The energy-efficient refurbishment of a listed Wilhelminian-era building with a total area of approximately 4,000 m² sets new standards in improving the energy efficiency of "worst-performing buildings" (WPBs). Measures such as replacing all windows and display windows, insulating the roof and basement ceiling, and installing a modern photovoltaic system and energy-efficient heating and ventilation systems have enabled a reduction in final energy consumption of approximately 65 percent. This has been reduced from nearly 1.2 million kWh per year to just approximately 400,000 kWh annually. The energy savings are substantial.
CO₂ emissions are reduced by an impressive 53%, representing an annual reduction of approximately 130,000 kg of CO₂. Through the implementation of these comprehensive measures and the successful collaboration with the Monument Protection Authority, the building has been moved out of the "Worst Performing Buildings" (WPB) category and achieved energy efficiency class D. Incidentally, a WPB is a building that, due to the level of energy-efficient refurbishment of its building components, is among the 25% of the German building stock that is among the worst performing in terms of energy efficiency (newer energy certificates require class H).
The energy-efficient refurbishment of this historic building is a showcase project for the compatibility of historic preservation and climate protection. It not only saves energy and emissions, but also reduces long-term operating costs and increases the value of the property.
