The future population distribution informs decisions on investment in district heating. Across Europe, demographic change has been associated with structural changes of the past. Trends towards urban or rural migration, urban sprawl or the depopulation of city centers will continue. Using gridded population data since 1990, past development is mapped using spatial disaggregation to grid cells by intensity of urban development. An empirical method proposed captures increment of population in each grid cell and relates it to the focal statistics of the cell neighbourhood. A positive population trend in populated cells leads to a future population increase and a spill over into new development areas, while a negative trend leads to lower future population. New areas are modelled based on the principles of proximity and similarity using neighbourhood trends and land cover suitability, adjusted to national and regional population trends. The result is a set of future 1-hectare population grids, which have been used to model the distribution of future heat demands. The distribution of heat demand densities, the zoning of heat supply, and the potential for individual heat pumps have been modelled. Results show that reductions of heat demands and demographic developments leave a window of opportunities to develop heating infrastructures with known technology in the present decade, after which 4th Generation District Heat technology is required to decarbonise the heating sector.