Horizon Cities Mission: Low-Temperature Building Heating

Demonstrating, at TRL 7-8, the switch from fossil-fuel and high-temperature heating to low-temperature district heating and heat-pump-based heating in existing multi-apartment buildings. A proposal covers at least two of four approaches: district-level system design and digital controls for low-temperature operation; heat-pump building retrofits capped at a 50°C supply temperature, demonstrated in at least four apartment buildings of 1,000 m² or more; building-level solutions that draw on on-site renewables, a shared geothermal or ambient loop, or a district-heating connection, again across at least four buildings that size; or district-level network connections that add heat storage and bring in energy communities. Every project demonstrates in two different climate zones and reports the environmental, social and economic case to the local community and the heating operators.