RT2012 (Thermal Regulation 2012)

The RT2012 (Thermal Regulation 2012) governed the energy performance of new buildings in France for permits filed from 2013 onwards, before being replaced by the RE2020 for new projects. It set a primary energy consumption ceiling and requirements for bioclimatic design, summer comfort, and airtightness. Even though the RE2020 is now the standard, the RT2012 remains useful to understand for analyzing buildings delivered under this regulation, processing amendments to still-valid RT2012 permits, or comparing performance levels.

RT2012: Definition and Scope

The RT2012 regulation relied on a regulatory calculation engine (Th-BCE 2012 method) and notably imposed:

- Cep ≤ 50 kWhEP/m².year on national average, modulated according to climate, altitude, use and surface area.

- Bbio (bioclimatic need) ≤ Bbiomax: sobriety through design (envelope, solar inputs, light).

- Tic (conventional indoor temperature) for summer comfort.

- Air tightness measured (blower-door test) on residential buildings.

- Share of renewable energy in individual houses (e.g., solar, heat pump, grid, etc.).

- Minimum glazed area (≈ 1/6 of the living area) to promote natural light.

- Treatment of thermal bridges and insulation requirements.

This framework applied to most new residential and commercial buildings. Since 2022, new building permits have been subject to RE2020 ; however, RT2012 may still be the reference for earlier permits or certain amendments, depending on the processing date.

Requirements, limitations and points of attention of RT2012

Interests / contributions

• Created a national performance benchmark, significantly reducing consumption compared to previous standards.
• Structured the bioclimatic design via the Bbio (orientation, solar factors, inertia).
• It disseminated best practices: airtightness, thermal bridges, natural light.

Boundaries

• Indicators focused on primary energy (not carbon from materials/systems, now dealt with by RE2020).
• Simplified Tic for summer, less representative than the DH (degree-hours) taken into account today.
• Heterogeneity of actual quality depending on execution (calculated performance ≠ field if details are neglected).

Points of attention (existing RT2012 buildings)

• Settings/BMS: water laws, schedules, sun protection to maintain summer comfort.
• Field checks: leak tests, thermography, HVAC balancing to bring reality closer to calculation.
• Renovations/evolutions: in case of extension or change of use, check the applicable regime (RE2020, existing RT) and the impact on Cep and comfort.
• Comparisons: for calls for tenders, specify whether the reference is RT2012 (historical) or RE2020 (current), in order to avoid misunderstandings about targets.

Anecdote — “A finishing touches project completed in Dijon”

In Dijon, a building compliant with RT2012 standards, delivered in 2018, was accumulating summer complaints. The audit revealed: poorly configured solar shading, air inlets too open during heat waves, and a heating curve unchanged since commissioning. Without major renovations, the building manager adjusted the building management system (BMS) scenarios (automatic closure of external blinds during peak sunlight, nighttime ventilation as soon as the outside air is cooler) and optimized airflow rates. The result: reduced heating costs, restored comfort, and stabilized bills. The moral of the story: in both RT2012 and RE2020 regulations, proper control often makes the difference between theory and practice.