Achieving the 1.5 °C climate target requires, among others, a sustainable transformation of the heat supply. We downscale different European decarbonization scenarios of the heating sector to the Austrian municipal level, using tailor-made downscaling techniques accounting for infrastructure requirements of renewable heat sources and the topology of centralized heat networks. We demonstrate that allocating district heating networks as part of the downscaling from national results to a local resolution is crucial for a cost-effective and efficient decarbonized heat supply in Austria in 2050. We identify potential for eight different districts with centralized heating networks, supplying heat demand between 0.6 and 12 TWh. Nevertheless, seven of these networks do not reach the heat density required for economic and technical efficiency from today’s techno-economic perspective and industry benchmarks. We conclude that the decarbonization leads to centralized heat networks with lower heat densities. Keywords: Centralized heat networks, heat density, district heating, 1.5°C climate target, downscaling, 2050