Taking a dwelling out of the thermal-sieve category — moving from F or G to D on the DPE (Diagnostic de Performance Énergétique, the French Energy Performance Certificate) — is not a cosmetic goal: it lifts the rental ban, restores part of the market value and unlocks loan access for a buyer. But the question "how much does it cost?" has no single answer. The works bundle required, its cost and the grade gain obtained depend on the property type: a 1970s detached house and a Haussmann-era flat both rated F do not renovate at the same price, nor with the same work items.
This article sets out works-bundle scenarios aimed at moving from F/G to D, by property type and construction era. For each profile, you will find the typical insulation + heating + ventilation combination, a cost range from ADEME data, the 2026 subsidies available (MaPrimeRénov' full-scale renovation and Energy Saving Certificates), and an indicative grade gain. All figures are sourced, illustrative orders of magnitude: the real result depends on the building, and only an audit or a simulation on your DPE confirms it.
About 5 million dwellings are rated F or G in France — roughly 15% of the residential stock according to the ministry's statistical service (SDES, stock as of 1 January 2024). All are affected by the rental-ban timetable: G since 2025, F in 2028. Reaching D leaves that timetable for good.
What this article covers
Why to aim for grade D rather than E (rental-ban timetable, green value, loan), how the 3CL methodology ranks the works needed to jump two grades, illustrative costed scenarios by property type (old house, recent house, flat in a co-ownership), the 2026 subsidies available for a full-scale renovation, and the pitfalls that lead to spending without reaching D. The amounts are ADEME ranges presented as an indication.
Why aim for D when you start from F or G
The DPE rates dwellings from A (the most efficient) to G (the most energy-intensive) using two primary-energy indicators: consumption (in kWh/m²/year) and greenhouse gas emissions. Its validity period is ten years (French Construction and Housing Code — CCH — article D.126-19). Since the reform of 1 July 2021, it is binding: the displayed grade triggers direct regulatory consequences.
The first is the rental-ban timetable for thermal sieves, set out in Act no. 2021-1104 of 22 August 2021 (the Climate & Resilience Act) in articles L.173-1-1 and L.173-2 of the CCH. G-rated dwellings have been banned from rental since 1 January 2025, F-rated ones will be from 1 January 2028, and E-rated ones from 1 January 2034.
This timetable explains why aiming for D rather than E changes everything. Reaching only E takes a property out of the 2025 and 2028 bans, but places it back under the 2034 deadline: the renovation will have to be redone. Reaching D shelters the dwelling from the timetable known to date. For a landlord, that is the difference between a project that secures the rental for a decade and a project to be redone.
| Deadline | Grade banned from rental | Legal reference |
|---|---|---|
| 1 January 2025 | G | CCH art. L.173-1-1 (Act no. 2021-1104) |
| 1 January 2028 | F | CCH art. L.173-1-1 |
| 1 January 2034 | E | CCH art. L.173-1-1 |
The second reason is about asset value. Studies by Notaires de France (the French Notaries Federation) have for several years measured a sale discount on F- and G-rated dwellings compared with D-rated ones, varying by region and property type. Reaching D restores part of this green value and eases the buyer's loan, as banks now factor the DPE grade into their risk analysis. The extent of the discount by location is detailed in our DPE discount simulator.
How the 3CL methodology forces a bundle to jump two grades
The DPE grade is calculated by the 3CL-DPE methodology, defined by the ministerial order of 31 March 2021 (amended by the ministerial order of 25 March 2024). It reconstructs the dwelling's heat losses item by item — roof, walls, windows, floors, thermal bridges, air renewal — then weights them by the heating system and its efficiency. Understanding this logic explains why a two-grade jump (F/G to D) almost always requires several combined works.
Why a single action rarely reaches D
An F- or G-rated dwelling generally combines several weaknesses: a poorly insulated envelope and an energy-intensive heating system. Tackling a single item — for example insulating the lofts — can gain one grade, but rarely two: the other items remain weak links that cap the gain. To jump two grades, you must address both the envelope (roof, walls) and, most often, the system. This is the logic of the works bundle.
Profile: an F-rated dwelling heated by oil or gas combines a double handicap — high consumption and greenhouse gas emissions that can cap its grade. For this profile, replacing the heating system is often essential to reach D, on top of insulation.
The order of works: the envelope first, the system second
Insulating before changing the heating allows the new equipment to be correctly sized: a heat pump (PAC — pompe à chaleur) installed in a still poorly insulated dwelling will be oversized, more expensive and less efficient. This is the rule advocated by ADEME and France Rénov' (the public home renovation advice service): the envelope first, the system second. The detail of this sequence — and the trade-off between external and internal insulation — is covered in our comparison external vs internal insulation: how to choose.
