Millions of historic homes across England could fall into disuse unless ministers urgently reform the heritage planning system, according to a new report from Grosvenor.
The property group says slow, complex and inconsistent planning rules are blocking even basic energy-efficiency upgrades to listed homes in conservation areas, suggesting planning reforms are no longer necessary but vital to ensure they remain in liveable conditions.
With rising energy costs and growing pressure to cut carbon, Grosvenor argues the current system is no longer protecting heritage – it is actively putting it at risk.
Historic homes ‘trapped in cold, costly decline’
In its new report, Retrofit or Ruin, Grosvenor warns that England’s three million listed buildings and conservation area homes are being held back by an outdated National Planning Policy Framework that treats low-risk energy improvements as high-risk interventions.
Homeowners must currently apply for Listed Building Consent to install measures such as secondary glazing, insulation or heat pumps, even where approval is almost guaranteed.
New research shows local authorities spend the equivalent of 4,000 working days each year processing these applications, despite 93% being approved. Only one in three decisions is made within the required eight-week timeframe, delaying work that could cut energy bills, reduce emissions and improve comfort.
“Historic buildings only survive if they can adapt,” said Tor Burrows, Chief Sustainability Officer at Grosvenor. “If they are cold, expensive to run and difficult to upgrade, they risk falling into disuse. Once that happens, heritage is lost.”
Planning delays slow climate action
The report highlights widespread inconsistency across the planning system, with homeowners often facing a lottery when seeking consent for similar retrofit measures.
Only 16% of local authority officers surveyed said they felt very confident making decisions on heritage retrofit, while 87% of historic building owners see the planning system as a major barrier to renovating their listed building.
Grosvenor argues that this slow, case-by-case approach is fundamentally incompatible with the scale and urgency of the climate challenge.
Independent analysis suggests that retrofitting historic buildings across England and Wales could cut operational carbon emissions by up to 7.7 million tonnes of CO₂ each year – around 30% of the annual reductions needed to meet the UK’s Sixth Carbon Budget.
“The real issue now is speed and scale,” Burrows said. “Retrofitting historic buildings needs to happen across millions of buildings, not slowly, one application at a time.”
Calls for automatic consent grow
To unlock progress, Grosvenor is calling for the biggest reform of heritage planning in more than 35 years. Central to its proposals is the introduction of a National Listed Building Consent Order, which would grant automatic consent for low-risk, high-benefit, energy-efficiency measures.
It also recommends new Local Development Orders to streamline planning in conservation areas, alongside a national programme to boost heritage skills and capacity in local authorities.
The reforms, Grosvenor says, would help ensure historic homes are not excluded from the Government’s £15bn Warm Homes Plan. “A system that requires individual approvals for routine retrofit interventions which are almost always approved but take months to process is no longer protecting heritage,” Burrows said. “It is holding back climate action.”
Grosvenor will launch the report at the Houses of Parliament later this month.
