The EU energy audit obligation: who needs an audit or an energy management system

From company size to energy use

Under the old Energy Efficiency Directive, every large company had to carry out an energy audit every four years, whatever it used. The recast directive, Directive (EU) 2023/1791, changed the test. Article 11 now looks at how much energy a company uses: its average annual final energy consumption over the previous three years, across electricity, gas, heating oil, vehicle fuel and district heat together. A small company with a heavy process can now be in scope, and a large office company can fall out.

The two thresholds

Companies above 85 TJ a year, about 23.6 GWh, must run an energy management system, certified by an independent body, by 11 October 2027. Companies above 10 TJ, about 2.8 GWh, that do not have such a system must carry out an energy audit by 11 October 2026 and repeat it at least every four years. A company with a certified energy management system is not subject to the separate audit duty.

Member States had until 11 October 2025 to put this into national law, and several are late. Until a country has amended its law, its old rules can still apply, including a test based on company size. Check the national law for the exact dates, the authority and any reporting portal.

What an energy audit covers

Annex VI of the directive sets minimum criteria. An audit must be:

• Based on up-to-date, measured and traceable data on energy use, and on load profiles for electricity where available.
• A detailed review of the energy use of buildings, industrial processes and transport.
• Built on life-cycle cost analysis, so savings over the life of a measure count, not only the payback.
• Proportionate and representative enough to give a reliable picture of overall energy performance.
• Carried out independently by qualified or accredited experts, often following the EN 16247 series.

The action plan

The audit is not the end. Companies have to turn its recommendations into a concrete and feasible action plan and present it to management. The directive also requires the action plan and the share of recommendations carried out to be made public, for example in the annual report. The next audit four years later shows whether the measures were taken.

Counting your energy use

10 TJ is 2,778 MWh. Add up all final energy from a full year of invoices: electricity and gas in kWh, heating oil and vehicle fuel converted to kWh, and district heat. A litre of diesel holds about 10 kWh. A company that uses 1.8 GWh of electricity and 120,000 litres of diesel for its vans already uses about 3 GWh, above the audit threshold. Average three years, because one unusual year does not decide it.

Doing it in Greener Ahead

Greener Ahead does not carry out energy audits. Carbon accounting in Greener Ahead records your energy use per site and energy carrier from invoices and meter readings, totals it in kWh, which shows where you stand against the thresholds, and turns it into Scope 1 and 2 emissions. Comparing every year with the last shows whether the audit’s measures worked. It costs €1,495 per year with unlimited users, and you can try it free for 14 days without a card. Check the pricing page for current details.

Thresholds at a glance

Article 11 of Directive (EU) 2023/1791.

Before the auditor arrives

These preparations make the audit faster and more useful.

• Collect three years of energy invoices per site and energy carrier.
• Gather interval data for electricity where your supplier or meter provides it.
• List the main energy users: furnaces, compressors, cooling, ventilation, lighting, vehicles.
• Note production volumes per year, so energy can be compared per unit.
• Agree who in management will receive and approve the action plan.