The Environmental Regulation 2020 (RE2020) represents a major step in sustainable construction in France. It sets new requirements to reduce the environmental impact of new buildings, particularly in terms of energy consumption. This article explores how to calculate your RE2020 kWh/m2/year consumption to meet these new standards.

Key Points to Remember

• RE2020 replaces RT2012 and aims for a significant reduction in buildings’ energy needs, with an emphasis on efficiency and the integration of renewable energies.
• The calculation of RE2020 kWh/m2/year consumption takes into account several key indicators: the bioclimatic need (Bbio), primary energy consumption (Cep), and non-renewable primary energy consumption (Cep,nr).
• The regulatory thresholds for energy consumption are stricter in RE2020 compared to RT2012, encouraging more efficient constructions.
• The integration of renewable energies, such as photovoltaics, is valued in the consumption calculation, particularly the self-consumed portion, thereby reducing the Cep and Cep,nr indicators.
• Compliance with RE2020 requires the production of two certificates: one during the building permit application and one upon completion of works, issued by authorised professionals.

Understanding RE2020’s requirements for energy consumption

The Environmental Regulation 2020 (RE2020) marks an important step in the construction of more efficient and environmentally friendly buildings. It aims to significantly reduce the energy consumption of new buildings, while integrating a global approach that considers occupant comfort and carbon impact. This new regulation is part of an energy transition and climate change adaptation initiative. The main objective is to construct buildings that consume less and are more comfortable, while preparing for the advent of positive-energy buildings.

The fundamental objectives of RE2020

RE2020 is based on three main pillars:

• Improve the energy performance of buildings: This involves reducing heating, air conditioning, and lighting needs, as well as better management of consumption related to auxiliary systems (ventilation, pumps, etc.).
• Reduce the carbon impact of construction: For the first time, the regulation integrates the life cycle analysis of building materials and components, as well as emissions related to energy production.
• Ensure occupant comfort: RE2020 takes into account thermal comfort in both summer and winter, ensuring that buildings remain pleasant to live in, even during heatwaves or intense cold.

Evolution compared to the previous thermal regulation (RT2012)

RE2020 succeeds RT2012 and brings notable changes. While RT2012 primarily focused on reducing primary energy consumption for heating, air conditioning, domestic hot water, lighting, and auxiliary systems, RE2020 broadens its scope. It now includes consideration of consumption related to everyday equipment (household appliances, electronic devices) and internal movements (lifts, escalators). Furthermore, RE2020 introduces a carbon dimension that was absent from RT2012. Energy demand requirements are also stricter, aiming for a reduction of approximately 30% compared to RT2012 thresholds. For instance, RE2020 pushes towards positive-energy buildings (BEPOS), whereas RT2012 aimed for low-consumption buildings (BBC).

Scope of RE2020

RE2020 applies to new residential building constructions since 1st January 2022. It also extends to office and primary or secondary education buildings since 1st July 2022. Specific provisions are planned for extensions of these buildings, small-surface constructions, temporary constructions, and light leisure dwellings from 2023. The objective is to ensure progressive application adapted to each type of construction. It is important to note that RE2020 only concerns the new build property stock, which represents a small part of the total stock. The major challenges for reducing energy consumption and greenhouse gas emissions therefore also lie in the renovation of existing buildings. The consideration of appliance usage, such as a 5 kW reversible air conditioner, is now integrated into performance calculations, directly influencing the kWh/m²/year [29a6].

RE2020 does not merely set consumption limits. It encourages a global approach that integrates occupant comfort and the environmental impact of building construction and use.

Calculating primary energy consumption under RE2020

To fully understand RE2020, one must examine how primary energy consumption is calculated. This is a central element of the regulation. We are talking here about the energy that must be produced at the source to be able to use the final energy at home. Think of it as the total energy cost, even before electricity or gas reaches your premises.

Definition and importance of primary energy consumption (Cep)

Primary energy consumption, often abbreviated as Cep, represents the total amount of primary energy required to cover all the building’s needs. This includes heating, domestic hot water production, cooling, lighting, and ventilation. RE2020’s objective is to reduce this consumption as much as possible. It is expressed in kilowatt-hours of primary energy per square metre per year (kWhep/m²/year). It is a key indicator for evaluating a dwelling’s overall energy performance. A low value means that the building is well-designed and well-insulated, and that the systems used are efficient. For example, for a 100 m² house, RE2020 sets an electricity consumption ceiling of 2,174 kWh per year, which corresponds to 50 kWh/m²/year with a conversion factor of 2.3 [59d8].

