HRE4 aims to develop low-carbon heating and cooling strategies, called Heat Roadmaps, by quantifying and implementing changes at the national level for 14 EU Member States. HRE4 is funded by the European Union's Horizon 2020 research and innovation programme under grant agreement No. 695989, and addresses topic EE-14-2015 "Removing market barriers to the uptake of efficient heating and cooling solutions" of the Energy-efficiency Call. Our team contributes with a further development of Peta, including detailed mapping of demands and supply, extensive data input for energy systems analysis and an online mapping platform.