Decarbonising heat is a challenge due in part to the large number of actors such as individual homeowners. In this paper, we explore the use of Geographical Information Systems (GIS) to identify opportunities for heat decarbonisation. We demonstrate the approach for the residential sector in Ireland, where 64% of the population lives in urban locations and the potential for ground source heat pumps is limited by access to land. In contrast, access to the gas network limits opportunities for gas-fired central heating in rural locations. This paper explores how GIS approaches can be combined with spatial data to identify opportunities to decarbonise heat, providing useful insights and recommendations for policymakers on suitable locations for low-carbon heating technologies.