The energy transition is progressing and the German Building Energy Act (GEG) is a decisive step towards accelerating the switch to climate-friendly heating systems. Germany faces the challenge of replacing around three quarters of heating systems that currently still run on gas or oil with sustainable alternatives. The GEG, which has been in force since January 2024, sets clear targets for achieving climate neutrality by 2045 and reducing dependence on fossil fuels.
The objectives of the GEG and its scope of application
The GEG applies equally to residential and non-residential buildings. The central objective is to increase the use of renewable energies, particularly for heating new buildings. From January 2024, only heating systems that use at least 65 per cent renewable energy may be installed in new buildings within new development areas. This step should not only reduce CO2 emissions, but also significantly reduce dependence on fossil fuels.
There are longer transitional periods for existing buildings and new buildings in gaps between buildings. These are intended to enable better coordination of the investment decision with local heating planning. In large cities (>100,000 inhabitants), the installation of heating systems with at least 65% renewable energy will become mandatory after 30 June 2026 at the latest, and in smaller cities (<100,000 inhabitants) after 30 June 2028.
Transition periods, exceptions and exemptions
The strict requirements of the GEG apply to the installation of new heating systems. However, existing heating systems may continue to be operated and repaired. Pragmatic solutions are possible during the transition period until mid-2026/2028, particularly when installing gas or oil heating systems. Mandatory consultation prior to installation is planned in order to take local heating plans and rising CO2 prices into account. From 01.01.20209 , 15% renewable energies must then be verified, from 01.01.2035 then 30% and from 01.01.2040 60% if an oil/gas heating system was put into operation after 01.01.2024.
Building owners can be exempted from the obligations of the GEG in cases of hardship. Financial difficulties, need for care or other personal circumstances can justify exemptions.
Focus on open-technology solutions
The new regulations in the GEG are deliberately designed to be technology-neutral. This gives building owners the freedom to choose from various general fulfilment options in order to meet the requirements. These options allow flexible adaptation to different buildings and individual needs:
- Connection to a district or building heating network: This effectively uses and combines various renewable heat sources and waste heat (e.g. from industrial plants or data centres).
- Installation of an electric heat pump: This primarily utilises free and renewable environmental heat from the ground, air or water.
- Direct electric heating: Particularly suitable for well-insulated buildings with low heating requirements, including infrared heaters.
- Heat pump or solar thermal hybrid heating: A combination with fossil fuels or biomass for peak loads to meet the 65 per cent renewable energy target.
- Solar thermal or biomass heating: Full or partial use of renewable energy.
Gas heating with renewable gases: This must use at least 65 per cent biomass, sustainable biomethane or biogenic liquid gas or green or blue hydrogen.
Conclusion: A sustainable future through customised solutions
The GEG marks a milestone on the road to climate neutrality and reduces dependence on fossil fuels. The open-technology solutions not only offer flexibility, but also allow customisation to different buildings and conditions. Building owners should find out about the new regulations at an early stage and retrofit their heating systems accordingly in order to make a sustainable contribution to climate protection and benefit from the various funding opportunities.
