RE2020: What It Actually Means If You're Building in France
France replaced its thermal building regulations in 2022. If you're building new, you're under RE2020. Here's what it requires, why it exists, and where it's heading.
From RT2012 to RE2020: What Changed
The old rules, RT2012 (the Réglementation Thermique), asked one question: how much energy does your building consume? Stay under the threshold, you're compliant.
RE2020 kept that logic, then added something the old rules ignored entirely: carbon. Not just how efficiently your building runs in use, but the environmental cost of building it in the first place. The concrete, the insulation, the structural frame all carry a carbon footprint before a single person moves in.
That's the shift. RE2020 is a Réglementation Environnementale, environmental not just thermal. Energy performance is still there, but it's one part of a bigger picture that now includes a full lifecycle carbon analysis of the building over 50 years.
The Six Indicators (Under Four Themes)
RE2020 measures six things, grouped into four themes:
Comfort DH (Degrés-Heures): summer overheating expressed in degree-hours of discomfort above a comfort threshold (26°C at night, adaptive up to 28°C during the day). Calculated using heatwave weather data, not average conditions. For a typical maison individuelle, the upper limit is 1,250 degree-hours in category 1 (no external constraints) and 1,850 in category 2 (external noise constraints preventing natural ventilation).
Bioclimatic design Bbio (Besoin bioclimatique): the intrinsic energy need of the building based purely on its design, covering orientation, glazing, insulation, and thermal mass. The base value for a maison individuelle is 63 points, modulated by geographic zone, loft space, floor area, and proximity to road noise. Calculated before you've chosen a heating system. Locked in at permit stage: get your Bbio wrong and no heating system will save you.
Materials IC Construction: the carbon footprint of the building's materials and construction site over a 50-year lifecycle, calculated using dynamic lifecycle assessment (ACV dynamique). This is the genuinely new element. Nothing like it existed in RT2012.
Energy Three indicators covering operational energy and carbon:
- CEP: total primary energy consumption across heating, cooling, hot water, ventilation, lighting, and lifts. Base value for a maison individuelle: 75 kWhep/m²/year
- CEP,nr: the non-renewable fraction. Base value for a maison individuelle: 55 kWhep/m²/year. A heat pump on the French grid scores well here. Gas does not.
- IC Énergie: the carbon impact of operational energy consumption over 50 years. For maisons individuelles: 160 kgCO2/m²
Thresholds: It's Not One Number
Every project gets its own maximum value, calculated from a base figure modulated by coefficients covering geographic location and altitude (Mbgéo / Mcgéo / Migéo), loft space, average apartment area, total floor area, road noise exposure, and for IC Construction, foundation complexity, VRD infrastructure, and photovoltaic installation.
So "what's the RE2020 threshold for IC Construction?" doesn't have a single answer. Your thermal engineer calculates the project-specific maximum. What is fixed: the base values and the schedule on which they tighten.
What This Means on Site: The Practical Stuff
The envelope comes first
Bbio is submitted at permit stage and locked in. You can't retrofit your way to a better Bbio: the geometry, orientation, and insulation levels are baked into the design from the outset.
The common mistake is designing the house first, then asking the thermal engineer to make it pass. It works, but it costs more and produces worse buildings. Bbio logic should be influencing room placement, window sizing, and roof overhangs from day one.
Heating systems and the carbon bias
RE2020 strongly favours heat pumps over gas. France's electricity grid is predominantly nuclear, which means low carbon intensity. Electricity carries a primary energy conversion factor of 2.3 in RE2020, but its CO2 factor is low enough that a heat pump running on French electricity scores significantly better on both CEP,nr and IC Énergie than a gas condensing boiler.
From 2025, the IC Énergie thresholds for collective housing tightened enough that gas as a sole heating source is effectively no longer viable for compliance. For maisons individuelles the IC Énergie threshold holds at 160 kgCO2/m², but the CEP,nr constraint does the same work.
Biosourced materials and the dynamic ACV advantage
RE2020 uses a dynamic lifecycle assessment method that weights emissions by when they occur. An emission today counts more than the same emission in 50 years. Materials that sequester carbon, including timber, hemp concrete, and straw, carry a negative carbon impact in the calculation because the stored carbon is credited against the building's IC Construction score.
A timber frame house can achieve IC Construction figures well below the required thresholds. The official ministry guide notes that timber construction, currently under 10% of new individual houses, will likely become standard practice by 2030, a direct consequence of where the carbon thresholds are heading.
Summer comfort is now measured and regulated
The DH indicator catches a real problem that plagued some well-insulated RT2012 houses: perfectly warm in winter, unbearably hot in July. Good solar shading, correct window placement, and thermal mass all contribute to keeping DH under the threshold. If DH falls between the low threshold (350 degree-hours) and the upper limit, the building complies but a cooling penalty is added to the CEP calculation, an incentive to go further with passive design.
The Tightening Schedule: 2025, 2028, 2031
RE2020 is not a fixed target. It's a roadmap with tightening built into the original decree. The base values for IC Construction are:
| Period | Maison individuelle | Logement collectif |
|---|---|---|
| 2022-2024 | 640 kgCO2eq/m² | 740 kgCO2eq/m² |
| 2025-2027 | 530 kgCO2eq/m² | 650 kgCO2eq/m² |
| 2028-2030 | 475 kgCO2eq/m² | 580 kgCO2eq/m² |
| 2031+ | 415 kgCO2eq/m² | 490 kgCO2eq/m² |
These are base values before geographic and project-specific modulation. The trajectory aligns with France's Stratégie Nationale Bas Carbone. It was in the decree from day one.
Beyond RE2020, the CAP 2030 framework is in development: a voluntary reference framework exploring broader environmental themes (biodiversity, circular economy, water management) that will inform whatever regulation comes next.
What This Means If You're Planning a Build Now
Your permit is filed under thresholds current at the date of submission. But if construction takes time, you could be building under 2028 rules before the roof goes on. Worth knowing.
More practically, designing to 2028 standards now costs very little extra at design stage. A better-specified wall build-up, a heat pump instead of gas, a more considered window layout: these decisions are cheap on paper and expensive once the walls are up.
The RE2020 envelope tool on this site lets you test different wall, floor, and roof compositions against your project's specific targets. If you're at early design stage and want to understand your thermal margins before committing to a structural system, that's where to start.