5.1 Building Energy Act

In Germany, the requirements for the energy quality of new buildings and the modernisation of old buildings have been anchored in the Energy Efficiency of Buildings Act (GEG) since 1.11.2020. The contents of the Energy Saving Ordinance (EnEV), the Energy Saving Act (EnergieeinsparG) and the Renewable Energies Heat Act (EEWärmeG) have been combined in this act. The total energy requirement for heating, hot water preparation, ventilation and cooling, and in non-residential buildings for built-in lighting too, may not exceed the maximum value defined in the GEG. The Lowest Energy Building Standard has applied for new, non-residential buildings since 2021, having come into force for public buildings in 2019. The GEG defines DIN V 18599 as the calculation procedure for the energy assessment (see section 5.2).

5.2 DIN V 18599

In the German DIN V 18599 standard‚ energy-related evaluation of buildings calculation of used, end and primary energy requirements for heating, cooling, ventilation, hot water and lighting‘, the energy requirements for lighting is considered as a whole together with the complete energy efficiency of buildings. The buildings are zoned according to energy specifications and each zone is assigned a utilisation profile. For calculation methods, the standard defines both simple tables and detailed specialist planning.


With the introduction of the energy services act (EDL-G) energy audits in accordance with EN 16247-1 are mandatory for all commercial enterprises as of December 2015. Only small and medium-sized enterprises (SME) as well as companies with their own energy management system in accordance with ISO 50001 are exempt from this. At least 90 % of the total energy consumption is determined as part of the audit and possible potential for energy savings are highlighted. Repeat audits are required by law 4 years after the previous audit at the latest.


In order to meet increased needs for energy efficiency, lighting installations should be optimised according to energy-related factors. This applies both to the refurbishment of old systems and lighting systems to be newly installed.

The components to be analysed are:

  • Light source (in particular luminous flux)
  • Control gear (connected load, start behaviour, standby losses)
  • Lighting technology of the luminaire (light output ratio and light distribution)
  • Lighting management (lighting control, presence detection)
  • Maintenance (long service life, ease of maintenance)


When the EU regulations 2019/2020 (ecodesign) and 2019/2015 (energy labelling) came into force on 01.09.2021, the energy efficiency classes and energy labels of light sources were restructured. For this purpose, a new calculation algorithm has been introduced, and the efficiency classes have been defined in levels from A (highest efficiency) to G (lowest efficiency). During a transition period, old labels are still valid until 01.03.2023.
There is no longer a labelling obligation for luminaires with the new regulations, but the energy efficiency class of the installed light source must be stated in the installation or operating instructions of the luminaire. This information obligation takes effect on 01.03.2022.

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