Since the DDADUE law (French Law No. 2025-391 adapting French law to EU law), your company's energy consumption alone decides whether you must set up an EnMS. Above 10 TJ a year, the energy audit is mandatory. Above 85 TJ, an energy management system (EnMS) is expected by October 2027. The approach also aims to cut energy costs and environmental impact. One condition decides everything: an EnMS is only as good as the building's data.
What an energy management system is, and what it is not
A continuous improvement approach written into the French Energy Code
The energy management system (EnMS; called SMÉ in France, sometimes written SMEn) is a continuous improvement approach, not software. The French Energy Code (Code de l'énergie) describes it as a process that helps a company progress by analyzing its consumption[1][1]RegulationLégifrance, French Energy Code (Code de l'énergie), art. L233-1See in sources ↓. It follows the PDCA cycle, the core of energy management as formalized by ISO 50001[2][2]Standards and protocolsISO, “ISO 50001 - Energy management”, 2011 and 2018 editionsSee in sources ↓. Its measurable goal: improving the energy performance of energy uses.
EnMS and ISO 50001: are they the same thing?
Not quite. EnMS refers to the approach; the ISO 50001 standard sets its certification requirements. It shares its structure with ISO 9001 and ISO 14001, which makes integration easier.
What is the difference between an EnMS and an EMS?
The EnMS organizes decisions. EMS software collects readings and flags drifts. Connected to silent meters, it will tell you nothing about the actual site. An EMS equips the approach; it does not replace it.
Mandatory or voluntary: what an EnMS requires and what it changes for a commercial portfolio
From a size criterion to a consumption criterion: what the DDADUE law sets
The 250-employee threshold is gone. The DDADUE law transposes Directive 2023/1791 into French law and uses average annual energy consumption over three years[3][3]RegulationEuropean Union, “Directive (EU) 2023/1791”, art. 11, transposed by Law No. 2025-391 of 30 April 2025 (DDADUE law), art. 25See in sources ↓. Above 2.75 GWh a year, or about 10 TJ, a company without an EnMS carries out an energy audit every four years. Above 23.6 GWh, or 85 TJ, it must have a certified EnMS by 11 October 2027 at the latest[3][3]RegulationEuropean Union, “Directive (EU) 2023/1791”, art. 11, transposed by Law No. 2025-391 of 30 April 2025 (DDADUE law), art. 25See in sources ↓. This consumption criterion applies to commercial buildings and industry alike, all sites included.
ISO 50001 certification exempts you from the regulatory energy audit
An EnMS with ISO 50001 certification, issued by an accredited body, exempts you from the energy audit. Article L233-1 of the French Energy Code provides for this equivalence[1][1]RegulationLégifrance, French Energy Code (Code de l'énergie), art. L233-1See in sources ↓. Above 10 TJ, certification offers an alternative: an annual check replaces a one-off audit.
What the EnMS does not replace: the Décret tertiaire and the BACS decree
A certified EnMS does not exempt you from the Décret tertiaire (France's tertiary decree on energy savings in commercial buildings), whose targets of -40% in 2030 to -60% in 2050 are reported on OPERAT, the French government reporting platform[4][4]RegulationLégifrance, “Decree No. 2019-771” (Décret tertiaire)See in sources ↓. The BACS decree (French decree 2020-887 on building automation and control systems) requires a BMS capable of hourly monitoring by zone[5][5]RegulationLégifrance, French Construction and Housing Code (Code de la construction et de l'habitation), art. R175-3See in sources ↓. It has applied since 2025 above 290 kW, with the 70-290 kW band postponed to 2030[6][6]RegulationLégifrance, “Decree No. 2025-1343 of 26 December 2025”See in sources ↓.
Is your organization concerned?
The law looks at your consumption, not your headcount. The three questions below tell you where you stand under the DDADUE law.
Energy audit or EnMS: where does your company stand?
Hesitating over the first question often betrays meters unable to provide the reference consumption. Sort this out before any regulatory choice.
Does an uncertified EnMS make sense?
Yes. Below the thresholds, setting up an EnMS makes sense if the readings hold up. A voluntary approach structures trade-offs and can be certified later. The classic trap remains the binder nobody opens: an EnMS that relies on unverified meters produces procedures, not savings.
Energy performance that no longer drifts from one year to the next
Without monitoring, energy drift sets in. A VIP complaint, such as the director who demands 24 °C all year round, gets settled with a manual override that is never lifted. The EnMS tracks down these deviations so that savings last.
