Nick Sommerlad

A Guardian investigation found that 630 of more than 700 examined rental properties across the Duchies of Cornwall and Lancaster and the Sandringham estate had energy performance ratings below the government’s proposed minimum of EPC C by 2030. Upgrading potentially more than 1,000 properties could cost King Charles III and Prince William up to £10m, with individual estates facing bills estimated at up to £5m, £2m and £3m respectively. The royal estates say they are investing in maintenance, retrofits and new energy-efficient homes, while campaigners argue they should lead by meeting the standard and closing regulatory loopholes. The government has yet to finalize the rules and exemptions, particularly for historic and mixed-use buildings.