The effect of the 2026 electricity coefficient on the size of the bundle
The 3CL methodology converts final energy into primary energy via a coefficient. For electricity, this coefficient has dropped from 2.3 to 1.9 (ministerial order of 13 August 2025, published in the Official Journal on 26 August 2025, in force on 1 January 2026). For a dwelling already heated by electricity, this fall mechanically reduces the displayed primary-energy consumption — and can lighten the bundle needed to reach D. Before costing a project, it is therefore essential to start from the rating recalculated with the 2026 coefficients.
Costed scenarios by property type to move from F/G to D
Here are three representative profiles, each with a typical bundle and a cost range built from ADEME data. The amounts are illustrative and presented as an indication, excluding subsidies: they show the trade-off logic by property type, not a guaranteed result. The grade gain is indicative and depends on the building, the climate and the initial condition.
Scenario 1 — Old house (before 1975), rated F or G
Scenario A — 100 m² detached house, uninsulated walls, empty lofts, oil heating
This is the profile where the bundle is heaviest, because everything needs doing: the envelope and the system. Conversely, it is also the one where each item produces strong leverage, since the starting point is very low. The F/G → D goal is generally reachable with an envelope + heating bundle.
| Work item | Logic | Indicative cost (excl. subsidies) |
|---|---|---|
| Empty loft insulation | Weak link no. 1, best ROI — ~€25 to €75 / m² (ADEME) | ~€2,000 to €5,000 |
| Wall insulation (external or internal) | Weak link no. 2, big lever — fundable in full-scale renovation | ~€12,000 to €30,000 |
| Air-to-water heat pump (replaces oil) | Lifts the oil GHG cap, sized after insulation | ~€10,000 to €16,000 |
| Humidity-controlled VMC | Secures air quality after insulation | ~€1,000 to €3,000 |
| Indicative bundle total | — | ~€25,000 to €54,000 |
| Out-of-pocket cost after subsidies | Full-scale MPR + CEE + eco-PTZ + 5.5% VAT | Significantly reduced, to be costed |
For this profile, a two-grade gain (F/G → D) is the typical goal of a full-scale renovation. Insulation alone often gains one grade; it is the addition of the heating change that unlocks the second, especially when oil caps the rating through its emissions.
Scenario 2 — Recent house (1975-2000), rated F because of its heating
Scenario B — 110 m² house partially insulated, electric heating with old convectors
A house built after the first thermal regulations may be rated F not because of its envelope, but because of worn-out electric heating and partial insulation. The bundle is then lighter: you complete the existing insulation and replace the heating. The effect of the 2026 electricity coefficient plays fully here, since the dwelling is already heated by electricity.
| Work item | Logic | Indicative cost (excl. subsidies) |
|---|---|---|
| Loft insulation top-up | Completes the existing layer, moderate cost | ~€1,500 to €4,000 |
| Air-to-water or air-to-air heat pump | Replaces the convectors, cuts heating consumption | ~€8,000 to €15,000 |
| Windows (priority items) | Double glazing where single glazing remains | ~€3,000 to €8,000 |
| Humidity-controlled VMC | Improves the air renewal accounted for by the 3CL method | ~€1,000 to €3,000 |
| Indicative bundle total | — | ~€13,500 to €30,000 |
| Out-of-pocket cost after subsidies | MPR (single action or full-scale) + CEE + 5.5% VAT | Reduced, to be costed |
Depending on the case, this profile can reach D without wall insulation, and therefore without necessarily shifting into full-scale renovation if the heat pump and loft insulation are enough to jump two grades. The audit decides.
Scenario 3 — Flat in a co-ownership, rated F or G
Scenario C — 60 m² flat in an old building, individual heating, walls on the exterior
The flat is the most constrained case, because some of the levers do not depend on the owner alone. Roof insulation and external wall insulation are co-ownership decisions, voted at the general meeting. At the scale of the lot, the owner mainly controls internal wall insulation, the windows and the individual heating system.
| Work item | Logic | Indicative cost (excl. subsidies) |
|---|---|---|
| Internal wall insulation | Lever controllable alone, but loss of living space | ~€5,000 to €12,000 |
| Windows (double/triple glazing) | Several hundred € / window (ADEME) | ~€3,000 to €8,000 |
| Efficient individual heating system | Heat pump, or heat-network connection if available | ~€5,000 to €14,000 |
| VMC (depending on configuration) | Air renewal, subject to feasibility | ~€800 to €2,500 |
| Indicative bundle total (lot only) | — | ~€13,800 to €36,500 |
| Out-of-pocket cost after subsidies | MPR (dwelling) + CEE + MPR Copropriété for common areas | Reduced, to be costed |
⚠️ Warning: in a flat, reaching D at the scale of the lot alone is not always possible if the building is poorly insulated in its common areas (roof, façades). The two-grade jump often goes through a renovation of the common areas, funded via MaPrimeRénov' Copropriété and voted at the general meeting. Have an audit done before committing to works inside your lot only.