Consideration of different energy uses

RE2020 takes into account several energy uses for the calculation of Cep. It includes the five uses from RT2012: heating, domestic hot water, cooling, lighting, and ventilation. But the new regulation goes further by also including:

• Electricity consumed by lifts and escalators.
• Electricity for lighting and ventilation systems in car parks.
• Electricity for common areas in collective buildings.

This more comprehensive approach provides a more precise view of the building’s actual consumption.

Impact of heating and cooling systems

Heating and cooling systems have a major impact on primary energy consumption. RE2020 encourages the use of efficient and low-energy systems. For example, the electricity to primary energy conversion coefficient has been revised downwards in RE2020 (from 2.58 to 2.3) compared to RT2012. This means that electricity is less penalised in the calculation, which can make electric heating more attractive under this new regulation. It is important to choose the correct nominal power for your equipment, as it is directly linked to energy consumption [8af5].

The calculation of primary energy consumption is an essential step to ensure that the building complies with RE2020 requirements. It takes into account all energy uses and the efficiency of installed systems.

Key energy performance indicators of RE2020

The Environmental Regulation 2020 (RE2020) introduces several indicators to measure and improve the energy and environmental performance of new buildings. These metrics allow for the evaluation of construction quality and its impact on the climate. Understanding these indicators is essential for designing more energy-efficient and comfortable buildings.

The bioclimatic need (Bbio)

The bioclimatic need, or Bbio, represents the amount of energy required for heating, cooling, and lighting a building, taking into account its architectural characteristics and environment. It is calculated by considering elements such as insulation, airtightness, orientation, and the building’s compactness. The objective is to minimise these intrinsic needs through intelligent design, favouring passive solar gains in winter and limiting overheating in summer. A building with a low Bbio will depend less on active heating and air conditioning systems.

Primary energy consumption (Cep)

Primary energy consumption, or Cep, measures the total amount of primary energy required to cover the building’s various uses: heating, domestic hot water, cooling, lighting, and auxiliary systems (such as fans or pumps). Primary energy includes the energy consumed by production and distribution systems. RE2020 sets strict ceilings for this indicator, encouraging the use of efficient equipment and the reduction of energy losses. The objective is to limit the building’s overall energy consumption throughout its use.

Non-renewable primary energy consumption (Cep,nr)

Cep,nr goes further by focusing specifically on the portion of primary energy consumed that comes from non-renewable sources (such as fossil fuels). This indicator aims to reduce dependence on non-renewable resources and encourage the use of renewable energies. By limiting Cep,nr, RE2020 promotes the adoption of more ecological heating and domestic hot water production systems, such as heat pumps or solar thermal systems. The evolution of this indicator’s calculation has notably modified the valuation of electric heating, by taking into account a lower electricity emission factor than before, which is a notable evolution compared to RT2012.

These three indicators form the core of the energy performance evaluation for new buildings under RE2020. They are interdependent and must be jointly optimised to achieve the objectives of energy sobriety and environmental impact reduction.

Integration of renewable energies and self-consumption

RE2020 places particular emphasis on the integration of renewable energies and self-consumption. The idea is to produce a portion of the energy consumed on-site, thereby reducing reliance on grids and the building’s overall environmental impact. This involves, in particular, the installation of systems such as photovoltaic panels, but also finer management of daily energy consumption.

Role of photovoltaic installations in RE2020 calculation

Photovoltaic solar panels play an important role in achieving RE2020 objectives. Their electricity production can be taken into account in the calculation of the building’s primary energy consumption. The objective is to maximise the value of this local and renewable production.

Methods for accounting for self-consumed production

RE2020 distinguishes several ways to value photovoltaic production:

• Total self-consumption: Electricity produced and consumed on-site is valued with a specific coefficient. This means that the energy you produce and use directly in your home is accounted for advantageously in the regulatory calculation.
• Surplus injected into the grid: Electricity produced but not consumed on-site and reinjected into the electricity grid can also be taken into account, often within a certain limit per square metre per year.
• Unvalued production: The portion of production that is neither self-consumed nor injected into the grid (or that exceeds valuation thresholds) is treated differently.

