In this research project the indoor air quality in energy-efficient buildings has been investigated with regard to odours and volatile organic compounds. The original aim of the study was to investigate the indoor air quality of energy-efficient retrofitted buildings using the example of the German Environment Agency’s (Umweltbundesamt, UBA) Bismarckplatz office building in Berlin. Due to the postponement of the remediation works for the Bismarckplatz office building, the project specification was changed in agreement with UBA and the Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety (BMUB). The new building “UBA Haus 2019” and one floor in an office building to be renovated were included in the new project specification. In addition, further olfactory analyses of various wall and floor assemblies installed in test rooms of the eco-INSTITUT in Cologne were conducted. Around 60 single products and combinations of materials have been tested in emission chambers. These products were also placed in the new or refurbished buildings or evaluated in real test rooms.