© fotolia.de/Johannes Spreter

Climate Protection vs. Economic Viability

Steinbeis team publishes report on the energy-efficiency of commercial real estate

Combating climate change is an enormous societal challenge and one of the most pressing tasks on the political agenda – especially with regard to the real estate sector. In Germany, political measures such as the country’s 2050 Climate Protection Plan (Klimaschutzplan 2050) and amendments to energy conservation laws aim to make both new and old buildings more eco-friendly. In light of this, the German Property Foundation (ZIA) commissioned the Steinbeis Transfer Center for Energy, Building and Solar Engineering in Stuttgart to prepare an expert report on economic viability.

The report focuses on the energy efficiency of commercial real estate and analyzes the effects of a possible tightening of the German Energy Saving Ordinance (EnEV), Renewable Energy Heat Act (EEWärmeG) and current environmental policies.

Since the EnEV came into force in 2016, buildings’ energy standards have been subject to stricter requirements. The EnEV regulation calculates and assesses the specific construction requirements of the building envelope for different forms of energy supply for three types of building – office buildings, hotels, and shopping malls – based on a representative building of each type. It takes the additional stipulations of the EEWärmeG into account and forms the basis for evaluating primary energy consumption and carbon emissions.

In their report, Prof. Dr.-Ing. Manfred Norbert Fisch – director of the Steinbeis Transfer Center for Energy, Building and Solar Engineering – and his team conclude that merely further tightening the EnEV in the context of the EEWärmeG for commercial buildings is not enough to achieve the politically desired environmental targets. Taking a comprehensive approach that also considers user-specific electricity demand instead of just the EnEV calculation makes this finding even clearer.

In the view of the Steinbeis experts, the targets that the German government aims to meet as part of the energy transition would be more readily achieved through operational optimizations, efficiency enhancements, and greater use of renewable energy in public heating networks and power grids.

The study conducted by the Steinbeis team makes several key findings. It also takes the view that the evaluation criteria of primary energy and specific heat transmission loss (HT’) are barely understood in practice. The method of using a reference building (EnEV 2016) for energy evaluations of a commercial building design is also not practicable.

  • The view of the Steinbeis team is that if the EnEV 2016 were tightened further, heat supply would no longer be possible with all energy sources or would place excessive demands on the thermal quality of the building envelope. As such, this would not be economical or adaptable to new technologies.
  • Additional stricter regulations governing the thermal quality of the building envelope are not expedient.
  • The use of photovoltaics to achieve the targets specified by the EnEV and EEWärmeG is highly relevant in terms of economic viability and saves fossil fuels.
  • Medium-term carbon targets in the real estate sector require a higher proportion of “green energy and gas,” especially when user-specific electricity demand is considered.

As well as these main results, the report by the Steinbeis team also includes a forecast and a series of suggestions. These include simplifying and improving existing laws and regulations as well as introducing a carbon label for buildings. Building performance should be examined while the building is in use, and financial incentives should be based on the actual carbon savings achieved.


Prof. Dr.-Ing. Manfred Norbert Fisch, Tobias Nusser
Steinbeis Transfer Center Energy, Building and Solar Engineering (Stuttgart)