More than one in four of Prince William’s rental properties are amongst the worst rated for CO2 emissions, a Mirror investigation has found.

Yesterday, a joint investigation with Channel 4 Dispatches showed that one in seven Duchy of Cornwall properties have the worst F and G ratings for energy efficiency, leaving tenants at risk of fuel poverty and living in cold, damp and mouldy homes. We can now reveal the huge amounts of carbon produced by the Prince’s least environmentally-friendly rental properties.

It comes as Prince William jets to South Africa to the Earthshot Prize he launched in 2020 “to search for and scale the most innovative solutions to the world’s greatest environmental challenges”. Our findings are awkward for the Prince but also for his father King Charles III who is green champion and spent 70 years “actively involved in running the Duchy”.

Environmental impact ratings run from A – the best – down to G and we have examined the ratings for nearly 500 residential rental properties in his Duchy of Cornwall property empire. More than 130 of them were rated F or G, the lowest ratings, when assessors last visited. Combined the 130 homes produced 1,596 tonnes of CO2 a year – more than double the average.

Prince William’s holiday cottage in Cornwall ( 
Image:
Duchy of Cornwall)

But, if William followed the suggestions of the energy assessors who visited the properties, this could be reduced to just 491 tonnes, a 69% saving in carbon emissions. The 1,105 tonnes of CO2 saved a year would be the equivalent of the emissions from 184 average homes, or 987 flights to New York or planting 110,000 trees.

Andrew Parkin, technical director at Elmhurst Energy, said: “Many of the properties are off grid so will be using the worst emitting heating sources such as coal and wood fires, or older oil central heating systems.

Images showing the condition inside a Duchy of Cornwall property
“These circumstances make them more complicated to decarbonise, but it is still feasible to improve these buildings to reduce the amount of energy required to heat them, improving warmth and comfort and reducing costs and carbon emissions.

“20% of the UK’s carbon emissions come from heating our housing stock, so it’s right that homeowners, as well as landlords who make an income from renting residential property, try to reduce the carbon emissions from the homes they own. Doing so is a vital step towards the country achieving its net zero targets.”

One Duchy farmhouse rated “G” produces 74 tonnes of CO2 a yearOne Duchy farmhouse rated “G” produces 74 tonnes of CO2 a year but it could be improved to a B. It’s “potential production” of CO2 after these improvements could be just 2.4 tonnes. A Duchy of Cornwall spokesperson said:“Environmental sustainability and supporting our tenants and communities is at the heart of all our decision making.”Over the last five years, the Duchy says it has reduced carbon production by 300 tonnes in its residential and rural commercial buildings. The spokesperson added: “Prince William became Duke of Cornwall in September 2022 and since then has committed to an expansive transformation of the Duchy. This includes a significant investment to make the estate net zero by the end of 2032.”

Barry Gardiner, Labour MP and member of the House of Commons Environmental Audit Committee, said it was “very strange” that the Duchy of Cornwall had “not adopted best practice here, never mind their legal minimum obligation”. He added: “Failing properties cause real health problems for those who have to live in them and take an enormous financial toll on families trying to heat a home that is leaking energy.”

Our investigation with Channel 4 Dispatches and the Sunday Times revealed that the two royal Duchies of Cornwall and Lancaster, owned by Prince William and King Charles III, earn millions of pounds in rent from the taxpayer. It includes £11.4m from an NHS Trust, £37.5m for a prison, and hundreds of thousands of pounds for a string of schools.