2017-09-07
Energy Efficiency Regulations for Existing Buildings
(RTex) 2018/2023: What’s the Impact on Opaque Building Elements?
Construction, France’s most energy-intensive industry, represents 45% of the country’s power consumption. With the goal of 500,000 renovated housing units per year and entirely energy-efcient existing buildings by 2050, building performance is a major issue addressed by the French law on energy transition for green growth.
Successive government orders have raised requirements for thermal performance and therefore the energy efficiency of existing buildings. Here’s a close-up of evolving RTex for thermal resistance of opaque building elements, taking effect on January 1, 2018.
Regulations for overall energy efficiency and for individual building elements
Overall energy efficiency regulation apply to existing buildings with surfaces greater than 1,000 m2 and those where renovations represent more than 25% of construction costs. If either of these two criteria is not met, the regulation apply to individual building elements. The frst such regulation for individual building elements dates to 2007 (order of May 3, 2007). It was recently amended by the order of March 22, 2017.
What does the order of March 22, 2017, which goes into effect on January 1, 2018, change?
- Requirements based on precise breakdown of climatic zones: Zone H1 (“H” for hiver, or “winter”), the coldest in mainland France, is the most stringent.
- Strengthening of RTex requirements in 2 phases.
January 2018: Energy efficiency requirements for renovated elements will rise, on average, by about 15%. Floors over crawl spaces or unheated spaces are subject to the highest increase in performance levels (35%), followed by flat roofs (32%).
Janvier 2023 par rapport à 2018 : le renforcement des exigences augmentera à nouveau d'environ 15 % en moyenne sur l'ensemble des parois.
January 2023 compared with 2018: Requirements will rise again by about 15% on average for all building elements. The greatest impact is on flat roofs, with new standards 36% more strict than 2018.
Find out more: Table on RTEX requirements for individual building elements
Technical requirements
This gradual change in energy efficiency regulations for existing buildings, spread over four years, enables manufacturers to prepare and adjust their products and insulation techniques to meet the new requirements of the 2023 renovation market. ACERMI certification assists construction industry stakeholders in meeting the terms of the new regulations.
RTEX REQUIREMENTS FOR INDIVIDUAL BUILDING ELEMENTS
| BUILDING ELEMENTS |
YEAR OF APPLICATION |
MINIMUM THERMAL RESISTANCE OF RENOVATED WALL (m².K/W) |
ADJUSTMENT | ||
|---|---|---|---|---|---|
|
H1 a, b, c |
H2 a, b, c, d H3 > 800 m |
H3 < 800 m |
|||
| Wall and roof pitch > 60° | 2007 | 2,3 | 2,3 | 2,3 | 2.0 (H3 < 800 m; −5% Usable Floor Area; double-walled metal panel) |
| 2018 | 2,9 | 2,9 | 2,2 | - | |
| 2023 | 3,2 | 3,2 | 2,2 | 3.2 (Internal wall insulation, double-walled metal panel) | |
| Walls in contact with unheated spaces | 2007 | 2,0 | 2,0 | 2,0 | - |
| 2018 | 2,0 | 2,0 | 2,0 | - | |
| 2023 | 2,5 | 2,5 | 2,5 | - | |
| Flat roofs | 2007 | 2,5 | 2,5 | 2,5 | 1,5 (technical effects related to insulation thickness) |
| 2018 | 3,3 | 3,3 | 3,3 | 3,0 (technical effects related to insulation thickness) | |
| 2023 | 4,5 | 4,3 | 4,0 | 3,0 (technical effects related to insulation thickness) | |
| Unused attics | 2007 | 4,5 | 4,5 | 4,5 | - |
| 2018 | 4,8 | 4,8 | 4,8 | - | |
| 2023 | 5,2 | 5,2 | 5,2 | - | |
| Roof pitch < 60° | 2007 | 4,0 | 4,0 | 4,0 | 3,0 (−5% Usable Floor Area) |
| 2018 | 4,4 | 4,3 | 4,0 | 4,0 (−5% Usable Floor Area) | |
| 2023 | 5,2 | 4,5 | 4,0 | 4,0 (−5% Usable Floor Area) | |
| Low floors leading outside or to parking lot | 2007 | 2,3 | 2,3 | 2,3 | 2,0 (H3 < 800 m; min. ceiling height requirement; installation or replacement of heated floor) |
| 2018 | 2,7 | 2,7 | 2,1 | 2,1(min. ceiling height requirement) | |
| 2023 | 3,0 | 3,0 | 2,1 | 2.1 (min. ceiling height requirement) | |
| Low floors over crawl spaces or unheated spaces | 2007 | 2,0 | 2,0 | 2,0 | R reduced if installation or replacement of heated floor |
| 2018 | 2,7 | 2,7 | 2,1 | 2,1 (min. ceiling height requirement) | |
| 2023 | 3,0 | 3,0 | 2,1 | 2,1 (min. ceiling height requirement) | |
RTex applies to renovations, except when such work is done following a weather-related incident (for example, a storm) or damage due to vandalism (Order of May 3, 2007, Order of March 22, 2017).
