DPE: A "Still Immature" Tool at the Heart of Controversy – Particular Impact in Savoie and Haute-Savoie

The Court of Auditors delivers a harsh assessment of the Energy Performance Certificate in a report published on June 3, 2025, revealing major dysfunctions that compromise the credibility of this tool, which has become central to French energy policy. This issue is particularly concerning in the Two Savoys, where the specificities of the mountain real estate stock amplify the difficulties.

An Alarming Anomaly Rate of 70%

The scale of the problem is striking: nearly 70% of anomalies in EPCs carried out in 2023 by specialized companies, according to controls carried out by the General Directorate for Competition, Consumer Affairs and Fraud Prevention (DGCCRF). These anomalies mainly concern information defects on prices, failures to comply with consumer law, non-compliance with the legal cooling-off period or the presence of abusive clauses in contracts.

"Major" Consequences on the Real Estate Market

Pierre Moscovici, First President of the Court of Auditors, does not mince words: "The ban on renting depends directly on the implementation of the EPC and has major consequences on the property situation and the real estate market in general." This reality translates into worrying figures: the stock of properties for rent would have fallen by 22% for housing classified A to D between mid-2021 and mid-2023, and by 33% for housing classified F and G.

The financial impact on property owners is considerable. According to several recent studies, the energy label can vary the value of a property by up to 28%, or more than €1,000/m² in certain areas. A poorly classified housing can lose between 10% and 20% of its value on resale - a major issue for mountain real estate where heritage stakes are particularly important.

A Particular Challenge for the Two Savoys

Alpine territories face specific challenges. In Savoie and Haute-Savoie, the situation is particularly concerning: a mapping published in 2022 by Ademe indicates a thermal sieve rate of 28% in Savoie and 26% in Haute-Savoie, figures well above the national average of 15%. These departments "appear as poor students, due to the substantial number of mountain housing."

In the social housing sector, the figures are eloquent: Halpades, manager of 18,400 social housing units in Haute-Savoie, counts 1,594 housing units classified F and G. At Opac Savoie, the department's leading landlord with 22,000 housing units, 6,300 housing units (F, G, E) require renovation, representing an investment of 75 million euros until 2032.

Mountain real estate is particularly affected: 37.8% of mountain apartments and chalets will be banned from rental in 2028 and 76% in 2034 if owners do not renovate their housing. In Alpine ski resorts, 31% of housing are thermal sieves (F or G labels) compared to 15% in all metropolitan municipalities.

An Uncontrolled Explosion of the Sector

The EPC has experienced exponential growth: since 2018, the number of EPCs has tripled, from 120,000 to 350,000 diagnoses per month today. This massification is accompanied by a 46% increase in the number of certified real estate diagnosticians between 2019 and 2023.

This rapid growth has generated quality problems. David Rodrigues, lawyer at CLCV (consumer defense association), explains: "Every year, you have studies that show that the same housing is subject to different classifications, depending on the diagnostician who comes."

Questionable Calculation Methods

The Court of Auditors points to the methodological weaknesses of the system. The conditions under which these measurements or observations are made can, however, taint the result with uncertainties: limited time, pressure possibly exerted by owners, lack of supporting documents and insufficient training of diagnosticians.

Even more concerning, the "3CL-DPE" calculation method of the EPC effective since 2021, is a real mess. It remains incomprehensible for professionals as well as for the administration. The Court of Auditors report reveals that a parametric study was launched in autumn 2024 to "determine the weight of each parameter on the final score" of the housing.

The Specific Problem of Electric Heating in Mountains

A textbook case perfectly illustrates the system's aberrations in the Alps: "For two strictly identical housing units with the same insulation and the same technical characteristics, the gas-heated housing that emits 227 grams of CO2 per kWh will obtain a much better EPC score than the electrically heated housing that emits only 40 g of CO2 per kWh at most and which will be considered an energy sieve."

This situation particularly penalizes mountain housing in Savoie and Haute-Savoie, where electric heating is commonly used, especially in second homes and seasonal rentals. The application of the coefficient of 2.58 for electricity artificially transforms properly insulated housing into thermal sieves.

Structural Conflicts of Interest

The Court of Auditors denounces that "many training and certification organizations have structural or financial links between them," which represents "potential conflicts of interest." This situation compromises the independence necessary for the system's credibility.

