Carbon footprint, CSRD, Tertiary Decree: which decarbonisation obligations apply to your organisation in 2026?

A stack of obligations that is hard to read

Real estate, finance and sustainability teams face a dense regulatory landscape: greenhouse gas assessments, European sustainability reporting, energy reduction pathways for commercial buildings, energy audits, building automation requirements. Each obligation has its own scope, timeline and reporting platform.

The good news is that these texts largely rely on the same data: energy consumption, floor areas, uses, emissions. Properly mapped, they can be handled in a single process rather than five parallel projects. You still need to know which ones apply to you.

The regulatory GHG assessment (BEGES): the broadest obligation

Under article L229-25 of the French Environmental Code, a greenhouse gas emissions assessment is mandatory for companies with more than 500 employees (250 in overseas territories), local authorities with more than 50,000 inhabitants, the State and public bodies with more than 250 staff.

It must be updated every four years for companies (every three years for public bodies) and published on the ADEME platform. Since 2023, it must include significant indirect scope 3 emissions — purchasing, freight, travel, product use — and be accompanied by a transition plan setting out planned reduction measures. Failure to publish exposes the organisation to an administrative fine.

In practice, scope 3 often represents most of the footprint, and requires the most data collection work.

CSRD after the Omnibus: a narrower scope

The EU Corporate Sustainability Reporting Directive (CSRD) was originally set to cover around 50,000 European companies. The "Omnibus" simplification package launched by the European Commission in February 2025 has substantially revised both its timeline and scope.

A first "stop-the-clock" directive, adopted in spring 2025, postponed by two years the obligations of companies that had not yet started reporting. The political agreement reached at the end of 2025 then refocuses the obligation on companies with more than 1,000 employees and more than €450 million in turnover, with simplified reporting standards (ESRS).

Two points remain essential for organisations that fall outside the scope. First, their large in-scope customers will keep asking them for carbon data for their own value chain reporting, within the limits set by the voluntary standard for SMEs (VSME). Second, banks and investors increasingly factor these indicators into their financing decisions.

As transposition timelines are still evolving, we recommend checking your exact situation before committing a reporting budget.

The French Tertiary Decree: a quantified pathway, building by building

The Tertiary Decree (Éco Énergie Tertiaire) applies to buildings, parts of buildings or groups of buildings in commercial or public use of 1,000 m² or more. Owners and occupiers must reduce final energy consumption by 40% by 2030, 50% by 2040 and 60% by 2050 compared with a reference year after 2010, or reach a threshold expressed in absolute terms.

Consumption must be reported every year on the OPERAT platform, before 30 September. Adjustments are possible (technical or architectural constraints, disproportionate costs), provided they are justified in a technical file. Non-compliance may lead to public disclosure ("name and shame") and administrative fines.

This is the obligation most directly linked to renovation works — and therefore to funding through Energy Efficiency Certificates.

The BACS Decree: controlling technical systems

The BACS Decree requires building automation and control systems in commercial buildings for heating, air-conditioning and ventilation installations above certain power thresholds. Systems above 290 kW were targeted first; the obligation then extends to systems above 70 kW, on a timeline that has been relaxed.

Beyond compliance, a building management system is one of the most cost-effective levers under the Tertiary Decree: it often delivers 10 to 20% savings on the systems it controls, and several standardised EEC operations fund part of the investment.

Regulatory energy audits: a consumption-based criterion

The recast EU Energy Efficiency Directive is changing mandatory energy audits: the historical company-size criterion is giving way to an energy consumption criterion. Organisations above certain consumption thresholds must carry out an audit every four years, and the largest consumers must implement an ISO 50001-type energy management system.

This change mainly affects industrial sites and large commercial portfolios. It further aligns energy audits with other obligations: the data collected also feeds the GHG assessment, OPERAT and, where applicable, CSRD reporting.

SBTi: voluntary, but increasingly expected

The Science Based Targets initiative is not a legal requirement. It has nevertheless become a de facto standard: many large buyers require suppliers to set reduction targets aligned with the Paris Agreement, validated by or at least built on this method. An SBTi target covers actual emission reductions; carbon credits do not count towards it.

Where to start

Map your obligations. Headcount, turnover, commercial floor area, energy consumption, public or private status: these few criteria are enough to list what applies to your organisation, and by when.

Pool your data. A single inventory of consumption and floor areas feeds OPERAT, the GHG assessment, the energy audit and non-financial reporting alike. This is the biggest time saver.

Build a single pathway. Rather than responding text by text, a decarbonisation pathway prioritises actions by impact and cost, and sets milestones that address all obligations at once.

Fund the actions. A large share of energy efficiency works is eligible for Energy Efficiency Certificates. Planning for their monetisation before signing quotes often changes the economics of the action plan.

Review your obligations with Kilowater: we clarify your regulatory position and the most effective pathway to meet it.