The precise calculation of the self-consumed portion is done by comparing the hourly electricity production of the panels with the building’s electricity consumption over the same period. This annual self-consumption rate (TAC) is then used in the calculations.

Impact on energy performance indicators

The successful integration of renewable energies and self-consumption has a direct and positive impact on the building’s energy performance indicators. By reducing net primary energy consumption, particularly that from non-renewable sources, these installations help to approach the objectives set by RE2020, or even aim for positive-energy building (BEPOS) status. This results in a better overall score during the energy performance evaluation of the dwelling or commercial building.

Regulatory consumption thresholds for new buildings

The Environmental Regulation 2020 (RE2020) sets precise limits for energy consumption in new constructions. These thresholds aim to encourage the construction of more energy-efficient and environmentally friendly buildings. They are calculated in kilowatt-hours per square metre per year (kWh/m²/year) and take primary energy into account.

Consumption ceilings for individual dwellings

For individual houses, RE2020 establishes a primary energy consumption ceiling. This ceiling is set at 12 kWh/m²/year for heating, cooling, and domestic hot water production. This is an ambitious objective that drives advanced bioclimatic design and the use of efficient systems. This threshold represents a notable evolution compared to previous regulations, which were less strict on these specific uses.

Requirements for collective and commercial buildings

Collective residential buildings and commercial buildings (offices, shops, etc.) are also subject to consumption ceilings. Although the exact values may vary slightly depending on the building category and its use, the spirit of RE2020 remains the same: to limit primary energy consumption.

• Collective residential buildings: The threshold is generally aligned with that of individual houses for heating, cooling, and domestic hot water uses, i.e., 12 kWh/m²/year. Additional requirements may apply to common areas.
• Commercial buildings: Thresholds are defined by usage category and may be higher, reflecting different energy needs. For example, an office will not have the same requirements as a restaurant. The objective is always to reduce overall consumption.

Comparison of thresholds with RT2012

RE2020 marks an additional step in energy performance compared to RT2012. While RT2012 primarily focused on the bioclimatic need (Bbio) and primary energy consumption (Cep) without differentiating non-renewable energy, RE2020 introduces a more comprehensive approach.

The table below illustrates the main difference in Cep:

Indicator	RT2012 (max)	RE2020 (max)
Cep (Dwelling)	50 kWh/m²/year	12 kWh/m²/year (Heating, cooling, DHW)

It is important to note that RE2020 also integrates a carbon dimension, which was not the case for RT2012. This new regulation therefore pushes for even greater energy sobriety and better consideration of the environmental impact of materials and systems used. For more details on the requirements, it is advisable to consult the official texts that specify these regulatory thresholds.

RE2020 does not merely set consumption limits. It encourages a global approach to energy performance, integrating summer comfort and carbon impact, in order to construct more sustainable and pleasant buildings.

Factors influencing the calculation of kWh/m²/year in RE2020

The calculation of primary energy consumption, expressed in kWh/m²/year, under RE2020 is influenced by several elements that modulate a building’s energy performance. It is not a simple measurement, but an evaluation based on precise assumptions.

Meteorological and climatic scenarios

RE2020 uses updated climatic data to evaluate energy needs. This data is based on typical years from a period ranging from 2000 to 2018, replacing older references. Furthermore, some meteorological stations have been updated, such as the replacement of La Rochelle by Tours and Nice by Marignane. These adjustments aim to better reflect the actual climatic conditions to which the building will be exposed, directly impacting the necessary heating and cooling calculations.

Occupancy scenarios and user behaviour

Occupancy scenarios have been revised to better correspond to actual inhabitant behaviour. However, it is important to note that these scenarios remain conventions and average profiles. They therefore cannot accurately predict actual consumption, which depends heavily on individual habits. The objective is to provide a representative calculation basis, but individual variability remains a factor.

Importance of building airtightness

Airtightness, measured in m³/(h.m²), is a determining criterion. It represents the amount of air that escapes or enters the building in an uncontrolled manner. Regulatory thresholds vary depending on the type of building: 0.6 for individual houses and 1 for collective dwellings. Increases may apply if works affecting this airtightness are yet to be carried out. Good airtightness limits heat loss and improves comfort, while reducing heating and air conditioning needs. A precise evaluation of this performance is therefore essential for regulatory calculation. Estimating costs for a solar installation, for example, must take these aspects into account for proper system sizing Estimating solar panel costs.

