Efficiency in the heat sector and the built environment can be achieved by building retrofits, the replacement of buildings, and the development of district heating as a means of structural energy efficiency. Hereby, excess heat and low-grade renewable heat sources can be integrated in the heat sector. The present report describes the future heat sector of Europe from end-use via infrastructure to heat sources. Future heat demands on national level have been modelled by sEEnergies project partners. In the present work, these demands are being distributed to future urban areas. Population forecasts have been combined with local empirical data to new 100m resolution population grids. They form the basis for the calculation of heat demands for the years 2030 and 2050 on the same geographical level. Potential areas, where district heating could be developed, have been zoned as prospective supply districts (PSDs) and basic statistics of heat demand have been calculated. Then, based on empirical district heating network data from existing district heating networks in Denmark, a new investment cost model for distribution and service pipes has been developed. Based on previous work in the Heat Roadmap Europe research project, the cost model has been improved with a better understanding of the concept of effective width. With the integration of country-specific construction cost data this results in an improved district heat distribution capital cost model for all Member States of the European Union plus the United Kingdom. The spatially explicit combination of district heat potentials and costs results in cost-supply curves for all countries as the basis for the assessment of the economic potential of future district heating. Finally, available excess heat sources from industry, waste incineration, wastewater treatment plants, and current powerplant locations are being allocated to prospective supply districts. Renewable heat potentials, including deep geothermal heat, solar thermal heat, and residual, local biomass, have also been assigned to these prospective heat supply areas. The results of the present work have been published as a web map.