Renewable energy systems — including heat pumps, solar photovoltaic (PV) panels, and solar thermal systems — are included in EPC calculations. Under RdSAP 10, these renewable systems are assessed in greater detail than before, with improved modelling for system type, efficiency, and interaction with your home’s heating and electricity demands.

However, EPC ratings are based on calculated energy running costs, not carbon emissions. This means the actual impact on your EPC band depends on how much the renewable system reduces those estimated costs.

• Heat pumps can improve an EPC rating if they replace less efficient heating systems.

• Solar PV systems are now modelled more accurately under RdSAP 10. The rating considers system size, orientation, overshading, and whether the system is connected to the properties supply. Having a Solar PV system is likely to improve your EPC rating.

• Battery storage systems, while recorded, currently have little or no effect on the EPC rating.

• Solar thermal systems can contribute positively as they typically offset a significant proportion of hot water demand, particularly in homes with high usage.

If you’re planning to install renewables, it’s best to consult a qualified EPC assessor beforehand. They can advise how the improvements are likely to be reflected in your rating.