France's RE2020 completion attestation covers six result areas: bioclimatic need, primary energy, non-renewable primary energy, summer comfort, carbon from energy use and carbon from building components and construction. The Ministry's official attestation guide says the document is supported by the standardised energy and environmental study and a site visit.
That is considerably more useful than a brochure describing a development as efficient, responsible or low consumption. Those words have no unit. RE2020 has calculations, thresholds and evidence. A buyer's task is to find out how the regulatory model has shaped the apartment they will actually receive.
RE2020 is a building calculation
The regulation applies to new construction under the relevant permit and building category. It assesses the proposed building through climate, orientation, envelope, systems and materials. The result is not a guarantee of one household's future utility bill. Occupancy, thermostat settings, ventilation habits and weather still matter.
For an apartment buyer, the distinction is important. A development can comply as a building while individual flats have different solar gain, aspect and heat loss. Ask for the project's regulatory summary and the dwelling-level energy information where available. Then relate it to the plan.
RE2020 also evolves through staged requirements. The Ministry published a simplification decree on 31 December 2024 and began preparing the next milestone scheduled for 1 January 2028. Buyers should use the rule applicable to the project's permit and not assume a delivery year automatically moves an older consent to a later threshold.
Ask for the permit date and any amending permits, then have the developer identify the applicable calculation version in writing. “Delivery in 2028” and “designed to the 2028 milestone” are different statements.
Start with the bioclimatic design
The Bbio indicator addresses the building's intrinsic need for heating, cooling and lighting. In Alpine construction, that brings the envelope into focus: insulation continuity, glazing, airtightness, orientation and thermal bridges. A powerful heating system cannot repair a weak fabric calculation.
Ask which elevations carry the most glazing and how balconies, slab edges and roof junctions are treated. Large mountain-facing windows can create winter pleasure and summer overheating. Triple glazing may improve one measure while frame quality and installation determine the real junction performance.
The useful documents are sections, façade details and the thermal study, not a single wall-thickness number. Two assemblies with the same insulation depth can perform differently because of material, continuity and moisture design.
Heating deserves a system diagram
RE2020 limits energy use and the carbon impact associated with it. Developers may choose heat pumps, district networks, biomass, electric systems or combinations. The buyer needs to know what is communal, what is private and how use is metered.
Request a plain diagram: heat source, distribution, hot water, controls, metering, backup and maintenance responsibility. Then ask for expected service contracts and the allocation method in the draft copropriété budget. A low-carbon communal system with expensive fixed maintenance may still be the right engineering choice, but it belongs in the ownership forecast.
Mountain homes can be occupied intermittently. Find out whether frost protection, remote control and hot-water recovery suit that pattern. A system optimised for permanent occupation may behave differently when a flat is empty from Monday to Friday and full of eight guests at the weekend.
Summer comfort is now a buying issue
RE2020 includes a summer-comfort indicator because overheating is no longer a problem reserved for the Mediterranean. High insulation, large glazing and warmer summers can produce uncomfortable apartments even at altitude.
Ask the developer for the assumed shutters, blinds, solar-control glass and ventilation strategy. Check whether external shading is included in the contractual specification or merely shown in an image. Ask how top-floor and west-facing units performed in the summer model.
Mechanical cooling is not the only answer and may not be permitted or desirable. Night ventilation, opening area, shading and exposed thermal mass can do substantial work. Yet they have to exist in the delivered design. A buyer cannot operate a night-purge strategy through a fixed pane.
Carbon sits inside the material choices
RE2020 extends beyond operational energy to the climate impact of components and construction. Structure, insulation, façades, finishes and equipment contribute to the life-cycle calculation. Timber can help, but “timber-clad” says little about the structure behind the cladding.
Ask which parts are concrete, masonry or timber; which environmental product declarations underpin the study; and which substitutions the developer may make. A VEFA specification usually allows equivalent products. Equivalence should preserve performance, durability and appearance rather than price alone.
The Ministry's RE2020 overview describes the three policy objectives as reducing building energy use, reducing life-cycle carbon and improving comfort during hot conditions. Those objectives form a useful agenda for the specification meeting.
The paper trail has three dates
At reservation, ask for the notice descriptive, planning drawings and headline energy strategy. Before the notarial sale, check that the contractual documents match the marketed system and finishes. At handover, request the completion attestation, final energy certificate, equipment manuals, commissioning records and evidence for any post-contract substitution.
The digital housing information log, or carnet d'information du logement, should also receive attention. Service-Public says that, in a VEFA purchase, the developer must transmit the relevant information to the owner by delivery. Ask what the handover pack will contain and who updates it after later energy work.
The completion attestation can be prepared for the developer by an architect, control office, certifier or, in limited housing cases, a qualified energy assessor. It is attached to the declaration of completion and conformity. It is regulatory evidence, not a snagging survey. The buyer still needs to inspect finishes, operation and defects.
Keep versions. If the reservation brochure says timber windows, the notarial notice says aluminium and the delivered manual names a third product, the chronology matters. Sales material is not always contractual; inconsistencies should be resolved before signing.
Compare two flats, not two labels
Imagine two €500,000 apartments, each advertised as RE2020 compliant. Flat A has south-west glazing, external shutters, a private heat-pump unit and modest charges. Flat B has north-east glazing, communal heating, a staffed spa and higher charges. Compliance does not make them financially or experientially equal.
Nor does it answer acoustics. Plant rooms, lifts, waste areas and commercial units can affect a holiday flat as much as heat demand. Request the acoustic specification and inspect the plan for junctions with communal equipment. A quiet building is an ownership benefit and a rental asset.
Moisture is another Alpine concern. Ask how wet ski clothing is ventilated, where extract air discharges and how below-ground walls and balconies are waterproofed. These questions sit beside RE2020 rather than inside one performance number.
Build a scorecard: winter heat demand, summer-control measures, metering, fixed service cost, ventilation, acoustic design, maintenance access and replacement responsibility. Add the view, location and plan afterwards. A technical regulation narrows bad outcomes; it does not select the better home.
The Ministry's 2025 update also adjusted treatment for certain small units under 40m² and projects using renewable or network heat. Small ski apartments therefore deserve particular attention to the project-specific study rather than a rule of thumb.
Make performance part of the purchase file
Ask six direct questions: which RE2020 regime applies; who produced the study; what heating and hot-water system is contracted; how summer comfort is controlled; which material substitutions are permitted; and which documents arrive at handover. Record the answers in writing.
Request the regulatory study summary, the completion attestation, the final energy certificate and the equipment commissioning records. Availability changes by stage, so the reservation response may be a commitment to deliver rather than the final document. Put that commitment into the file.
Where an answer is unavailable, record who will provide it and by which contractual milestone. A missing final certificate before construction is normal; no named route to obtain it is not.
That written schedule should stay with the reservation file, not in a salesperson's inbox.
Then compare the technical offer with the price, service charges and location. Domosno's current French Alps new builds span different climates, scales and specifications. A €6,000 per m² valley apartment and a €20,000 per m² high-resort residence should both satisfy the law; the premium must be explained elsewhere.
Domosno can obtain the plans, notice descriptive and programme information for a shortlist and help identify the questions that remain. Contact the team before treating an environmental label as a complete technical answer.
