Energy efficient retrofit of a prefabricated concrete panel building (Plattenbau) in Berlin by applying an aerogel based rendering to its façades

The first application of a commercially available aerogel based rendering to the external façades of a 30-m-high building made of prefabricated concrete panels (Plattenbau) for energy efficient retrofit has been reported. Hygro-thermal simulations of the total water content for different retrofit variations and wall orientations have been carried out to find the appropriate rendering finish in order to avoid moisture accumulations. In order to get independence from inaccurate assumptions on the primary status of the building the thermal performance before and after the retrofit measures has been determined. This has been carried out by means of infrared thermography and two methods for in-situ measurement of the U-value. For comparison a conventional perlite-based insulating rendering was also applied to a similar neighbouring building and investigated. The results have been discussed with respect to preliminary assumptions and theoretical calculations. Special technical measures for the application of this novel rendering to high rise buildings have also been addressed.