DPE Reform for Properties Under 40 m²

Since July 1, 2024, the Energy Performance Certificate (Diagnostic de Performance Énergétique or DPE) reform in mainland France has introduced adjusted energy rating thresholds for properties with a reference floor area of 40 m² or less. The reform aims to correct calculation biases that previously disadvantaged some smaller homes, particularly due to the disproportionate impact of domestic hot water consumption relative to their floor area. Approximately 140,000 properties were expected to move out of the least energy-efficient categories, F and G, as a result of this reform. Owners of eligible properties can obtain a free updated energy rating certificate through the French Agency for Ecological Transition (ADEME) online DPE-Audit Observatory by entering their existing DPE identification number, without commissioning a new energy assessment. Since January 1, 2026, the electricity primary energy conversion coefficient has also been reduced from 2.3 to 1.9. A further change, scheduled for January 1, 2027, will lower this coefficient from 1.9 to 1.7, potentially improving the energy ratings of additional electrically powered properties. These updated certificates do not extend the validity of the original DPE. For landlords, these changes are particularly important because of France's progressive energy efficiency requirements for rental properties: G-rated properties have been subject to rental restrictions since January 1, 2025, followed by F-rated properties from January 1, 2028, and E-rated properties from January 1, 2034, subject to applicable legal conditions and exceptions.

On July 1, 2024, a reform of the Energy Performance Certificate (Diagnostic de Performance Énergétique or DPE) came into effect in mainland France to better account for the specific characteristics of properties measuring less than 40 m². In particular, it adjusted energy rating thresholds to correct calculation biases that disadvantaged some smaller properties, especially due to the impact of domestic hot water production on their energy consumption.

Why was a DPE reform necessary?

The need to reform the DPE for properties measuring less than 40 m² arose primarily from inequalities identified in the assessment of their energy performance.

Indeed, the previous DPE calculation method disadvantaged certain small properties, sometimes classifying them as highly energy-inefficient homes. Domestic hot water consumption was identified as a major issue because its relative impact was often disproportionate when compared with the property's floor area.

New DPE energy rating thresholds

Since July 1, 2024, DPE energy rating thresholds have been adjusted for properties with a reference floor area of 40 m² or less.

This change better reflects the energy characteristics of smaller properties and has enabled some of them to achieve an improved energy performance rating.

According to estimates published when the reform was introduced, approximately 140,000 properties were expected to move out of the least energy-efficient categories (F and G), making energy performance assessments fairer.

Furthermore, since January 1, 2026, the conversion coefficient used to calculate primary energy consumption from electricity has been reduced from 2.3 to 1.9.

A further change will take effect on January 1, 2027, when this coefficient will be reduced from 1.9 to 1.7. Properties using electricity, particularly for heating, may therefore benefit from an improved energy rating, depending on their characteristics.

How can you update your DPE?

Since July 1, 2024, owners of properties with a reference floor area of 40 m² or less can obtain an updated DPE energy rating certificate, provided their existing assessment is eligible.

This process is free and can be completed online through ADEME's DPE-Audit Observatory. Simply enter the identification number of your property's current DPE to check its eligibility and download the updated certificate, without having to commission a new energy performance assessment.

DPE validity and consequences for landlords

The certificate generated to update a property's energy rating does not extend the validity of the original DPE. It simply reflects the regulatory changes applicable to the calculation of the property's energy performance rating.

For landlords, the energy performance rating of their property is particularly important because of the progressive restrictions on renting out the least energy-efficient homes in mainland France:

• Since January 1, 2025: G-rated properties no longer meet the energy efficiency requirements for decent rental housing;
• From January 1, 2028: F-rated properties will also be affected;
• From January 1, 2034: E-rated properties will become subject to the same requirements.

These deadlines apply under the conditions established by French regulations, particularly for new rental agreements and relevant lease renewals, with certain legal exceptions.

The successive DPE reforms introduced since 2024 have significantly changed the energy ratings of certain properties, especially smaller homes and those using electricity.

By taking the specific characteristics of these properties into account, the reforms help make DPE assessments fairer and more accurate.

Landlords should therefore regularly check whether their property is eligible for an updated energy rating, particularly as the next regulatory deadlines approach.

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