A study by Prof. Manfred Norbert Fisch (Steinbeis Innovation Center SIZ energieplus) and Prof. Kunibert Lennerts (Karlsruhe Institute of Technology, KIT), conducted on behalf of the German Property Federation (ZIA), the umbrella organization for the real estate industry, shows that insulation exceeding the requirements of the current Building Energy Act results in only minor and purely theoretical savings in heating energy consumption.
 
At the same time, the additional use of resources leads to increased CO₂ emissions. The study therefore recommends refraining from further tightening the requirements for building envelopes in new construction. In order to significantly reduce greenhouse gas emissions in the building sector by 2030, the study identifies measures that are particularly quick to implement and effective. These include optimizing building operations, installing solar panels on roofs to generate electricity, expanding and utilizing district heating networks, and increasing the use of heat pumps.
 
ZIA study
ZIA Extended Executive Summary
 
The results of the study also attracted attention beyond the specialist public and were featured in the 08/2022 issue of Der Spiegel, among others: https://www.spiegel.de/panorama/gesellschaft/immobilien-warum-der-geplante-bauboom-den-klimaschutz-gefaehrdet-a-c1aaa258-b8b9-44ae-bcd8-6894cd2ee621