GEG certification
The requirements of the European directive on the overall energy performance of buildings have been implemented in Germany since 2021 via the Buildings Energy Act (GEG), which is being replaced by the Buildings Modernization Act (GModG) — passed on July 10, 2026 by the Bundestag and Bundesrat. The GEG, and in future the GModG, thus forms the minimum legal framework to be observed for new builds as well as measures on existing buildings.
The certification procedure checks compliance with the maximum value for annual primary energy demand as well as the requirements for the thermal insulation quality of the building envelope. Annual primary energy demand covers the needs for heating, hot water, air conditioning, and lighting, taking into account the additional energy required for extraction, conversion, and distribution — i.e., the upstream process chains outside the building. The key standards remain DIN V 18599 as well as the standard pair DIN 4108-6 & 4701-10. With the GModG, the primary energy factors of individual energy sources as well as the underlying reference-building tables will change in particular.
We prepare the GEG certification for you in line with the currently applicable version — currently the GEG, and in future the GModG — as well as any further requirements that may arise, for example, from funding sought for energy-efficient construction. In addition, we work with the planning team to optimize the energy balance for the entire building.
As part of the GEG certification, it must also be demonstrated that the summer thermal protection of occupied rooms meets the requirements of DIN 4108. We calculate the necessary sun-protection measures for this.
EWärmeG certification
The Renewable Heat Act (EWärmeG) is a state law for Baden-Württemberg. Since 2010, it has required owners of existing residential buildings to use renewable energy as soon as they replace their heating system.
The revised version of the law has applied since July 1, 2015. The EWärmeG 2015 applies to buildings built before January 1, 2009, where the heating system is replaced from July 2015 onward. New buildings are also subject to an obligation to use renewable energy; here, the federal Renewable Energies Heat Act has applied since January 1, 2009.
From July 1, 2015, when a heating system is replaced in existing residential and non-residential buildings, 15% of the heat must be covered by renewable energy, or equivalent substitute measures must be demonstrated. This is where we come in. Ideally, you involve us already during the planning phase of the heating system — there is generally high funding potential here, with subsidy rates of up to 55%.
Energy renovation measures already carried out on your building may, under certain circumstances, help meet the requirements.
