While a large number of technical solutions for a more efficient and climate-friendly supply of electricity have been established over the past 20 years, the topic of heat has not been considered to the same extent. In 2017, more than one third of the electricity demand in Germany was covered by renewable energies, but only 13% of the heating demand was met by renewable sources. At 1,300 TWh/a, the supply demand for heating is three times higher than that of electricity. For this reason, the project “Wärme in der EUREGIO – fokussieren und modernisieren” (WiEfm) (Engl. Heat in the EUREGIO – focusing and modernising) supported under INTERREG VA, is dedicated to the topic of sustainable heat supply and examines the fundamentals of the heating market in the EUREGIO project area (rural Münsterland and the Dutch regions Overijssel and Gelderland). This research and development project also looks into savings and energy efficiency, as well as provides technical solutions. The overall aim is to design concrete plans for the efficient generation, distribution and use of heat in order to make the topic tangible and relevant for industry, municipalities and planners.