A chalet or a mountain house does not read like a valley-floor apartment on an energy performance certificate. Altitude, wood-burning heating, walls built of squared logs or stone, roofs exposed to months of cold — all of it pushes the rating, sometimes up and sometimes down. Before you put a property on the market in the Arve or Mont-Blanc valley, it is worth understanding how the diagnostic de performance energetique (DPE — France's compulsory energy performance certificate) is calculated at altitude, what it means for the sale, and where the unpleasant surprises come from. This guide sets out the rules as they stand in 2026.
The DPE is compulsory to sell: the rules in 2026
Validity. A DPE is valid for ten years. Be careful with older ones: certificates issued between 1 January 2018 and 30 June 2021 stopped being valid on 1 January 2025. If your chalet was surveyed in that window, you need a new certificate before you can sell.
What goes in the listing. The energy and climate labels, together with the estimated annual running cost, must appear in the advertisement from the moment the property goes on the market. A property rated F or G must also carry the wording logement a consommation energetique excessive (« excessive energy consumption »).
It can be challenged. Since the July 2021 reform the DPE is opposable — legally binding. A buyer who believes they were misled by an inaccurate certificate can pursue the surveyor. That is the real argument for a certificate that reflects the property honestly, neither flattering nor pessimistic.
The energy audit. To sell a detached house (or a whole building in single ownership) rated E, F or G, an audit energetique must be handed to the buyer alongside the DPE. Apartments in a co-ownership are not affected. From 2034 the requirement extends to houses rated D.
A certificate issued before 2026 is worth refreshing
Since 1 January 2026 the conversion factor applied to electricity in the DPE calculation has dropped from 2.3 to 1.9. For a chalet heated electrically, the rating can therefore improve on its own, with no work done to the building. Certificates issued before 2026 remain valid and can be refreshed free of charge through ADEME's DPE observatory, with no second visit from the surveyor. No property's rating is downgraded by the change (French Ministry for the Ecological Transition).
If you are preparing to sell an electrically heated chalet, this is the first thing to check. A rating that moves from F to E removes the energy-audit requirement and takes the « excessive consumption » wording out of your listing — for the cost of a form.
What altitude changes: easier thresholds above 800 m
The official calculation method (methode 3CL) takes local climate into account. A chalet at 1,100 m needs more heating than an identical house on the valley floor, and that is not the owner's fault. To avoid penalising these properties, the regulations set relaxed thresholds for classes E, F and G where the property sits in climate zone H1b, H1c or H2d and above 800 m of altitude. Haute-Savoie is classified H1c, so these thresholds apply to every property in the department above 800 m.
In our own patch, Megève, Chamonix, Les Houches, Combloux and the Plateau d'Assy sit above that line, while Sallanches and the valley floor stay below it. Saint-Gervais-les-Bains straddles it, from Le Fayet on the valley floor up to the high hamlets. What counts is the altitude of the property itself — confirm it with the surveyor rather than assuming from the commune name.
| Class | Standard thresholds | Above 800 m (zones H1b, H1c, H2d) |
|---|---|---|
| A | ≤ 70 kWh / ≤ 6 kg CO₂ | Same |
| B | ≤ 110 kWh / ≤ 11 kg CO₂ | Same |
| C | ≤ 180 kWh / ≤ 30 kg CO₂ | Same |
| D | ≤ 250 kWh / ≤ 50 kg CO₂ | Same |
| E | ≤ 330 kWh / ≤ 70 kg CO₂ | ≤ 390 kWh / ≤ 80 kg CO₂ |
| F | ≤ 420 kWh / ≤ 100 kg CO₂ | ≤ 500 kWh / ≤ 110 kg CO₂ |
| G | > 420 kWh / > 100 kg CO₂ | > 500 kWh / > 110 kg CO₂ |
Primary energy consumption in kWh/m²/year and greenhouse gas emissions in kg CO₂eq/m²/year. The final label is whichever of the two is worse. Thresholds set by the arrete of 31 March 2021 on the energy performance certificate. Separate thresholds also apply to homes of 40 m² or less, since 1 July 2024 (service-public.gouv.fr).