Considering these different factors allows for a more accurate evaluation of the building’s energy performance, approaching real-world usage conditions while maintaining a clear and comparable regulatory framework between projects.

Certificate of conformity to RE2020 requirements

To ensure that your project complies with the Environmental Regulation 2020, two main documents are required, similar to RT 2012. These certificates serve as proof that all rules have been followed.

Documents required during the building permit application

When submitting your building permit application, you will need to provide an initial certificate. This document, generally prepared by the project owner or project manager, confirms that you have carried out a feasibility study regarding energy supplies. It also certifies that you have conducted a life cycle analysis of your building, in accordance with RE2020 requirements. This is a preliminary step that demonstrates the environmental approach is considered from the outset of the project.

Documents required upon completion of works

Once construction is complete, a second document is essential. It is drawn up on your behalf by a qualified professional. This professional may be an architect, an energy performance diagnostician (for individual or semi-detached houses), a control office, or a certification body if your building is certified. This final document is attached to the declaration attesting to the completion and conformity of the works. It confirms that the building, once constructed, complies with all RE2020 requirements, particularly in terms of primary energy consumption and carbon impact. The connection of your photovoltaic installation, for example, must comply with current standards to be validated in this context obtain a certificate.

Role of authorised professionals in certification

Authorised professionals play a key role in validating RE2020 compliance. They guarantee that calculations and realisations correspond to regulatory expectations. Their intervention ensures the objectivity and expertise necessary to certify that a building meets the energy and environmental performance criteria set by RE2020. Without their validation, it is impossible to prove the project’s conformity.

Specific developments for electric heating

Electric heating has always been a subject of discussion in thermal regulations, and RE2020 is no exception. There have been notable adjustments compared to RT2012, particularly concerning how electricity consumption is converted into primary energy. This is an important point to understand to fully grasp the requirements.

Modification of the electricity to primary energy conversion coefficient

In RT2012, the conversion coefficient was 2.58. This meant that for every kilowatt-hour (kWh) of electricity you consumed at home, it was considered that 2.58 kWh of primary energy was needed upstream to produce it. With RE2020, this coefficient has been revised downwards, to 2.3. In other words, 1 kWh of consumed electricity is now equivalent to 2.3 kWh of primary energy. This modification makes electric heating slightly less penalised in energy performance calculations.

Impact on the valuation of electric heating

This evolution of the coefficient has a direct impact on how electric heating is perceived under RE2020. By reducing the penalty associated with electricity, the regulation makes electric heating more competitive compared to other systems, especially when considering the progress made in the energy efficiency of modern electrical appliances. It is always good to inquire about the most efficient radiator types for your home, such as those with inertia, which can help optimise your consumption. You can find useful information on consumption simulations.

Analysis of debates on CO2 emission factors

RE2020 also takes into account carbon impact, and the calculation of CO2 emitted by electricity has been the subject of much discussion. The emission factor adopted for electric heating is 79 g CO2/kWh, which represents a division by 2.3 compared to RT2012. These figures are based on specific calculation methods that attempt to best reflect the reality of electricity production, particularly during winter demand peaks. ADEME has also published notes detailing these different calculation methods. It is important to note that electricity consumption for heating is very sensitive to climatic conditions and can lead to significant power demands on the electricity grid during cold periods. RE2020 seeks to better integrate these realities into its requirements, while promoting more energy-efficient and environmentally friendly solutions. The consumption thresholds are therefore calculated with this new data in mind.

Consideration of carbon impact in RE2020

The Environmental Regulation 2020 (RE2020) is no longer limited to energy performance alone. It now integrates a significant carbon dimension, evaluating the impact of buildings on climate change throughout their life cycle. This approach aims to encourage more sustainable construction practices and reduce the sector’s overall environmental footprint.

Integration of life cycle analysis of materials

One of the major changes introduced by RE2020 is the systematic consideration of the Life Cycle Analysis (LCA) of construction materials. This means that the environmental impact of materials is evaluated from their extraction, manufacturing, transport, to their end-of-life. The objective is to promote the use of low-carbon impact materials, such as those of plant origin or recycled.

