Can an open database verify claims about a new apartment’s comfort and efficiency? OPEE offers reference points for comparing projects. For a particular apartment, the answer comes from its technical documents and contractual commitments.
Distinguish the PC and DAACT stages in OPEE. PC refers to the building-permit stage; DAACT to the declaration of completion and conformity. CSTB explains the stages, revised calculations and anonymisation. An open-data record cannot establish that the developer has met the obligations for your apartment: obtain its project documents.
What is available
On 3 September 2026, the ministry announced the release of OPEE data on new buildings’ energy and environmental performance. The CSTB portal shows a 1 September update. Collective housing is included, with submissions from different project stages, including completion.
OPEE indicators are calculated values, including those for completed buildings. They help compare projects’ energy and environmental characteristics. Estimate the owner’s future bills separately using actual occupancy assumptions and tariffs.
Use comparisons to ask better questions
When buying off-plan under a French VEFA contract, start with the specification and its contractual commitments. OPEE can provide context on construction choices, carbon indicators and summer comfort.
| Subject | Question for the developer |
|---|---|
| Energy consumption | Which indicator, floor-area definition and energy uses are included? |
| Carbon performance | What are the calculation boundaries and document stage? |
| Summer comfort | What shading, ventilation and cooling assumptions were used? |
| RE2020 compliance | Which requirements apply to this project’s permit date? |
Compare similar building types, climate conditions and regulatory versions. Without these controls, a ranking may reflect the sample rather than a meaningful performance difference.
Understand the limits
The anonymised dataset covers some projects and supports comparisons between groups of buildings. To verify the chosen apartment, use its developer’s calculations, certificates and specification. Start by selecting comparable building types, climate zones and RE2020 regulatory periods in the dataset.
Request the applicable calculations and attestations, technical specification, heating and ventilation details, and the installed-equipment documents at handover. Check which version is current when materials or systems change.
The outcome is a list of features supported by the chosen development’s documents and questions the developer has yet to answer. Clarify an ambiguous advertising claim before selecting the project. Estimate likely running costs separately using the intended occupancy and tariffs.
How comfortable will your own rooms be?
Once the calculated indicators are clear, how do you assess summer comfort with the chosen apartment’s windows, shade and your intended use? Our home checks after a hot summer explain what to examine across the day: sun protection, night-time ventilation, cooling and costs.
For an apartment under construction, start with the plans and specification, noting what can only be checked during a viewing. For a completed home, carry out the checks on site. Ask the developer to clarify any uncertain features and refer the necessary calculations to a technical specialist.
How are the promised features of your unit documented?
Compare calculations with the plans and specification using the VEFA guide. Share the development and the features that matter to you so we can distinguish contractual commitments, completion evidence and checks needed at handover.
Sources and verification date
Checked on 22 September 2026. Observation periods and limitations are identified in the article.
