Energiesprong is a concept that originated in the Netherlands and concerns the refurbishment of apartment buildings with prefabricated elements to achieve the NetZero energy standard. The biggest German initiative of its kind has just got underway in Bavaria. Some 6,000 residential units owned by Gewobau Erlangen will be retrofitted with photovoltaic (PV) solar systems on the roofs and façades, together with energy-efficient technology.

The vision is to make the buildings energy self-sufficient, with heating, hot water and electricity supplied regeneratively, greatly reducing energy costs for the tenants. "From a housing industry perspective, not only the necessity of climate protection measures is of great importance, but also the obligation to keep the building stock up-to-date and attractive for residents,” says Gernot Küchler, managing director of Gewobau, in a press release issued by the German Energy Agency (dena).

“The size of the refurbishment project sends important signals for the innovative handling of building stock and the success of the heat transition...It also sends a signal to construction companies and manufacturers to develop scalable, serial solutions even more quickly," says Andreas Kuhlmann, chairman of dena's management board.

dena estimates there are 500,000 small to medium-sized apartment buildings in Germany built between 1950 and 1980 that are suitable for conversion. The agency has developed a “building block kit” to enable cost-effective NetZero refurbishments to be rolled out quickly and is looking at expanding Energiesprong to other building types this year. The project will cost a total of 400 million euros. It is financed by subsidies from the federal government and the Free State of Bavaria, with equity substitute funds from the European Investment Bank.