What the updated planning rules mean for homeowners and installers
From 29th May, new planning rules will come into effect in England and Wales, making it simpler for homeowners to install air source heat pumps without needing planning permission. The update forms part of the government’s Warm Homes Plan and is designed to help remove barriers to low carbon heating.
These changes are welcome news for homeowners looking to switch to a more energy-efficient solution, and for installers supporting that transition. With less red tape and more flexibility, heat pumps are now an even more practical choice for a wider range of properties.
Larger heat pumps such as the Samsung HT Quiet will no longer require planning permission.
How Planning Rules Complicated Heat Pump Installations
Homeowners looking to install an air source heat pump have often faced numerous planning challenges, particularly if their property didn’t meet the strict criteria for permitted development.
Under the previous regulations, a heat pump had to be installed at least one metre from the property boundary to qualify for permitted development status. This posed a significant barrier, especially in urban or compact areas where space is limited.
On top of that, the maximum allowable external volume for a heat pump was just 0.6 cubic meters, a limit that many modern systems, especially for larger or older homes, exceeded. As a result, even standard installations often required full planning permission.
Additionally, while a single air source heat pump could be installed without issue, homes requiring two units had to seek separate planning approval for each unit.
Key Changes to Permitted Development Rights in 2025
From 29th May, these issues will no longer plague homeowners, making it simpler to install air source heat pumps without needing planning permission. Here are the main changes you need to be aware of:
One-metre restriction is being removed - Heat pumps can now be installed closer to a property boundary. which opens up new installation options, particularly for smaller plots.
Volume Limit Increased to 1.5 Cubic Metres - The maximum size for a permitted air source heat pump is increasing. Systems up to 1.5 m³ will be allowed, more than doubling the previous volume limit.
Two Units Now Allowed for Detached Homes - This will benefit homes that use cascade systems, allowing them to take advantage of the same permitted development rights as a single unit.
Air-to-Air Heat Pumps Now Included - Air-to-Air systems will now enjoy the same planning allowances as air-to-water heat pumps.
Cascaded systems will no longer require planning permission for detached homes.
What the Changes Mean for Homeowners and Installers
Permitted development rights allow homeowners to proceed without hurdles. That’s why the upcoming changes are so significant. They remove a key barrier that has previously added both cost and uncertainty to heat pump projects.
The changes make it much easier for people to upgrade their heating system with fewer delays or administrative hurdles.
For installers, this means more homeowners are likely to be interested in installing a heat pump, but also, projects are more likely to go ahead.
For homeowners, it means greater freedom to choose the system that works best for their property, with less hoops to jump through.
Need Help with a Heat Pump Installation?
At Alto Energy, we specialise in the design and installation of air source heat pumps that meet both current regulations and the evolving needs of modern homes. Whether you're planning a new system or adjusting to the recent changes, our expert team can guide you through every step.
We work closely with homeowners, installers, and developers to ensure that every project is efficient, cost-effective, and future-ready.
Get in touch with us today to learn how we can support your next heat pump project.
Heat Pump Training
If you're looking to learn how to install air source heat pumps, we offer free heat pump training on leading brands like Worcester Bosch, Samsung and Mitsubishi.