• Valuation of bio-based materials: The regulation actively encourages the use of bio-based materials (wood, hemp, straw, or even cellulose wadding). These materials generally have a lower, or even negative, carbon footprint, as they store CO2 during their growth.
• Reduction of the impact of conventional materials: In parallel, RE2020 aims to limit the use of materials whose production is highly greenhouse gas-emitting, such as cement or steel, by setting emission ceilings.
• Environmental data: To carry out these calculations, RE2020 relies on specific databases, such as that of INIES, which list the Environmental Product Profiles (PEP) of materials. This data allows for a precise evaluation of the carbon impact of each component used in construction.

The integration of LCA for materials is a key step towards truly sustainable construction, as it pushes for a rethinking of resource choices from the design stage.

Calculation of the impact on climate change (Icconstruction)

RE2020 introduces a new indicator: the Impact on Climate Change related to construction (Icconstruction). This indicator quantifies greenhouse gas (GHG) emissions over the entire life cycle of the building, focusing on the construction phase. It is expressed in kilograms of CO2 equivalent per square metre per year (kg eq.CO2/m²/year).

The thresholds for this indicator are progressive, with CO2 emission reduction targets for new constructions.

Year	Icconstruction Ceiling (kg eq.CO2/m²/year)
2025	640
2028	560
2031	480

These thresholds aim to encourage professionals to adopt less carbon-intensive construction solutions. The calculation of this indicator is carried out using specific software that integrates environmental data for materials and construction processes. It is important to note that RE2020 projects a significant reduction in carbon emissions, with ambitious targets for the coming years, thereby contributing to the national strategy for combating climate change. For example, it is estimated that the regulation could lead to a saving of 7.9 million tonnes of CO2 by 2031, based on current construction figures. A carbon saving is therefore expected.

Valuation of bio-based materials

RE2020 pays particular attention to the valuation of bio-based materials. These materials, derived from biomass, offer several environmental advantages. They have low embodied energy, meaning they require little energy to be produced and processed. Furthermore, as mentioned previously, they store carbon during their growth, which helps to reduce the building’s overall carbon footprint.

• Ecological advantages: In addition to their low carbon impact, bio-based materials are often renewable and biodegradable, which limits waste production at the end of their life.
• Thermal performance and comfort: Many of these materials also offer excellent thermal and acoustic insulation performance, thus contributing to occupant comfort and reducing heating and air conditioning needs.
• Certification processes: To facilitate their integration, specific certification processes and labels exist for bio-based materials, attesting to their quality and environmental performance. The use of these materials is an effective way to meet RE2020 requirements and to construct healthier and more environmentally friendly buildings. The use of dedicated software allows for the RE2020 calculations to be carried out, taking these specificities into account.

Towards positive-energy buildings (BEPOS)

RE2020 goes further than previous regulations by aiming for an ambitious objective: the positive-energy building (BEPOS). This means that the building must produce more energy than it consumes over a year. This is a major evolution compared to RT 2012, which focused on low consumption (BBC). The transition to BEPOS implies a global reflection on building design and the integration of efficient systems.

Objective of energy production exceeding consumption

The idea behind BEPOS is to create buildings that are no longer mere energy consumers, but become genuine producers. This translates into primary energy consumption (Cep) that must be lower than the building’s renewable energy production. To achieve this objective, RE2020 strongly encourages the use of renewable energies.

• Photovoltaic panels: These are a preferred means of producing electricity. Self-consumption, i.e., the use of electricity produced directly on-site, is particularly valued in the RE2020 calculation.
• Solar thermal systems: These can be used for domestic hot water production or even for heating.
• Efficient heat pumps: Whether aerothermal, geothermal, or hydrothermal, they allow for the recovery of calories present in the air, ground, or water to heat the building and produce hot water.
• Efficient wood-fired boilers: These can also contribute to renewable energy production.

Achieving BEPOS status relies on a synergy between highly efficient insulation, optimised bioclimatic design, and the judicious integration of renewable energy production systems.

Role of equipment and renewable energies

Equipment plays a central role in the transition to BEPOS. It is not just about installing solar panels, but about thinking about the building’s entire energy system in a coherent manner. For example, a well-sized heat pump combined with photovoltaic production can cover a large part of heating and domestic hot water needs, while minimising carbon impact.

The self-consumption of electricity produced by photovoltaic panels is particularly advantageous. Under RE2020, self-consumed electricity benefits from a higher valuation coefficient than that injected into the grid. This encourages the design of buildings where energy production and consumption are as close as possible.

