France lowered the electricity conversion factor used in its energy performance diagnosis from 2.3 to 1.9 on 1 January 2026. A ski apartment can therefore receive a better energy rating without a window being replaced. That is a useful distinction to carry into an autumn viewing: the paperwork may have improved while the draught by the balcony door remains thoroughly familiar. The change is recorded in Service Public’s DPE guidance.
For a buyer living abroad, the diagnostic de performance énergétique, or DPE, is an accessible starting point for comparing French homes. It becomes much more useful when read alongside the heating system, the building’s condition and evidence of actual occupation. This is a September 2026 reading of the rules and a practical way to turn the coloured letter on a listing into questions worth asking before an offer.
A better letter needs an explanation
First establish why the advertised rating has changed. Has the owner insulated the apartment, replaced equipment or obtained an updated label under the revised calculation? Ask for the original report and any official attestation together. A screenshot of a solitary letter leaves too much of the story outside the frame.
There is another date to keep separate. In an announcement published on 31 August 2026, the ecological transition ministry confirmed a further reduction to 1.7 from 1 January 2027. It says existing diagnoses will remain valid and an online update will be available without another inspection. That future factor is not the one applying to a new DPE in September 2026.
For an autumn purchase, keep the current documented rating and any future projection in separate columns. If an agent says the flat “will be a D”, request the basis and timing. A possible later improvement should not substitute for the report available today, nor should it be presented as completed renovation. The useful question is what has changed physically, what has changed mathematically, and what still needs money.
Understand the electricity arithmetic
The distinction is between final energy, delivered to the home, and primary energy, which accounts for energy before conversion and delivery. The ministry’s explanation of the calculation also confirms that the overall DPE class takes the worse result from the energy and greenhouse-gas assessments. A lower electricity factor therefore does not guarantee a particular new letter.
Consider an explicitly hypothetical, entirely electric dwelling whose modelled final consumption is 100 kWh per square metre per year. Multiplying by 2.3 gives 230; multiplying by 1.9 gives 190. That is a 17.4% reduction in the calculated primary-energy figure, obtained by dividing the difference of 40 by the original 230. The example describes accounting, not a measured fall in the electricity used by an Alpine apartment.
This matters during negotiations. Ask a seller claiming lower running costs for the evidence behind that separate claim. The same radiators, glazing and temperature settings have not acquired new physical properties because a multiplier changed. Conversely, dismissing an electrically heated flat solely on an old label may mean comparing it with another property on an inconsistent basis. Obtain comparable documents before deciding which address deserves a second visit.
Check the report behind the advertisement
Start with the apartment’s identity, report date and supporting documents. Service Public states that diagnoses made since July 2021 normally last 10 years; those issued from January 2018 to June 2021 ceased to be valid in January 2025. It also records the adjusted thresholds introduced in July 2024 for homes with a reference area of 40 m² or less. A compact studio warrants a check that the relevant attestation accompanies an older report. These details are in its current DPE guidance.
Match the address, floor and dwelling description to the apartment you saw. Read the equipment and insulation entries before the recommendations. If the report describes a different water heater, or the seller says insulation was installed after the inspection, ask for the evidence and an explanation from the diagnostician. A date discrepancy is a question to resolve, rather than an invitation to choose whichever document has the friendliest colour.
The ministry’s DPE overview explains that the ADEME identification number allows a diagnosis to be checked. Save the report and attestations together in your purchase file. Forwarding them to your adviser is more productive than translating a rating from memory during a hurried telephone call.
Build a holiday budget from occupied weeks
A DPE is a standardised assessment, not a receipt for your next winter. The official energy statistics service describes its scope as five energy uses: heating, domestic hot water, cooling, lighting and auxiliaries. Its energy efficiency definitions make that conventional basis explicit. Your actual household bill and the assessment cover different questions.
Request recent bills, then ask how the apartment was used during the same periods. Was it empty for much of winter? Were guests there continuously? Was heating included in shared charges? An impressively small electricity bill is much less revealing if the principal heating cost appears elsewhere, or if the owner only visited in July.
For your own budget, write down intended winter stays, likely guest use, changeover arrangements and periods without occupants. Ask the managing agent how the property is monitored when empty and what settings the equipment supplier recommends. Include subscriptions and the relevant shared charges rather than estimating everything by multiplying the seller’s average monthly payment.
For a remote viewing, request photographs of heating controls, the hot-water installation and the relevant pages of the charge statement. Ask someone on site to demonstrate the controls on video. A system that is easy to operate and explain to guests may be more useful to you than an impressive specification nobody can find instructions for.
Read the building’s diagnosis as well
The apartment is only part of the purchase. According to Service Public’s collective DPE guidance, residential collective buildings with a permit application predating 1 January 2013 must have a building-level diagnosis, with the timetable reaching the smallest qualifying co-ownerships in 2026. The collective assessment is distinct from the individual apartment’s report and from an energy audit.
Ask the syndic, through the seller, for the collective diagnosis and the discussion of its recommendations. Then connect the energy findings to the practical work under consideration. If a report points towards roof insulation, establish whether anything has been surveyed, priced, voted or scheduled. A recommendation and a funded project are very different entries in a buying budget.
Keep the conversation specific to this building. A comfortable middle-floor apartment and an exposed top-floor flat can present different concerns even when they share an address. Ask the professional reviewing the reports to explain the differences rather than assuming the collective letter describes every room equally well.
For a non-resident owner, organisation belongs in the assessment too. Who would supervise work inside the flat, arrange access and check completion while you are abroad? Obtain an answer before placing a confident renovation allowance in the spreadsheet.
Compare resale evidence with new-build promises
Resale offers the chance to inspect an occupied property and request operating records. Off-plan buying involves specifications and a home still to be delivered. Service Public says the new-home DPE must be handed to the buyer by delivery at the latest. A projected label in a sales presentation and a delivered dwelling’s diagnosis should therefore be identified clearly when comparing offers.
Use the same questions across both: what supplies the heating, how is hot water produced, what can the owner control, and which costs sit with the building? For a new development, ask where those answers appear in the contractual specification. For a resale, ask whether the equipment described remains installed and whether servicing records are available.
The DOMOSNO new-build selection can help establish a shortlist, but a listing is the beginning of that enquiry. Do not infer a particular DPE, heating bill or saving from the word “new”. Likewise, an older apartment’s refurbishment needs should be supported by inspection and quotations. Neither age nor a polished kitchen supplies a dependable energy budget.
Turn the rating into purchase decisions
Before offering, assemble a short comparison for each serious candidate: current individual DPE, any official replacement label, actual energy records with occupation explained, relevant building documents, and questions requiring a professional answer. Record the date beside every item. This helps keep a September certificate separate from a seller’s prediction about January.
Use the findings to decide what the next step should be. An equipment mismatch calls for clarification. Suspected defects call for inspection. Proposed works call for a defined scope and quotations. An unexplained jump in the energy letter calls for the attestation. Each issue has a more useful response than applying a generic percentage discount to the asking price.
If rental income is essential to the purchase, have the intended letting arrangement and the property’s applicable energy requirements checked before relying on an income projection. A label alone cannot settle every condition attached to a proposed use. Keep that review tied to the actual address and ownership plans.
The aim is to understand the home you will own: how it performs, what needs attention, and what you can realistically manage from abroad. Keep the better rating where it belongs, as one documented part of that decision. The balcony view can still win you over; it simply need not do the arithmetic.
If you are comparing Alpine apartments this autumn, contact DOMOSNO with your shortlist and intended use, and we can help gather the property information that makes a second viewing worthwhile.