Energy savings and greenhouse gas emissions falling together
In France, more than 50% of energy consumption still comes from fossil fuels[7][7]Bodies and institutionsAFNOR, “Energy management system” (Système de management de l'énergie)See in sources ↓. Every kWh avoided therefore cuts both a cost and a greenhouse gas emission. Energy savings are read in kWh, then in tCO2e for CSR reporting.
An energy policy driven by top management, aligned with ISO 14001
The energy policy commits the CEO, not just the energy manager. Backed by ISO 14001, it joins the environmental management system already being audited. At group level, responsibility is assigned site by site instead of being diluted between owner, FM and maintenance contractor.
Setting up an EnMS in 5 steps
Step 1: secure top management commitment and appoint an energy lead
An EnMS starts with the CEO's signature, which sets a quantified target and frees up resources. The CEO then appoints an energy lead, often an energy manager, who is accountable for the project. Depending on needs, training or outside support can help fill missing skills.
Step 2: carry out the energy review and identify significant energy uses
The energy review analyzes consumption by site to identify the uses that weigh the most. The following table compares the requirements of ISO 50001 with the reality of a commercial building.
| ISO 50001 requirement | Source in the building | What breaks | The test to run |
|---|---|---|---|
| Energy review | Meters in the supervision system | Disconnected or duplicate meters | Reconcile sub-meters with the main meter |
| SEU | HVAC and lighting sub-metering | Use not isolated | One meter per major use |
| EnB | Archived histories | Gaps in history | Count the days without readings |
| EnPI | Consumption, HDD, occupancy | Invisible manual overrides | List the overridden points |
| Monitoring | Alarms and reports | Ignored alarms | Open last month's log |
If two tests out of five fail, your significant energy uses (SEUs) rest on wrong figures.
Take action. Before drafting your energy review, have every meter and every overridden point tested by a BMS advisory firm independent of your integrator.
Step 3: fix the energy baseline and choose the EnPIs
The energy baseline (EnB) fixes a period against which every saving will be compared. A raw energy performance indicator (EnPI) proves nothing against a mild winter. Three indicators dominate:
- HDD-normalized EnPIs: kWh/m² per year, weather-corrected
- Heating kWh per heating degree day (HDD)
- Power demand outside occupancy hours
Step 4: build the action plan, making data reliable before optimizing
The action plan follows a simple order: make reliable first, optimize second. Meters get repaired and manual overrides get lifted before any setpoint is touched. This order makes every optimization verifiable. Heavy works come last, with possible funding through CEE energy-savings certificates (certificats d'économies d'énergie).
Did you know? CEE sheet BAT-TH-116 funds class A or B systems[8][8]RegulationFrench Ministry for Ecological Transition, CEE standardized operation sheet BAT-TH-116See in sources ↓, whereas the BACS decree sets its functional requirements without imposing any class.
Step 5: implement, monitor and review
The internal audit compares how installations are actually run with the written procedures. The management review then compares the EnPIs with their targets. After a change in how the premises are used, the EnB must be updated.
Equipping and certifying an energy management system: demonstrating improvement rather than declaring it
What a tool must do: collect, normalize, alert
An energy management solution collects meter readings, normalizes consumption by HDD, flags drift and produces the annual report. Its limit: the EMS observes without acting on any equipment.
BMS, EMS and hypervisor: who measures and who acts on the equipment?
The EMS detects the drift, the BMS corrects it by writing setpoints to the AHUs, valves and pumps. The hypervisor aggregates several sites without acting.
Spreadsheet, EMS or multi-site platform: choosing by portfolio size
Three criteria are enough: number of sites, available metering and write access to the controls. Managing a single site works with a rigorous spreadsheet. Beyond that, an EMS automates data collection, then a multi-site platform takes over for a group. Compare the number of reliable meters before the number of features.
How ISO 50001 certification works, from the initial audit to the three-year cycle
An accredited body first audits the documentation, then the site. The certificate is valid for three years, with annual surveillance audits[9][9]Standards and protocolsISO/IEC 17021-1, audit and certification of management systemsSee in sources ↓. Foobot does not certify anyone: our role stops at the quality of the readings examined.
What ISO 50003 asks the auditor to check
ISO 50003 requires a demonstrated improvement in energy performance[10][10]Standards and protocolsISO 50003, certification of energy management systemsSee in sources ↓. The auditor asks for the EnPIs, the EnB and the readings that link them. Without a justified deviation, a flawless manual is not enough.
Proving the saving: HDD-adjusted baseline and the IPMVP protocol
In practice, the auditor expects two overlaid curves over twelve months: the HDD-adjusted baseline and the metered consumption. The diagram below shows the principle.
