The building sector accounts for 44% of annual energy consumption in France and 25% of greenhouse gas emissions. Against this backdrop, RE2020 sets out a more stringent legal framework for environmental protection. It focuses on three new objectives: ensuring summer comfort, reducing the carbon impact of new buildings, and optimizing their energy performance. For the latter, it strengthens the requirements of its indicators and introduces new ones. So how does RE2020 measure the energy performance of buildings?
Background and challenges
RE2020 complies with the Energy Transition for Green Growth Act and the Housing, Planning, and Digital Development Act (ELAN 2018).
Its objective is to continue improving the energy performance and comfort of buildings, while reducing their carbon impact. It is structured around three main areas:
- Continue to improve energy performance and reduce consumption in new buildings. RE2020 goes beyond the requirements of RT2012, placing particular emphasis on insulation performance regardless of the heating system installed, thanks to stricter requirements for the bioclimatic need indicator, Bbio.
- Reduce the climate impact of new buildings by taking into account all emissions generated by the building throughout its life cycle, from the construction phase to the end of its life (construction materials, equipment), including the operational phase (heating, domestic hot water, air conditioning, lighting, etc.), using a life cycle analysis.
- Enable occupants to live and work in environments adapted to future climate conditions, while maintaining comfort in summer. Buildings will need to be more resistant to heat waves, which will become more frequent and intense as a result of climate change.
RE2020is based on a gradual transformation of construction techniques, industrial sectors, and energy solutions in order to control construction costs and ensure that professionals develop their skills.
How is energy performance taken into account?
As with RT2012, RE2020 continues to improve energy performance and reduce consumption in new buildings. The five regulatory uses of RT2020 (heating, lighting, domestic hot water production, and auxiliary equipment) are still present, but RE2020 adds the mobility of the building's internal occupants (elevators, escalators) and other auxiliary equipment (parking lots and common areas in multi-unit buildings). The method for calculating energy performance therefore uses algorithms that are identical or similar to those used in RT2012, with a few adaptations and additions.
Energy performance measurement indices under RE2020
The Bbio index
The bioclimatic needs indicator (Bbio) represents the energy requirements of a building for heating, cooling, and lighting. Already used in RT2012, its requirements have been strengthened in RE2020 with the systematic consideration of cooling needs (whether or not an air conditioning system is installed, cooling needs will be calculated).
High Bbio performance is achieved by optimizing the building structure independently of the energy systems used: taking into account the orientation and layout of windows to maximize solar gain while providing protection in summer; working on lighting; limiting heat loss through compact volumes and good insulation of opaque surfaces (walls, slabs, and roofs) and windows.
In RT2012, cooling requirements were only taken into account in the calculation when the designer chose to install an air conditioning system. With RE2020, this cooling requirement is systematically included in the calculation, even if no air conditioning system is planned.
The goal is to optimize the building's design in terms of both winter and summer performance.
Everything you need to know about the Bbio in RE2020 >
The Cep index
The conventional energy consumption indicator (Cep) measures the energy consumption of heating, cooling, domestic hot water, lighting, ventilation, and auxiliary equipment. With RE2020, additional building uses are added.
With this indicator, RE2020 broadens its scope, strengthens its requirements on equipment efficiency, and encourages self-consumption of electricity and heat recovery.
For all energy sources used to meet the needs of conventional consumption items expanded since RT2012, both renewable and non-renewable sources are taken into account. The Cep calculation only takes into account imported energy (renewable or non-renewable) needed to meet the building's needs. The indicator therefore does not take into account renewable energies captured on the building's plot.
Self-consumption of photovoltaic electricity production or heat recovered on the building's plot is not considered imported energy and is therefore not included in the calculation.
Thus, their benefits are taken into account in RE2020 because they reduce the Cep. However, with a view to promoting the potential for self-consumption, energy exports are not taken into consideration in RE2020.
Find out everything you need to know about the RE2020 Cep index >
The Cep index,nr (new)
The conventional non-renewable energy consumption indicator (Cep,nr) represents the building's primary non-renewable energy consumption for the same uses as the Cep. This indicator therefore only takes into account non-renewable energy sources used to meet the building's needs.
For example, wood consumption will not be taken into account in the calculation of the indicator, nor will the renewable share of heat supplied by a heating network.
With this new indicator, RE2020 differs from RT2012 and encourages the use of renewable energies via an ambitious maximum threshold for non-renewable primary energy consumption.
To learn more about the Cep,nr index of RE2020 >
TheICénergie index (new)
TheICénergie indicator represents the impact on climate change of energy consumption during the lifetime of a building, i.e., 50 years. This index was created with RE2020 and encourages the use of carbon-free energy sources. It is therefore both an energy and environmental indicator.
For the first time, regulations set a maximum threshold for greenhouse gas emissions from energy consumption. Although its performance is viewed from the perspective of greenhouse gas emissions, it is an indicator of energy consumption performance (the levers for action are very similar to those for the Cep).
Find out everything you need to know about the RE2020ICénergie index >
Improving the energy performance of new buildings is a major challenge for RE2020. The objective is twofold: the construction sector must reduce its impact on the environment and buildings must reduce their energy consumption, while promoting carbon-free resources as much as possible. With the RE2020 environmental regulation, the environmental performance of buildings is at the heart of the results and requires the support of trained and qualified professionals from the design stage onwards.
