Are you selling (or buying) a home whose energy performance certificate (DPE — the French equivalent of the EPC, Energy Performance Certificate) shows an F or a G? That single letter can move the price by tens of thousands of euros. In 2024, an older house rated G sold for an average of 25% less than a comparable house rated D, and a G-rated flat sold for 12% less (Notaires de France — the French notaries — green value of 2024 transactions). Professionals call this the "green value": the share of the price attributable to energy performance.
Yet almost every online valuation tool ignores the EPC rating in its calculation. You get an average price per square metre, with no idea how much your energy class actually costs you — or earns you. This article puts a euro figure on green value, places the EPC within the Climate Law timetable (which weighs on your property's future value), and shows how to estimate it for your own home.
1.9 times — that is the price ratio between an older 90-to-110 m² house rated A or B and the same house rated F or G, measured on 2024 sales, versus only 1.5 times in 2021 (Notaires de France, 2024 transactions).
What this article covers
You will find here a definition of green value, the official discount and premium figures per EPC class from the French notaries' 2024 study, the regulatory framework (Climate Law, the rental ban timetable, the EPC calculation reform of 1 January 2026), a full worked example on a G-rated house, the common mistakes to avoid before selling or buying, and the method to estimate the EPC's impact on your own home.
EPC, green value and the Climate Law: the regulatory framework
Green value is not a passing trend: it has been amplified by a legal framework that turns the energy rating into an economic variable. Three sets of rules shape it — the rating itself, the rental ban timetable, and the reform of the EPC calculation method.
The A-to-G energy rating
The EPC rates every dwelling from A (very efficient) to G (very energy-intensive), based on its primary energy consumption and its greenhouse gas emissions. This rating is set out in Article L.173-1-1 of the Construction and Housing Code (CCH), created by Article 148 of the Climate and Resilience Law (Law No. 2021-1104 of 22 August 2021). Homes rated F or G are called "thermal sieves" (passoires thermiques). The EPC determines the rating; on its own, it does not set the ban timetable.
The timetable for banning rentals of thermal sieves
It is the housing decency standard, not the EPC itself, that progressively bans the renting of thermal sieves. The minimum energy-performance threshold was introduced by Article 6 of Law No. 89-462 of 6 July 1989 and specified by Decree No. 2023-796 of 18 August 2023. In mainland France the timetable is as follows:
| EPC class | Renting banned from | Reference |
|---|---|---|
| G | 1 January 2025 | Art. 6 Law 89-462 / Decree 2023-796 |
| F | 1 January 2028 | Art. 6 Law 89-462 / Decree 2023-796 |
| E | 1 January 2034 | Art. 6 Law 89-462 / Decree 2023-796 |
Two related obligations come on top: a rent freeze on F and G homes since 24 August 2022 (Decree No. 2022-1079), which bars any rent increase until the thermal sieve is renovated, and a mandatory energy audit when selling F and G homes since 1 April 2023 (extended to E homes on 1 January 2025, and planned for D homes on 1 January 2034; Article L.126-28-1 of the CCH). If you rent out, or plan to, these deadlines hit your income directly: it can help to anticipate their effect with the rental yield simulator.
⚠️ Warning: as of today this timetable is in force. A "Housing Recovery" bill presented to the Council of Ministers on 24 June 2026 could allow F or G homes to be re-let subject to a renovation commitment; it has not been adopted. The ban on renting a G-rated home (in force since 1 January 2025) still applies. The 2028 and 2034 deadlines should therefore be read subject to legislative change.
The EPC reform of 1 January 2026
On 1 January 2026, the primary-energy conversion coefficient for electricity drops from 2.3 to 1.9 in the EPC calculation method. In practice, some electrically heated homes gain a class — sometimes two for small units — without any works. A better rating mechanically reduces the green-value discount applied to the property: a home moving from F to E leaves the category of thermal sieves and escapes (as the law currently stands) the 2028 rental ban.
The stakes are large: classes E, F and G alone accounted for 40% of older-home transactions in 2024, and F-G thermal sieves for roughly 15% of sales (Notaires de France). Energy performance is therefore not a marginal criterion for a few homes: it concerns almost one sale in two.
How much the EPC adds or subtracts: the green-value figures
Green value is defined as the difference in sale price attributable to a home's energy performance, all else being equal (same area, same type, same surface). The French notaries measure it every year on real transactions recorded in their notarial databases PERVAL (province) and BIEN (Greater Paris), taking class D as the reference. Here are the average gaps from the 2024 transactions.
| EPC class | House (gap vs D) | Flat (gap vs D) |
|---|---|---|
| A | +17% | +16% |
| B | not detailed | +12% |
| C | not detailed | +6% |
| D | reference | reference |
| G | −25% | −12% |
Source: Notaires de France, green value of 2024 transactions. Average gaps, all else being equal (PERVAL and BIEN databases). No discount figure for classes E or F is shown here, as no value is confirmed in the primary source for this vintage, and the B and C premiums for houses are not detailed by the study.
These national averages hide wide local differences. A thermal sieve's discount is steeper where the market is slack: in high-demand areas, the buyer has less room to negotiate. The 2024 study thus measures a price ratio between A-B and F-G classes of about 2.1 times in Lille, but only 1.2 times in Lyon and Bordeaux. A national percentage is never enough: only an address-level estimate, anchored to the local market, makes sense.
