RE2020 (Regulation)

RE2020 is the French regulation governing new buildings (and certain extensions) since 2022, replacing RT2012. It goes beyond simply measuring kWh: it mandates energy efficiency through design (Bbio), measured energy performance (including Cep/Cep,nr), quantified summer comfort (DH – degree-hours), and, most importantly, a carbon footprint assessment over the life cycle of materials and systems (Ic energy & Ic construction). The goal: more energy-efficient buildings, more comfortable during warmer periods, and with a lower carbon footprint from the design stage.

RE2020: Definition and scope

The RE2020 regulation relies on regulatory models and product data (FDES/EPD) to verify:

- Bbio ≤ Bbiomax: intrinsic needs (heating, cooling, lighting) reduced by the architecture and the envelope (Ubat, g/TL, solar protections, inertia, compactness).

- Summer comfort: Downhill below a threshold (external protections, night-cooling, inertia).

- Energy: Cep/Cep,nr with regulatory scope (heating, cooling, DHW, lighting, auxiliaries).

- Carbon: Ic energy (use of systems) and Ic construction (materials over life cycle).

The process produces certificates (permit filing, completion), cross-references plans and descriptions, and requires traceability of performance (supplies installed, environmental data sheets) to match the calculation.

Designing under RE2020: benefits, limitations and points to consider

Benefits

• Comprehensive view: energy and carbon + summer better represented (DH).
• Encourages good choices: continuous envelope, external protections, useful inertia, local renewable energy sources.
• Better resilience: buildings are more stable in the face of heat waves and energy prices.

Boundaries

• Standardization: like any conventional method, it does not reflect 100% of actual usage (times, densities).
• Product data: the availability/quality of FDES may constrain choices.
• Iterative: several loops of optimization and justification (study time/cost).

Points to consider

• “Bbio first” design: low Ubat, treated thermal bridges (Ψ/χ), g/TL adapted per façade, controlled external protections.
• Summer comfort: aim for low DH via BSO, awnings, night ventilation, light colours, inertia (exposed slabs).
• Energy: low temperature emitters, recovery (air/water), BMS/EMS for schedules & capping; align self-consumption with the profile.
• Carbon: arbitrate between structure/secondary work (low-carbon concrete, wood, reuse), optimize thicknesses and durability (Ic construction).
• Site traceability: what is installed must equal what is calculated (sheets, photos, test reports, marking).
• Validation: use STD/SED to objectify DH and peaks, not just annual kWh.

Anecdote — “The construction site that lasted all summer in Bordeaux”

In Bordeaux, a heavily glazed office building facing southwest failed to meet either the DH (Dynamic Heat Loss) or Ic (Construction Energy Consumption) standards. The team replaced some of the window frames with selective glazing (TL ~60%, g ~0.35) and added external adjustable sunshades controlled by the building management system (BMS), while also converting the floor structure to low-carbon concrete. The result after recalculation: DH compliant, Cep,nr (primary energy consumption, net irradiance) reduced, and Ic construction met without additional insulation thickness. A year later, the offices remained comfortable during heat waves, and the energy bill didn't skyrocket. The moral of the story: in RE2020 regulations, well-managed shading and carefully chosen materials are worth more than powerful compressors.