Gröningen – September 07, 2026 -- The Deutsche Bundesstiftung Umwelt (DBU) is funding a roughly €300,000 renovation of the 17th-century Rittergut Edelhof manor in Gröningen, Saxony-Anhalt, installing one of Germany's first water-ice thermal storage systems in a historic building. The project, underway since late last year, is scheduled for completion by April 2028 and aims to return residential use to a building vacant since the 1990s.
Water-ice storage cuts heating energy demand by up to 50 percent
A heat pump extracts energy from water until it freezes, supplying heat during sub-zero temperatures without large battery storage. Scientific project lead Prof. Dr. Harald Garrecht said this system works alongside a roof-integrated heat-recovery unit that draws warmth from the environment above freezing, together cutting required heating energy by up to 50 percent.
New clay-aerogel insulation plaster reduces heat loss at just 3-4 centimeters thickness
A newly developed insulation render combining clay and aerogels reduces heat loss by up to 50 percent despite its thin application, according to Garrecht. Electricity will come from photovoltaic roof tiles designed to visually match traditional Saxony-Anhalt roofing tiles known as Linkskremper, preserving the building's historic appearance while generating power. Garrecht cited similar systems previously used at Essen's Margarethenhöhe garden city and Hamburg's Speicherstadt.
DBU frames the retrofit as a blueprint for historic buildings nationwide
DBU Secretary General Alexander Bonde called the project a model for making city centers livable through climate-neutral energy generation, modern insulation and intelligent storage systems in historically valuable buildings. Garrecht said the renovation will produce a guidance document for sustainable retrofitting of cultural heritage structures, particularly in small towns, applicable across Saxony-Anhalt and Germany. The work involves the Deutsches Fachwerkzentrum Quedlinburg and several small and medium-sized enterprises.
DBU subsidiary manages over 11,100 hectares of protected land in Saxony-Anhalt
Separately, DBU Naturerbe, the foundation's nonprofit subsidiary, oversees ten National Natural Heritage sites in Saxony-Anhalt totaling roughly 11,100 hectares, including the Ringfurther Elbauen wetlands and the Oranienbaum Heath in Dessau-Roßlau district. DBU referent Constanze Fuhrmann said resource-efficient retrofits like the Edelhof project avoid the loss of valuable building fabric while cutting climate-damaging emissions compared with new construction.