April 2024 Blog

Zero-emission buildings by 2050: New European requirements for the energy efficiency of buildings

From 2040, there are to be no more fossil fuel boilers in the EU, a solar obligation will be gradually introduced and the ‘zero-emission building’ is to become the new efficiency standard by 2050.

Objectives of the Buildings Directive

On 12 April, the Council of the European Union adopted the new version of the Energy Performance of Buildings Directive (‘Buildings Directive’). Parliament had already approved the draft in March. The directive will soon be published in the Official Journal of the EU. The Buildings Directive 2010/31/EU was adopted in 2010 and will be fundamentally revised with the new version.

As part of the Green Deal, the 27 EU Member States have agreed that the EU should be climate-neutral by 2050. In addition, the EU's greenhouse gas emissions are to be reduced by 55% by 2030 compared to 1990 levels. In the EU, buildings account for 36% of energy-related greenhouse gas emissions and 40% of final energy consumption. The decarbonisation of the real estate sector is therefore considered essential in order to achieve the climate targets. This is to be achieved through the construction of more efficient new buildings, a higher renovation rate for existing buildings and a drastic reduction in primary energy consumption. Furthermore, the Member States are to introduce a solar obligation for buildings.

Once published in the Official Journal of the EU, the directive will come into force immediately. Member States will then have two years to transpose the provisions into national law. The effects of the directive can only be concretised once it has been transposed into national law. It is therefore essential to keep an eye on the transposition and the requirements of the Buildings Directive should already be taken into account now, particularly for project developments and refurbishments.

Individual provisions of the Buildings Directive

National building renovation plans (Article 3 of the Buildings Directive)

In order to achieve the desired increase in efficiency in the building sector, the member states are to draw up national building renovation plans. The building renovation plans are the schedule according to which existing buildings are to be converted into highly efficient ‘zero-emission buildings’ and thus achieve the end of fossil-fuelled boilers by 2040. A ‘zero-emission building’ is a building with a very high energy performance that requires no energy or a very low amount of energy, produces no CO2 emissions from fossil fuels on site and produces no or a very low amount of operational greenhouse gas emissions (Art. 2 No. 2 Buildings Directive).

From 2045, boilers powered by fossil fuels will be banned in Germany under the Building Energy Act (GEG) - also known as the ‘Heizungsgesetz’ - which came into force on 1 January 2024.

Standards for buildings and minimum energy performance requirements (Article 2 No. 2, 3; 7 - 9; 19 of the Buildings Directive)

Energy performance certificates

Until now, there have been considerable differences in the energy efficiency classes of the individual Member States. As a result of the requirements of the Buildings Directive, the Member States now have to introduce a system for drawing up energy performance certificates for buildings in compliance with European requirements. An energy performance certificate should contain the following information, among others

  • the energy performance of the building expressed by a numerical indicator of primary energy consumption in kWh/(m²-a) (kilowatt hours per square metre per year),
  • minimum requirements and targets for energy performance and
  • requirements for zero-emission buildings and nearly zero-energy buildings.

The use of a scale of letters A to G according to the Building Directive is mandatory for energy certificates throughout Europe. Letter A corresponds to ‘zero-emission buildings’ and letter G to buildings with the worst energy performance in the national building stock at the time the scale is introduced.

New buildings

The ‘zero-emission buildings’ standard will be mandatory for certain building types at different times.

  • From 1 January 2028 for new public buildings,
  • for all new buildings from 1 January 2030 and
  • as well as ‘deep renovation’ from 1 January 2030.

According to Art. 2 No. 20 of the Buildings Directive, a ‘deep renovation’ is the conversion of a building or part of a building into a low or zero-emission building in accordance with the ‘energy efficiency first’ principle and focussing on the main building components. The ‘energy efficiency first’ principle is a European guiding principle that takes into account the overall efficiency of the integrated energy system, security of supply and cost-effectiveness, while achieving the most efficient solutions for climate neutrality in order to realise efficiency gains in both primary and final energy consumption. 

Before certain building types are required to meet the ‘zero-emission building’ standard, they must have achieved the ‘nearly zero-energy building’ standard. A ‘nearly zero-energy building’ is a building with a very high overall energy efficiency and in which the almost zero or very low energy demand is covered to a very significant extent by energy from renewable sources (Art. 2 No. 3 of the Buildings Directive). Renewable sources also include energy that is generated on site or in the neighbourhood.

