Watts-ON Consultants are busy with decarbonisation projects for the public sector. The most popular choice for the NHS is the application of high temperature cascading heat pumps (Ground and Air source) to replace existing gas fired boilers. These projects often involve the connection of multiple buildings within a districtheating network to a centralised high temperature heat generator. The carbon savings are achieved as the heat pump will use “lowcarbon electricity” (thanks to the integration of #renewables in the UK electrical network) instead of natural gas. As happened many times over, funding for these projects are made available for a short period of time which makes difficult for the team to prepare with the ideal pace. Nevertheless, Giovanni Lupaldi had the possibility to take measurements of the real building loads to establish the real district heating capacity. This operation will unlock the capacity optimisation of the future heat pump saving CAPEX for the client and energy for the users. Capital will be saved as the new heat generator will not be sized upon the current gas boilers but it will be smaller. Energy will be saved because the new HP will operate at its optimal regime as it is sized for the building real heat demand.