The practical consequence for a seller: a chalet above 800 m rated F on the standard scale may well be an E once the altitude thresholds are applied — and an E does not carry the « excessive consumption » wording. It is worth asking the surveyor to confirm which scale was used.
What weighs on a mountain property's rating
Two things surprise owners most often.
Wood heating helps less than people expect. A wood burner or a log boiler scores very well on the climate label, because the emissions factor for wood is low. But the energy label depends on consumption, and an old insert burning through the winter in a poorly insulated chalet still consumes a great deal. A chalet can therefore come out with a good climate rating and a mediocre energy one — and the label you are given is the worse of the two.
Traditional construction is not insulation. Squared-log walls and thick stone have real thermal mass, which is why an old chalet feels comfortable in summer. The method credits insulation, not inertia. Roofs and lofts are usually where the loss is, followed by single or early double glazing and the heating system itself.
Before you put a chalet on the market
- Find the existing certificate and check its date. Anything surveyed between January 2018 and June 2021 is void.
- If the chalet is electrically heated, refresh the certificate through the ADEME observatory before anything else. Free, and it may move the label.
- Confirm the altitude of the property, not of the commune, and ask which threshold scale was applied.
- Gather the invoices for insulation, glazing, the boiler or the burner. A surveyor who can see what was done rates what is actually there rather than assuming the worst.
- If the result is E, F or G, budget for the energy audit: it has to be in the buyer's hands, and it takes time to produce.
Selling a chalet rated F or G
It is perfectly legal. The letting rules are what tighten year by year, not the right to sell. What changes is the negotiation: a buyer who reads F on the listing arrives with the audit's estimated works in mind, and prices accordingly.
In this valley that matters less than it would elsewhere, for one specific reason. A large share of buyers here are buying a second home, and many intend to renovate to their own taste anyway. A fair price and a clear, documented picture of the building usually sells better than an optimistic certificate that a buyer's own surveyor then unpicks.
If the chalet is let
The rules for letting are stricter than for selling and they move on a published timetable. If the property is currently let, or you intend to let it rather than sell, the DPE class decides whether you may continue. Ask us before you commit either way — in the Chamonix valley the letting permit and the DPE interact, and the order you do things in matters.
Frequently asked questions
Is a DPE compulsory to sell a chalet?
Yes. It must exist before the property is advertised, and the energy and climate labels must appear in the listing itself. Without it the sale cannot proceed to completion, and the buyer may challenge the price afterwards.
Does altitude change the rating?
Yes, for classes E, F and G. Above 800 m in climate zone H1b, H1c or H2d — which covers all of Haute-Savoie above that altitude — relaxed thresholds apply. Classes A to D are unchanged. It is the altitude of the property that counts, not of the commune.
Does a wood burner improve the rating?
It improves the climate label, because wood has a low emissions factor. It does not necessarily improve the energy label, which measures consumption. The final rating is the worse of the two, so a wood-heated chalet with thin insulation often lands lower than its owner expects.
My certificate is from 2019 — is it still valid?
No. Certificates issued between 1 January 2018 and 30 June 2021 ceased to be valid on 1 January 2025. You need a new one before selling.
Do I need an energy audit to sell a chalet?
If it is a detached house rated E, F or G, yes — the audit energetique goes to the buyer alongside the DPE. Apartments in a co-ownership are exempt. From 2034 houses rated D will be included too.
Can a chalet rated F or G be sold?
Yes. There is no ban on selling, at any rating. The restrictions that tighten over time apply to letting. Expect the rating to feature in the negotiation, and expect to supply the energy audit.
Where this leaves you
If you are thinking of selling a chalet or a mountain house in the valley, the certificate is worth sorting out before the property goes live rather than during the sale. We will tell you which threshold scale applies to your altitude, whether a free refresh would move your label, and what the rating is likely to do to your asking price. That conversation is free and carries no obligation.