The mandatory efficiency standards in Germany (KfW 55) are regulated in §§ 15 (residential buildings) and 18 (non-residential buildings) GEG. The annual primary energy requirement for the KfW 55 standard must be 45% lower than that of a building that fulfils the requirements of the GEG.

Existing buildings

The directive also contains new and stricter requirements for existing buildings. The Member States must set minimum requirements for overall energy efficiency (maximum energy consumption). They must also take the necessary measures to ensure that the total energy consumption of all non-residential buildings by 1 January 2030 is lower than 16% of buildings with the worst energy efficiency (energy performance class G) compared to 1 January 2020. By 1 January 2033, this total energy consumption should already be lower than 26% of buildings with energy performance class G. Compliance with these thresholds (16% and 26% respectively) is to be verified by the Member States on the basis of the energy performance certificates.

In contrast to the regulation for non-residential buildings, residential buildings are not to be assessed on a building-by-building basis. The Member States are to reduce the average primary energy consumption of the residential building stock. The average primary energy consumption in this sector is to be reduced by at least 16% by 2030 and by at least 20-22% by 2035.

To ensure that buildings with poor energy efficiency are also remodelled as a result of the regulation, there is a restriction in accordance with Article 9 subparagraph 2 of the Buildings Directive. According to this, Member States should ensure that at least 55% of the reduction in average primary energy consumption is achieved by renovating 43% of residential buildings with the poorest energy performance.

Solar obligation (Article 10 of the Buildings Directive)

Another important provision of the amendment is the solar obligation. New buildings are to be designed in such a way that the generation of solar energy is possible in the future. In future, solar energy systems must be installed on buildings if this is technically possible and economically and functionally feasible.

The solar obligation is to apply to all new public buildings and new non-residential buildings with a usable floor area (defined in Art. 2 No. 20 of the Buildings Directive as the floor area of a building) of more than 250 square metres by the end of 2026 at the latest.

For existing public buildings, the deadline is linked to the size of the usable floor area. The solar obligation applies to areas with a usable floor area of more than 2000 m² by 31 December 2027 at the latest, with a usable floor area of more than 750 m² by 31 December 2028 at the latest and with a usable floor area of more than 250 m² by 31 December 2030 at the latest. For existing non-residential buildings with a usable floor area of more than 500 m² that undergo a major renovation or a measure that requires official approval for building renovations, work on the roof or the installation of technical building equipment, the solar obligation applies by the end of 2027 at the latest.

In Germany, solar energy is already mandatory in certain federal states. The solar obligation applies in Lower Saxony (§ 32a Nds-BauO), North Rhine-Westphalia (§ 8 paragraph NRWBauO), Baden-Württemberg (§§ 8a, 8b KSB BW), Hamburg (§ 16 HmbKliSchG), Berlin (§ 3 Solar Act Berlin), Hesse (§ 9a HEG), Bavaria (Art. 44a BayBO), Rhineland-Palatinate (§ 4 LSolarG), Schleswig-Holstein (§§ 10, 11 EWKG), Brandenburg (§ 32a BbgBauO) and from 2025 also in Bremen (§ 2 BremSolarG).


The European Union has set itself the goal of reducing energy consumption and utilising energy from renewable sources in the building sector in order to reduce greenhouse gas emissions. The revised Buildings Directive further tightens the requirements for buildings in this respect. The obligation for Member States to draw up national building renovation plans paves the way for the decarbonisation of the real estate sector. The German GEG needs to be amended again, as the European directive has set the end date for fossil-fuelled boilers at 2040. In Germany, the operation of boilers that run on fossil fuels will be banned from 1 January 2045. In addition, the overall energy efficiency of new buildings is to be improved through the introduction of the ‘zero-emission building’ standard and the reduction of average primary energy consumption in existing buildings. The gradual introduction of a solar obligation for certain types of buildings will force the increased use of renewable energies. Germany has already anticipated this obligation by making solar energy mandatory in most federal states. The Buildings Directive generally forces the Member States to enact effective, proportionate and dissuasive sanction regulations that take effect in the event of a breach of the directive. Germany has two years from the date of publication in the Official Journal to implement the new regulations.

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