From 29 May 2025, landlords will have a far easier time upgrading their rental properties with heat pumps, thanks to a major planning shake-up announced by the government. The revised rules, which aim to speed up installations and improve energy performance in homes, are designed to support landlords and homeowners alike in future-proofing their properties—without being bogged down in red tape.

Under the updated guidance, the government is scrapping the existing restriction that prevented air source heat pumps from being installed within one metre of a property boundary. In addition, the maximum size of air source heat pumps allowed under permitted development has been more than doubled—from 0.6 cubic metres to 1.5 cubic metres.

These changes, just weeks away from implementation, mean that landlords no longer need to apply for planning permission in most cases—cutting weeks or even months off the process.

Double installations now allowed for detached properties
Perhaps the most significant improvement for larger properties is the change allowing two air source heat pumps to be installed at once under permitted development rules. Previously, only one unit was permitted without planning approval—even in detached homes with higher energy demands.

By lifting this restriction, landlords of family-sized houses or HMOs can now benefit from cascade systems, which are increasingly being used in modern retrofitting projects. Additionally, air-to-air heat pumps—many of which can also provide cooling in summer—will now enjoy the same relaxed rules as air-to-water models, allowing more flexibility when tailoring energy upgrades to property type and tenant needs.

These updates come at a crucial time. Many landlords have been holding back on green upgrades due to bureaucratic delays and mounting costs. According to data from Swedish eco-technology company Aira, the average wait time for heat pump-related planning consent is around two months—but that’s only the average. In places like Westminster, Walsall and Birmingham, landlords can wait up to six months before getting the green light to install a system.

With a 600,000 target, government turns up the pressure
The UK government has committed to installing 600,000 heat pumps annually by 2028, a target that’s miles away from the estimated 100,000 installations recorded in 2024. It’s a massive gap to close—and ministers appear to be waking up to the fact that over-regulation has been one of the biggest obstacles.

For landlords, these rule changes remove a huge practical headache and support the broader transition to energy-efficient properties—especially as EPC standards tighten across the board. Landlords looking to future-proof their portfolios ahead of looming legislation on minimum energy performance standards should see this as an opportunity to act now, before supply chains and installers become stretched.

While these changes are certainly welcome, landlords still face challenges when it comes to cost, especially on older properties where insulation is poor or retrofitting is complex. But by scrapping planning delays and expanding the scope of permitted development, the government has at least removed one major barrier to progress.