Most Homes that have to qualify for ECO4 will need to have an Energy Performance Certification (EPC) ranking of D or down below. The ranking means your property has actually been measured up in terms of its efficiency to avoid wasting energy and how your property makes use of energy, https://ukgovenergygrants.fitness.blog/2025/07/20/solar-energy-grants-uk-government-support-for-greener-homes/