Energy Performance Certificate (EPC): A poor rating could cost you up to 34,000 euros over ten years

Rent freezes, lower resale values, and rental bans: owning a home rated F or G is no longer just an energy-efficiency issue—it’s a measurable financial loss. While the 2026 Energy Performance Certificate (EPC) reform offers some owners a reprieve, inaction remains the most costly option. Here are the key figures you need to know.
 

Actual losses, city by city
The Energy Performance Certificate (DPE) is no longer just an administrative formality. Since the 2021 Climate & Resilience Act, it directly affects the right to rent, the ability to raise rents, and a property’s resale value. Properties classified as “G” have been banned from the rental market since January 2025; “F” properties will follow in 2028, and “E” properties in 2034. And the market didn’t wait for these deadlines to react: according to SeLoger, the share of energy-inefficient properties in rental listings fell from 14% to 8% between 2021 and 2025, while their share of properties for sale rose from 10% to 15%. Owners are trying to sell before the price discount worsens.
 

This discount has now been precisely quantified. A study by Maslow.immo, based on 2024 sales data, 2025 rental rates, and notary-certified discounts, compared the return on a well-rated 40-square-meter one-bedroom apartment with that of an identical property rated F or G over a ten-year period. In Levallois-Perret, the cumulative loss—lost rent and a discount upon resale—totals 34,032 euros. In Boulogne-Billancourt, it amounts to 32,674 euros, and in Suresnes, to 28,553 euros. In cities with more moderate prices, the ratio is even more severe relative to the capital invested: in Roubaix, a poor energy performance rating wipes out 16.6% of the property’s value.
 

The La Vigie barometer, which analyzes more than one million properties each quarter, confirms this divide. In the fourth quarter of 2025, the number of homes rated A-B increased (+1.27%), while the number of energy-inefficient F-G homes declined (-0.28%). For large apartments, the price gap between a G-rated and an A-B-rated energy performance certificate reaches 75% outside Paris. Only the most sought-after Parisian arrondissements still defy this trend, as location takes precedence over energy efficiency ratings there.
 

The 2026 Reform and the PTZ: Opportunities to Seize, but No Miracles
As of January 1, 2026, the electricity conversion factor used in calculating the Energy Performance Certificate (DPE) has been reduced from 2.3 to 1.9. As a direct result, approximately 850,000 electrically heated homes are no longer classified as energy-inefficient without any renovations. Seven million primary residences have improved by one energy efficiency class. Some 50,000 homes have moved from class G to F, earning a two-year reprieve before the rental ban takes effect. A free certificate can be downloaded from the ADEME website.
 

This is a real relief for the affected homeowners, who regain the right to rent out their properties and see their assets regain marketability. But the regulatory path has not changed: homes heated by gas or heating oil remain fully subject to the 2028 and 2034 deadlines. And the administrative reclassification does not alter either the home’s actual energy consumption or the amount of energy bills.
 

At the same time, the new PTZ program, which was expanded in April 2025, provides additional financial leverage. The maximum project costs have been raised by approximately 25%, and the program is now open to all new housing units nationwide, including single-family homes. Combined with MaPrimeRénov’ and the eco-PTZ, it makes it possible to finance major renovations with out-of-pocket costs that are sometimes lower than the cost of doing nothing.
 

For both homeowners and investors, the Energy Performance Certificate (EPC) has become a key decision-making factor in its own right, just like location, square footage, or price. Failing to incorporate it into one’s wealth management strategy means accepting a gradual erosion of the property’s value. Financial assistance is available, and the timeline is clear: all that’s left is to take action.