One of the objectives of RE2020 is to reduce the environmental impact of new buildings, which are responsible for 25% of CO2 emissions in France. Bioclimatic design is at the heart of the challenges facing professionals in the sector. So what are the main drivers for carbon-free construction?
1. Energy efficiency in buildings
Thermal insulation
One of the first steps towards carbon-free construction is to improve the thermal insulation of buildings. By investing in high-performance insulation materials, heating and air conditioning requirements are reduced, thereby lowering energy consumption.
Thermal insulation is an important consideration, particularly given the increase in the frequency and duration of heat waves in recent years. RE2020 encourages the inclusion of summer comfort in these objectives, notably with the introduction of a new indicator, the Degree-Hour (DH) of discomfort.
Using high-performance materials for building insulation can reduce the need for electric heating and/or air conditioning units.
Use of smart technologies
The integration of smart technologies, such as automated energy management systems, is another lever that can be used to optimize energy consumption based on actual needs.
These systems use sensors, monitoring devices, and advanced algorithms to collect real-time data on a building's energy consumption. This data is collected continuously to obtain an accurate picture of the building's energy needs.
They also enable the analysis of energy consumption patterns over a given period. They can then automatically adjust the settings of heating, ventilation, air conditioning, and lighting systems. This optimizes equipment performance based on the building's actual needs, thus avoiding unnecessary overconsumption.
By optimizing systems in real time, smart technologies reduce energy waste by preventing unnecessary overconsumption, resulting in significant financial savings and a reduced carbon footprint.
To learn more about measuring a building's energy performance in the RE2020 era >>
2. Renewable energy
Solar panels
The installation of solar panels on building roofs is one of the drivers of carbon-free construction.
Solar panels provide a renewable energy source, helping to reduce dependence on fossil fuels while lowering the building's CO2 emissions. They are made up of photovoltaic cells that convert sunlight into electricity. When sunlight hits these cells, it excites the electrons, generating an electric current. This direct conversion of solar energy into electricity is a clean and renewable source of energy.
Installing solar panels on building roofs creates a local source of energy. This reduces dependence on centralized energy sources by promoting decentralized and distributed production. Furthermore, using solar energy to generate electricity does not produce greenhouse gases.
By replacing electricity generated from fossil fuels with that from solar panels, we directly contribute to reducing carbon dioxide (CO₂) emissions into the atmosphere, thereby helping to mitigate climate change. Unlike fossil fuels, solar energy is an inexhaustible resource. The sun is a constant and sustainable source of energy, and solar panel technology allows this energy to be captured efficiently.
Urban wind turbines
In certain urban areas, the use of small wind turbines (also known as domestic or urban wind turbines) also contributes to renewable energy production and is proving to be one of the drivers for carbon-free construction.
The integration of wind turbines into a building's energy production offers a sustainable and renewable alternative, contributing to the reduction of CO2 emissions and the transition to a more environmentally friendly energy model.
Similar to solar panels, domestic wind turbines capture the kinetic energy of the wind and convert it into electricity using rotating blades connected to a generator. Even on a small scale, they can generate enough electricity to meet the energy needs of a building, including lighting, electronic devices, and other equipment.
By using wind energy to generate electricity, we avoid burning fossil fuels, which directly contributes to reducing CO2 emissions. Wind energy is considered a clean and renewable energy source, producing no greenhouse gases during its operation.
3. Bioclimatic design
Bio-based materials
The use of bio-based building materials, such as wood or cellulose insulation, is an effective strategy for reducing the carbon footprint of construction by storing carbon, minimizing embodied energy, and promoting sustainable and resource-efficient life cycles.
Bio-based materials act as carbon sinks.
For example, trees absorb carbon dioxide (CO₂) from the atmosphere as they grow, storing carbon in their structure. When wood is used as a building material, this carbon is sequestered, contributing to a net reduction in CO₂ emissions in the atmosphere.
In addition, bio-based materials generally have lower embodied energy than conventional materials, as their production often requires less non-renewable energy. The use of these bio-based materials also reduces dependence on non-renewable resources, such as fossil fuels used in the production of conventional materials. This contributes to the preservation of these limited resources.
The manufacture of bio-based materials generally emits less greenhouse gases than the production of conventional materials. For example, the manufacture of cellulose insulation a virtuous dry process, involving simple mechanical grinding. Neither water nor heat are required, which means that cellulose insulation has cellulose insulation negative impact on the environment.
Bio-based building materials also have a longer life cycle (around 50 years) and their raw materials are naturally renewable. In addition, these materials are often recyclable or biodegradable at the end of their life. Finally, some bio-based materials, such as cellulose insulation, are also excellent thermal insulators. By improving the energy efficiency of buildings, they reduce dependence on heating and air conditioning systems, which translates into lower energy consumption.
Bioclimatic design
Bioclimatic design is the main lever for reducing a building's carbon footprint. It takes local climate characteristics into account to maximize natural benefits such as sunlight and wind, thereby minimizing its environmental impact.
For example, bioclimatic design maximizes the use of natural light to reduce dependence on artificial lighting. This reduces the amount of electricity needed for lighting, thereby reducing CO2 emissions associated with electricity generation.
By taking advantage of natural ventilation and designing appropriate ventilation systems, bioclimatic design promotes air circulation without resorting to energy-intensive mechanical systems. This helps reduce the energy consumption required for heating, air conditioning, and ventilation.
Bioclimatic design also incorporates passive thermal management strategies, such as building orientation, the use of materials with high thermal inertia, and the installation of shading devices. These elements help maintain a comfortable indoor temperature without resorting to excessive energy consumption for heating or cooling.
Bioclimatic design also promotes the use of sustainable, low-carbon building materials. By favoring bio-based materials, bioclimatic design reduces CO2 emissions associated with the manufacture and transport of building materials.
To understand how RE2020 measures the environmental impact of a new building >>
4. Electrification
Electric heating
Replacing gas heating systems with electric solutions powered by renewable energy helps reduce CO2 emissions. It is one of the most effective levers for carbon-free construction.
For example, geothermal heat pumps use energy stored in the ground to heat or cool a building.
Solar water heaters can also be an effective lever: they capture the sun's energy to heat water. These systems are widely used in homes and businesses to replace gas water heaters, thereby reducing fossil fuel consumption.
As we have also seen, using electricity from renewable sources, such as solar or wind power, for electric heating can replace gas heating systems and thus reduce CO2 emissions associated with the combustion of natural gas.
Another lever is induction cooktops, which run on electricity and are more energy efficient than gas cooktops. Finally, the use of electric cooling systems powered by renewable energy, such as heat pumps, can replace gas cooling systems, thereby reducing a building's carbon footprint.
Decarbonizing construction in France is a major challenge, but the levers mentioned above offer concrete solutions for reducing CO2 emissions. By combining energy efficiency, the use of renewable energy sources, bioclimatic design, and electrification, construction professionals can drastically reduce the sector's carbon footprint.
