Phase two will be looking at solar power, maybe a battery, and replacing my now ancient gas hot water tank (I'm thinking of offering it to a museum). PV panels will make power much cheaper when the sun is shining, the battery will keep it cheap when it isn't, and I'll be able to get a cheaper resistive hot water tank rather than an expensive and less reliable heat pump jobbie.
The report says my gas HWS alone is responsible for 50% of my house's energy usage, so that has to GTFO ASAP.