This project explores the use of novel algorithms to inform a Heat as a Service (HaaS) business model. The project will demonstrate how the HaaS business model will accelerate energy retrofit and heat supply solutions in domestic properties. The project builds on an innovative, cutting-edge thermal modelling capabilities to develop a new application, demonstrating a viable Heat-as-a-Service (HaaS) business model. Based on a calibrated, detailed and disaggregate understanding of the property energy use, the project will develop simulation to evaluate technical and financial impact of alternative provision of domestic heat and identify how these can be financed to accelerate decarbonisation. The HaaS solution will include provision of heat comfort via: * Energy efficiency retrofit measures * Electrification of heat via heat pumps * Boiler replacement * District heat. The solution will identify the most viable solution for the provision of heat in the property using detailed research from financing of energy efficiency measures in the domestic sector, enabling a single customer interface through which retrofit and low carbon heat measure can be financed and accelerated. The Chancellor has announced a £2bn Green Homes Grant to help the country build-back better, creating jobs and a sustainable recovery. Our solution will extend the options for domestic retrofit, in particular focusing on the decarbonisation of heat, specifically addressing the theme of improving the energy efficiency, heating and cooling of our homes and other buildings.