Excess heat from industrial processes can be utilized in district heating networks, thereby reducing the primary energy demand and possibly the CO2 emissions for generating district heating. Numerous studies found a substantial potential of industrial excess heat, but have not systematically considered future changes in the energy system that will affect its utilization potential. Industrial production is set to transform to low-carbon processes and district heating needs to be generated without the use of fossil fuels. We quantify industrial excess heat using spatial matching for the EU-27, and considering the impact of the transformation to a climate-neutral energy system. The first step identifies excess heat potentials from energy-intensive industries as point sources, and considers process changes. The subsequent step spatially matches these excess heat potentials to district heating areas using a GIS-based approach. The results show that the amount of available excess heat will decrease significantly due to industry transformation. At the same time, the utilization could be increased due to lower district heating system temperatures and expanding district heating areas, resulting in 3-36 TWh per year. At local level, industrial excess heat can make a significant contribution to the supply of district heating in the future, but the major share will need to come from renewables.