How our estimate quantifies the EPC's impact
Our estimate applies a discount coefficient calibrated on the French notaries' study, re-centred on the median EPC class of your area — so as not to count twice a discount already priced into the local market — applied to a median price drawn from the public French Buildings Database (BDNB), at the level of the municipality and the IRIS neighbourhood. A comparison layer based on DVF transactions (Land Value Requests, French tax authority / Etalab) is being rolled out; it will cover France excluding Alsace-Moselle (Bas-Rhin, Haut-Rhin, Moselle) and Mayotte, with the non-re-identification and non-indexing safeguards required by Article R.112 A-3 of the Book of Tax Procedures. This is an indicative estimate, not a valuation report.
Your property's future value
Green value is not read in the present alone. A home rated F and discounted today will face extra pressure as the 2028 rental ban approaches: a landlord who can no longer rent will be keener to sell, and the buyer will factor the cost of works into the negotiation. Conversely, a re-rating — through energy-renovation works or through the 2026 calculation reform — can recover part of the discount. Estimating an energy-intensive home therefore means estimating two values: today's, and the anticipated value of the renovated or re-rated home.
Worked example: a G-rated house at €2,200/m²
Take an indicative case based on a realistic market order of magnitude: an older 100 m² house in an area where the reference price is around €2,200/m² (an order of magnitude for house prices drawn from DVF data). Applying this "all classes combined" price, the house would be worth about €220,000. But its EPC shows a G, whereas the neighbourhood's median class is a D: the thermal-sieve discount must therefore be applied.
Scenario — 100 m² house, local median class D, actual rating G
| Scenario | Price per m² | Area | Indicative estimate |
|---|---|---|---|
| Reference (neighbourhood class D) | €2,200/m² | 100 m² | ~€220,000 |
| Same house rated G (−25%) | ~€1,650/m² | 100 m² | ~€165,000 |
That is an indicative loss of about €55,000 attributable to the G rating — according to our estimates, using the discount coefficient calibrated on the French notaries' study (2024 transactions) applied to an area median price. For a buyer, this is the theoretical negotiating margin facing a thermal-sieve seller; for a seller, it is the order of magnitude that renovation works could recover. When buying, also factor in acquisition costs with the notary fees calculator.
Key takeaway: these amounts are orders of magnitude. The real discount depends on the tightness of your local market (from 1.2 to 2.1 times between extremes depending on the city) and on the median EPC class of your neighbourhood. Run the free indicative estimate for your address to get a range tailored to your property.
Green value: 5 traps to avoid before selling or buying
Trap 1 — Applying a national percentage to your street
The −25% discount on a G-rated house is a national average. On the ground, the gap varies twofold: an energy-intensive home loses a lot of value in a slack city, but relatively little in a tight market where demand absorbs everything. Relying on a national figure for a property in Lille and one in Lyon produces two equally wrong estimates.
Trap 2 — Confusing the discount vs D with the A-B/F-G ratio
Two figures often travel together yet measure different things. The −25% discount compares a G-rated house with a D-rated one. The 1.9-times ratio compares the two market extremes (A-B versus F-G). Confusing them leads to greatly over- or under-estimating the rating's effect on a mid-class property.
Trap 3 — Forgetting the future value
A thermal sieve that sells well today is not safe. A home rated F will be hit by the 2028 rental ban (subject to the 2026 Housing Recovery bill), which will depress its price as the deadline nears. Buying a thermal sieve without budgeting for renovation, or selling one without anticipating this regulatory wall, exposes you to a nasty surprise.
Trap 4 — Relying on an outdated estimate
The property market has turned upward again: the French notaries count about 958,000 sales over one year at the end of February 2026, up 11%, and prices have stabilised (+1.1% year-on-year in the fourth quarter of 2025). An estimate from a year ago, made at the bottom of the market, can be markedly off. Always refresh your value before a decision.
Trap 5 — Confusing an estimate with a valuation report
An online simulator provides an indicative estimate, useful to prepare a sale, a purchase or a negotiation. It is not an appraisal or a binding valuation: only a professional holding the "Transactions" licence (Hoguet Law, Law No. 70-9 of 2 January 1970) may issue those reserved acts. For a loan file, an inheritance or a dispute, have the value confirmed by a professional.
Key takeaway: in the fourth quarter of 2024, roughly one in four sales of flats under 40 m² involved a home rated F or G. The EPC reforms for small units (2024) and then for the electricity coefficient (2026) re-rate part of this stock — something to check before buying or selling an energy-intensive studio.
Estimate the EPC's impact on your property
Our simulator computes a value range from the price per square metre of your neighbourhood and puts a euro figure on the impact of your EPC rating relative to the local median class — with no account and no email. It is an indicative estimate to prepare a sale, a purchase or a negotiation, not a binding valuation.
To go further: calculate the capital gain on your sale.
In short
The EPC has become a major price driver: a G-rated house sells for about 25% less than a comparable D-rated house, a G-rated flat 12% less, and the gap varies widely with the local market. With the Climate Law timetable and the 2026 calculation reform, the energy rating will weigh even more heavily on home values in the years ahead.
Before setting a sale price or a purchase offer, quantify this effect precisely for your property. The free indicative property estimate from Mon Simulateur Immobilier combines your neighbourhood's price per square metre with your EPC class to translate green value into euros, with no canvassing and no capture of your contact details.