The 2026 subsidies for an F/G to D renovation
The two-grade jump falls, in most cases, under the MaPrimeRénov' full-scale renovation route, the most heavily subsidised. Here are the levers available in 2026, per the schedules published by ANAH (the French National Housing Agency).
MaPrimeRénov' full-scale renovation
The supervised route (full-scale renovation) funds bundles aimed at a gain of at least two grades. It requires an energy audit, the use of a Mon Accompagnateur Rénov' supervisor and RGE-certified companies (Reconnu Garant de l'Environnement). It is within this framework that wall insulation (both internal and external), excluded from the single-action route since 1 January 2026, becomes fundable again. The subsidy rate depends on the targeted grade gain and the household's income category. The MaPrimeRénov' desk reopened on 23 February 2026, with a France Rénov' appointment required beforehand.
CEE, eco-PTZ and reduced VAT
Energy Saving Certificates (CEE — Certificats d'Économies d'Énergie, bonuses funded by energy suppliers) combine with MaPrimeRénov' on the single-action route. On the supported route, however, the Anah is the sole claimant of the certificates and applies them towards the grant: they do not add to it. And for any operation committed from 1 September 2026 — through the Anah, the previous rules still apply if the application was filed before that date, even if the works are committed later (Article 8(III)) —, the whole-home CEE bonus is restricted to homes rated E, F or G before works and requires, in a single-family house, that no fossil-fuel equipment remains afterwards: an F/G to D scenario that keeps the gas boiler stays fundable through MaPrimeRénov' but loses that bonus (ministerial order of 17 August 2026). The eco-PTZ (the zero-rate renovation loan up to €50,000) funds the out-of-pocket cost interest-free, and the reduced 5.5% VAT (CGI art. 278-0 bis A) applies to energy-performance improvement works. Combining these levers significantly reduces the out-of-pocket cost, but the latter remains to be costed case by case depending on the quotes and the income category.
⚠️ Warning: since 1 January 2026, wall insulation (both internal and external) has been excluded from the MaPrimeRénov' single-action route (ministerial order of 12 June 2026, amending the order of 17 November 2020). For an F/G → D jump that includes wall insulation, only the full-scale renovation route grants the subsidy. A quote offering external insulation "funded by MaPrimeRénov'" as a single action is based on outdated rules.
The pitfalls that lead to spending without reaching D
Mistake no. 1 — Aiming for E instead of D to save money
Stopping at E costs less in the short term, but places the dwelling back under the 2034 ban deadline. The renovation will then have to be redone, with a total cost often higher than that of a bundle aimed at D from the start. When the budget allows, aiming straight for D avoids a second project.
Mistake no. 2 — Changing the heating before insulating
Installing a heat pump in a still poorly insulated dwelling leads to oversizing it: the equipment costs more, runs less efficiently, and the grade gain is lower than it would have been after insulation. The envelope first, the system second: this is the basic rule advocated by ADEME and France Rénov'.
Mistake no. 3 — Underestimating the dependence on the co-ownership in a flat
In a flat, committing to works inside your lot alone without considering the state of the common areas may not be enough to reach D. Roof and façade insulation are co-ownership matters: it is often necessary to coordinate private works with a common-area renovation voted at the general meeting.
⚠️ Warning: no professional can guarantee reaching D before studying the building. Be wary of quotes promising "D guaranteed" before any audit: the gain depends on the dwelling, the climate and the initial condition. The only certainty comes from a simulation on your real DPE or an energy audit.
Mistake no. 4 — Starting works before checking the 2026 rating
Since 1 January 2026, the electricity coefficient of the 3CL methodology has dropped from 2.3 to 1.9. An electrically heated dwelling may have moved closer to D with no works at all. Starting from an outdated rating can lead to oversizing the bundle. Always check the rating recalculated with the 2026 coefficients before costing.
Simulate your move from F/G to D before signing
OneDpe works and DPE grade-gain simulator
Build your bundle item by item — loft insulation, wall insulation, windows, heat pump, ventilation — and see the estimated new rating, the expected grade gain and the cost, with the 2026 subsidies built in (MaPrimeRénov', CEE, eco-PTZ). You immediately see which bundle reaches D for your property type, and what out-of-pocket cost to expect after subsidies.
Going further: the DPE discount simulator and the guide gain one EPC grade: the 5 works with the best ROI.
Conclusion
Moving from F or G to D has no single cost: it depends on the property type. An old house requires a full envelope + heating bundle, the heaviest but the most effective; a recent house rated F because of its heating often gets there with a lighter bundle; a flat depends largely on the co-ownership's decisions to genuinely jump two grades. In every case, the order — envelope first, system second — and the use of the MaPrimeRénov' full-scale renovation route condition the result as much as the choice of items.
Before the first quote, the OneDpe works and DPE grade-gain simulator lets you test each bundle by property type, check whether it reaches D, and weigh the indicative cost against the real out-of-pocket cost after subsidies.