Marginal but Revealing Frauds

Although cases of characterized fraud detected by the DGCCRF are "marginal," their existence reveals deeper dysfunctions. A 2024 study "evaluates at 1.7% the total share of 'abnormal' or even 'complacent' EPCs that could be suspected of being manipulated" - about 68,000 EPCs.

A Tool Unsuited to Its Renovation Mission

Paradoxically, the Court of Auditors questions "the usefulness of the EPC for planning renovation work, even though incentivizing energy renovation is part of the objectives assigned to this system." The energy renovation work proposals that may appear in the EPC "are generally written in a summary manner," contain "neither precise description of what is expected to improve the classification category, nor element on induced costs or on mobilizable public aid."

A Poorly Anticipated Reform

The Court of Auditors sharply criticizes the implementation of the 2021 reform: the implementation of the 2021 reform, which occurred within constrained deadlines, did not sufficiently anticipate the difficulties encountered by individuals to comply with it, while it has major consequences on their property situation and the real estate market.

Court of Auditors Recommendations

Faced with this alarming assessment, the Court of Auditors recommends several urgent measures:

Profession Structuring

Establishment of a "professional card" for diagnosticians by the end of 2026
Obligation of strict separation between training and certification missions
Establishment of "geographical incompatibility" for auditors who would have exercised another profession in the sector

Strengthening Controls

Implementation of in-depth statistical controls on diagnostic consistency
Use of artificial intelligence to detect suspicious values compared to building typology
Strengthening public information on possible appeals

Impact Assessment

Pierre Moscovici deplores that there is "no planned evaluation on the rental market and the real estate market" of the progressive ban on renting energy sieves.

A Considerable Financial Cost

The economic impact of the system is substantial. With the cost of an EPC ranging between 150-250 euros on average, we can estimate an annual cost of 800 million euros. This cost is accompanied by a lack of serious support for households facing work costing 30,000 to 70,000 euros.

Two Savoys Professionals Mobilized

In the Two Savoys, many certified real estate diagnosticians intervene to meet the growing demand: DOM EXPERT in Annecy and Chambéry, Diagnostic Thermique des Savoie which covers both departments, ACM Diags Immo in Annecy, or Diag Précision Savoie et Haute-Savoie in Chambéry.

These issues particularly affect altitude real estate professionals who daily observe the specific difficulties of the Alpine territory: old buildings in Annecy and Chambéry city centers, chalets and mountain residences with particular architectural constraints, seasonal housing in resorts like Chamonix, Courchevel, or Val d'Isère.

In Haute-Savoie, there are nearly 602 RGE qualified companies out of 16,709 building companies, only 4% of the sector, a concentration that reflects the challenges of energy renovation in mountain territory.

A Late Government Response

In reaction to criticism, Housing Minister Valérie Létard had presented in March 2025 a series of ten measures to credibilize the EPC, measures that "are generally in line with the findings and recommendations of the Court of Auditors."

Conclusion: A System to Rebuild, Territorial Stakes to Consider

The Court of Auditors report reveals the extent of dysfunctions in a system that has become central to French energy policy. Far from meeting the requirements set by the Climate and Resilience Law of 2021, the EPC still appears as a "defective compass," poorly calibrated, poorly controlled and with ambivalent effects on both owners and real estate professionals.

For Alpine territories like Savoie and Haute-Savoie, the stakes are all the more complex: old real estate stock in the historic centers of Annecy and Chambéry, specificities of mountain buildings, preponderance of electric heating penalized by the current EPC calculation, and major economic stakes for winter tourism.

The municipality of Les Arcs-Bourg-Saint-Maurice has taken the lead by launching a "Heritage and Energy" study to support owners in rehabilitating their housing, aware that "we have also chosen to create a mixed economy company (SEM) to build, rehabilitate and manage housing."

Faced with these damning findings, the question arises: how to restore confidence in a tool that now conditions access to the rental market and massively influences real estate investment decisions? The answer probably lies in a profound overhaul of the system, combining methodological rigor, reinforced professional training, systematic controls, and consideration of territorial specificities.

Without which, the EPC risks remaining what the Court of Auditors denounces: an imprecise instrument with disproportionate consequences, particularly penalizing for mountain territories.

Court of Auditors Report "Implementation of the Energy Performance Diagnosis", published June 3, 2025