and 2025 for an assessment made in 2026. And it covers everything: buildings, industrial processes, transport, including renewable energy generated and consumed on site, according to the DREAL Bretagne, the French state’s regional environment directorate for Brittany.
To put the threshold in perspective: 2.75 GWh is an average load of about 314 kW drawn day and night, all year round. A furnace, a compressed air plant and a few chillers can be enough.
A published action plan, and so a tracked one.
The law now requires an action plan drawn from the audit’s recommendations. A measure that pays back in under five years and is not implemented has to be justified. The approved plan is published in the annual report, with its completion rate.
According to the ministry, the recommended investments can deliver savings of up to 30% depending on the activity. With the plan made public, it is better to be able to check that figure on your own meters.
The audit results are submitted on the platform run by ADEME4, the French agency for ecological transition, along with the consumption declaration, and the DREALs check the supporting documents. In the event of a breach, the authorities serve the company with a formal notice, publicly if they so choose. If nothing changes within the set time, the fine can reach 2% of turnover excluding tax, and 4% for a repeat offence.
The measurements are often already there, in pieces.
The audit must cover at least 80% of the final energy consumption of the company, identified by its SIREN number (its French company registration number), using a method set by the order (arrêté) of 10 July 2025. On a site that has been equipped layer by layer, that 80% is rarely in a single file.
It is in the supplier’s bills. In sub-meters fitted at different times, by different installers. In PLCs that have counted a compressor’s running hours since it was commissioned. And in the readings your teams write down by hand on their rounds.
We saw it on fuel oil tanks, at a thermal power plant operator we equip. Their 4-20 mA level probes only displayed their readings locally. A converter turned them into Modbus TCP, the BOX sends them over 3G/4G, and consumption is now read off the chart, with a high-level alarm before any overflow. The measurement existed. It simply never left the tank.
That is the work we do for an energy manager: reading the meters, PLCs and sensors already in place, fitting a sensor where nothing is measuring, and filing all these measurements in a single history, in consistent units, alongside the readings kept in a spreadsheet. Trends and tables can then be exported as files for the audit, and your reporting tools can retrieve the data through the API.
A pulse output on an old meter, an energy register in a PLC, a value written down on paper every week: all of it can feed the audit, then the tracking of the action plan. The weak point, often, is continuity. A once-a-year reading will never tell you whether the variable speed drive fitted in March has lived up to its promise.
Frequently asked questions.
Is an audit carried out in-house accepted?
Yes. The French Energy Code allows either a qualified external provider or an employee of the company, provided the employee is not directly involved in the audited activity on the site, the DREAL Bretagne points out.
Does ISO 50001 certification exempt a company from the audit?
Yes, if a certified EnMS covers all the activities in scope. A certified ISO 14001 system that includes a compliant audit, or an energy performance contract, can also qualify for an exemption, subject to conditions. For your specific situation, your DREAL remains the point of reference.
Sources.
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DREAL Bretagne, presentation of the changes to energy efficiency legislation (law no. 2025-391, deadlines, action plan, penalties), 6 January 2026.
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Décret n° 2025-1382 du 29 décembre 2025 relatif à la transposition de la directive (UE) 2023/1791, on AIDA (INERIS).
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French Ministry for the Ecological Transition, page on the energy audit for companies, 1 October 2025.
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ADEME, platform for submitting energy audits.