Comparison with the concept of Low Consumption Building (BBC)

The difference between a low consumption building (BBC) and a positive-energy building (BEPOS) is significant. While BBC aims to limit primary energy consumption (for example, a maximum of 50 kWh/m²/year for RT 2012), BEPOS goes further by requiring energy production to exceed consumption. The BBC label was one step, BEPOS is another, more demanding one.

In summary, the transition to BEPOS represents a paradigm shift: we are no longer just seeking to reduce consumption, but to produce energy, thus transforming the building from a mere consumer into a positive actor in the energy landscape.

Imagine a future where buildings produce more energy than they consume! This is the idea behind positive-energy buildings, or BEPOS. It’s a smart way to build that helps our planet and can save you money. Want to learn more about how we can create these amazing homes and offices? Visit our website today to discover the possibilities!

Conclusion: Mastering RE2020 for more efficient buildings

Ultimately, understanding and applying RE2020 means ensuring that our constructions meet current requirements for energy performance and environmental impact. It is clear that the regulation has evolved compared to RT2012, by integrating new uses and focusing more on the life cycle of materials and carbon. Calculating kWh/m²/year is therefore not just an administrative formality; it is a key step in designing more energy-efficient, healthier, and more pleasant buildings. This requires a little attention to detail, but it is well worth the effort for the future of our environment and our daily comfort.

Frequently Asked Questions

What is RE2020 and why is it important?

RE2020 is the new rule for constructing more ecological homes in France. It replaces an old rule called RT2012. Its main goal is to ensure that homes consume less energy, especially polluting energies, and that they are more comfortable for those who live in them. It also considers the impact of construction on the planet, by looking at the materials used.

What is the main difference between RE2020 and RT2012?

The big difference is that RE2020 goes further than RT2012. Previously, the focus was mainly on energy consumption for heating, cooling, hot water, etc. Now, with RE2020, we also look at the impact of manufacturing materials and even the energy consumed by everyday appliances like fridges or TVs. It’s a more comprehensive vision for constructing more environmentally friendly buildings.

How does RE2020 calculate energy consumption?

To calculate consumption, RE2020 uses several important points. There’s the ‘bioclimatic need’ (Bbio), which measures the need for heating, cooling, and light based on how the building is designed (orientation, insulation…). Then, there’s ‘primary energy consumption’ (Cep), which takes into account all the energy used for different purposes (heating, hot water, etc.), converting each type of energy (electricity, gas) into a common unit. Finally, there’s ‘non-renewable primary energy consumption’ (Cep,nr), which focuses on energy from non-renewable sources, such as oil or gas.

Do solar panels help meet RE2020?

Yes, solar panels can help! RE2020 takes into account the electricity you produce yourself with your panels (self-consumption). This production reduces the amount of energy you need to buy, which improves your energy score. However, installing solar panels slightly increases the carbon impact related to the construction of the building itself, as these panels need to be manufactured.

What are the consumption limit figures in RE2020?

RE2020 sets limits so that buildings do not consume too much. For example, for an individual house, total energy consumption must be much lower than before, and the carbon impact related to consumption must be limited. There are also targets for heating needs, which must be very low. These figures are stricter than in RT2012 to encourage even more efficient buildings.

What is the ‘bioclimatic need’ (Bbio)?

The ‘bioclimatic need’ is somewhat like a building’s natural requirement to be comfortable without consuming too much energy. It takes into account how the building is oriented towards the sun, how it is insulated, and how it is protected from the wind. Good bioclimatic design helps reduce the need for heating in winter and cooling in summer, simply by using nature.

How does RE2020 take electric heating into account?

RE2020 has changed the way primary energy for electricity is calculated. Previously, 1 kWh of consumed electricity was considered to come from 2.58 kWh of energy at the source. Now, it’s 2.3 kWh. This makes electric heating slightly more ‘advantageous’ in calculations compared to the old rule, as it is considered more efficient to produce. That said, the objective remains to reduce overall consumption.

What is a positive-energy building (BEPOS)?

A positive-energy building, or BEPOS, is the highest level in terms of energy performance. This means that the building produces more energy than it consumes over a year. To achieve this, highly efficient insulation, excellent airtightness, and the use of renewable energy sources, such as solar panels, are required. This is the objective towards which RE2020 is striving.