Energy Performance Certificate (EPC): Coénove contests the new reduction in the electricity conversion coefficient

The electricity conversion factor used in energy performance diagnoses (EPCs) and energy audits will change from 1,9 to 1,7 on January 1, ^2027. This new value was approved by a decree of August 19, 2026, published in the Official Journal on August 26.

The decision comes a year after an initial reduction, from 2,3 to 1,9, which came into effect on January 1, ^2026. It is generating new criticism among energy renovation stakeholders, including the Coénove association, which denounces a growing instability in the DPE calculation method.

What is the purpose of the conversion factor?

The coefficient allows us to convert the electricity consumed in a dwelling, called final energy, into primary energy. The latter conventionally includes the energy used to produce and transport the electricity to the building.

With a coefficient of 1,9, a standard electricity consumption of 100 kWh per square meter corresponds to 190 kWh of primary energy. From 2027 onwards, this will be calculated at 170 kWh. All other things being equal, the primary energy consumption recorded in the Energy Performance Certificate (EPC) will therefore decrease for homes using electricity.

This change will not alter the building's actual energy consumption, insulation, comfort, or the occupant's energy bill. It only affects the regulatory conversion used to calculate the energy label. The greenhouse gas emissions label will remain unchanged.

A choice intended to support electrification

The Government includes this decision in its plan for the electrification of energy uses. It considers that the previous coefficient penalized homes heated by electricity compared to those using gas or fuel oil, whose conversion factor remains fixed at 1, even though the French electricity mix has a relatively low carbon intensity.

The proposal presented during the public consultation indicated that this reduction should support the phase-out of fossil fuels in buildings and better reflect decarbonization objectives. The European framework allows Member States to use the European factor or to adopt a national value adapted to their energy system.

The Federation of Electrical, Electronic and Communication Industries notably supported this approach. It believes that the reduction mitigates a regulatory disadvantage imposed on electricity and increases the value of electrical equipment, particularly heat pumps and thermodynamic water heaters.

Nearly 300.000 energy-inefficient homes could be upgraded to a new energy efficiency class.

According to the impact study presented as part of the project, reducing the energy performance ratio from 1,9 to 1,7 would move nearly 300.000 primary residences out of energy efficiency classes F and G, representing approximately 10% of the identified energy-inefficient homes. Nearly 200.000 dwellings would move out of energy efficiency class F and 100.000 out of energy efficiency class G.

In the private rental sector alone, approximately 125.000 homes could be reclassified as energy inefficient. This reclassification would have significant regulatory consequences for landlords, as the energy performance certificate (EPC) rating gradually determines whether certain properties can be rented.

These label changes will take place without any work being carried out. Therefore, they do not mean that heat loss, final energy consumption, or energy costs for the affected dwellings will have decreased.

Coénove fears a weakening of the renovation sector

Coénove believes this further reduction could discourage some homeowners from undertaking work on the building envelope. The association argues that a property reclassified solely due to the change in the calculation method may lose some of the regulatory and economic incentive to carry out renovations.

She also disputes the method used to set the value of 1,7. According to her own analyses, a calculation based on the current and prospective characteristics of the French electricity system would lead to a value greater than 2,3. However, this estimate is not included in the regulatory documents published by the Government.

Coénove also warns about the successive changes to the coefficient, which complicate the understanding of the Energy Performance Certificate (EPC) for owners, tenants, and buyers. The same property can indeed receive a new rating even though its technical characteristics and conventional final energy consumption have not changed.

A highly contested public consultation

The draft decree was subject to a public consultation from July 9 to August 6, 2026, which gathered 110 contributions. Numerous construction, engineering, and insulation organizations expressed their opposition, while several representatives of the electrical sector supported the reform.

The decree also mentions the opinions issued by the High Council for Energy on July 23 and by the High Council for Construction and Energy Efficiency on July 31. However, the text published in the Official Journal does not specify the content of these opinions.

According to Jean-Charles Colas-Roy, president of Coénove: "After 2,3, then 1,9, now we have 1,7. How far will this go? By constantly modifying scientific indicators to artificially improve statistics, we end up losing sight of the main objective: to actually renovate housing."

According to him, a change in the coefficient alone cannot reduce consumption, bills, or energy poverty. The association demands that any changes to the Energy Performance Diagnosis (DPE) method be based on a publicly available, stable, and objectively justified methodology.

A free certificate for existing EPCs

Valid Energy Performance Certificates (EPCs) and energy audits will be able to benefit from the new calculation without requiring a new assessment by a certified professional. From January 1, ²⁰²⁷ , a certificate of change in energy rating will be available for free download from the ADEME's EPC-Audit Observatory.

This certificate will replace the original label without altering the input data, the property characteristics, or the audit work scenarios. Its validity period will end at the same time as that of the original document.

In the absence of a request for certification, the DPE or the initial audit will remain valid until its expiry with the label it currently has.