HDD-adjusted baseline vs measured consumption, over 12 months
The gap between the two curves is the only auditable material. The IPMVP protocol sets the adjustment method[11][11]Standards and protocolsEVO, « International Performance Measurement and Verification Protocol (IPMVP) »See in sources ↓, ISO 50015 the verification principles[12][12]Standards and protocolsISO 50015, measurement and verification of energy performanceSee in sources ↓. At Valeo, HVAC consumption fell by 28.6%, measured under this protocol[13][13]Field feedbackValeo case study, HVAC consumption measured according to the IPMVP protocolSee in sources ↓. Even so, a building's potential is quantified after an audit.
What Foobot brings to an EnMS: reliable data and setpoints that hold
Making meters reliable before the energy review, with BMS advisory
Our BMS advisory engagement starts with a point-by-point audit of the meters in the supervision system. The deliverable lists each meter, its status and the fix required. Your analysis of energy uses then rests on figures you can defend.
Lifting manual overrides and putting operating sequences back in order
Overrides (manual overrides) pile up complaint after complaint, for lack of clear responsibility between operator and maintenance contractor. We list them, then restore consistent sequences without touching the safety of the installations.
Controlling HVAC with AI Control and AI Optimal Start when complexity justifies it
In a thermally complex building, AI Control regulates HVAC every 15 minutes from a digital twin. AI Optimal Start recalculates the restart time for each zone every day. Savings are verified with IPMVP. If a simple sequence is enough to optimize the site, we say so.
Before structuring an EnMS, check what your meters measure
Built on unverified readings, an EnMS produces reports, then a drift nobody sees. Made reliable first, it makes every euro invested serve a real cut in energy consumption.
Your next step: check what your meters measure, then compare their histories with your baseline.
FAQ - energy management system
What is the ISO 50001 standard?
ISO 50001 is an international standard that sets the requirements for an energy management system. Published in 2011 and revised in 2018[2][2]Standards and protocolsISO, “ISO 50001 - Energy management”, 2011 and 2018 editionsSee in sources ↓, it shares its structure with ISO 14001, which makes it easier to integrate with environmental management.
What is an energy management system?
It is another name for the energy management system (EnMS, SMÉ in French): a continuous improvement approach, not software. Policy, analysis of energy uses, EnPIs, energy baseline and action plan are reviewed every year following the PDCA cycle.
What are the main steps for implementing an energy management system in the commercial building sector?
An EMS equips the approach without replacing it. The steps remain those of the EnMS: secure the CEO's commitment, carry out the energy review, fix the baseline, build the action plan, then monitor. Making meters reliable remains the deciding factor.
How do I identify the best technology solutions to reduce my company's carbon footprint?
Start from the uses that emit the most greenhouse gases before launching works. Reliable metering helps quantify each low-carbon lever in your CSR strategy. A technology installed on wrong readings proves no reduction.
How do you certify an EnMS?
Have your EnMS audited by an accredited body, which issues ISO 50001 certification for three years. The auditor requires a demonstrated improvement in energy performance, backed by normalized EnPIs. This quantified evidence also secures you in case of an inspection.
What tools are there for energy management?
Three families of tools coexist: the spreadsheet, the EMS and the multi-site platform. The right choice depends on the number of sites, the available metering and write access to the controls. An oversized tool is pointless on a single site.
How long does it take to set up an EnMS?
The time needed to set up an EnMS depends mainly on the state of the meters. Clean histories shorten the initial analysis; gaps lengthen it. Starting with a meter audit lets you estimate this time before setting a schedule.
Sources and references
13 sources.- [1]Légifrance, French Energy Code (Code de l'énergie), art. L233-1↑ 1 2
- [3]European Union, “Directive (EU) 2023/1791”, art. 11, transposed by Law No. 2025-391 of 30 April 2025 (DDADUE law), art. 25↑ 1 2
- [4]Légifrance, “Decree No. 2019-771” (Décret tertiaire)↑
- [5]Légifrance, French Construction and Housing Code (Code de la construction et de l'habitation), art. R175-3↑
- [2]ISO, “ISO 50001 - Energy management”, 2011 and 2018 editions↑ 1 2
- [9]ISO/IEC 17021-1, audit and certification of management systems↑
- [10]ISO 50003, certification of energy management systems2021↑
- [11]EVO, « International Performance Measurement and Verification Protocol (IPMVP) »↑
- [12]ISO 50015, measurement and verification of energy performance↑
- [13]Valeo case study, HVAC consumption measured according to the IPMVP protocol↑