2nd Jun 2025

New Permitted Development Rules for Air Source Heat Pumps (ASHPs) – Effective May 29, 2025

As of May 29th, 2025, the UK Government has introduced major updates to permitted development rights for air source heat pumps (ASHPs). These changes are designed to make installations simpler, more accessible, and to accelerate the nation’s transition toward low-carbon, energy-efficient heating systems.

If you’re considering switching to a renewable heating system, these relaxed planning rules make it easier than ever to install a heat pump at your home.

Key Changes to Air Source Heat Pump Permitted Development Rules

1. Removal of the 1-Metre Boundary Rule

Previously, air source heat pumps had to be installed at least one metre from any property boundary. This restriction has now been removed, making installation possible even on smaller plots, terraced houses, or flats where outdoor space is limited.

2. Increased Maximum Unit Size

The maximum size limit for ASHP units has increased from 0.6 cubic metres to 1.5 cubic metres. This allows homeowners to install larger and more efficient models, improving performance particularly for bigger homes or properties in colder regions.

3. Two Units Allowed on Detached Homes

Detached houses can now install up to two air source heat pumps without requiring planning permission. This update is especially useful for systems that combine heating and cooling (air-to-air heat pumps) or for homes with higher energy demands.

4. Support for Air-to-Air Heat Pumps

The new regulations now explicitly permit air-to-air heat pumps, which provide both heating and cooling, offering homeowners a versatile, all-year-round comfort solution.

5. Compliance with MCS Planning Standards

Although the rules are more flexible, all installations must still comply with the Microgeneration Certification Scheme (MCS) planning standards, including:

• Maintaining noise levels within legal limits.
• Ensuring the system is used solely for domestic heating and hot water purposes.

Financial Support: Boiler Upgrade Scheme

Homeowners in England and Wales can benefit from the Boiler Upgrade Scheme, which offers a £7,500 grant to help cover the cost of installing an air source heat pump. This financial support makes the transition to clean heating technology more affordable and accessible for households across the country.

Enhanced Consumer Support and Tools

To help homeowners make informed decisions, the government has introduced improved guidance and online resources, including:

• The Heat Pump Home Suitability Tool to assess if your property is suitable for a heat pump.
• The Find Ways to Save Energy in Your Home platform offering tailored advice on energy efficiency and sustainability upgrades.

Important Considerations for Homeowners

While the updated permitted development rules simplify installation, homeowners should still ensure compliance with all relevant planning and environmental regulations, including:

• Avoiding installation in conservation areas, World Heritage Sites, or on listed buildings.
• Meeting noise control standards.
• Using the heat pump solely for domestic heating or hot water.

Making the Switch to Sustainable Heating

These 2025 changes mark a significant step toward the UK’s goal of net zero emissions, removing key barriers for households to install low-carbon heating systems.

If you’re planning to install an air source heat pump, DWG Plans can provide planning support, site assessments, and documentation to ensure your installation complies with the new permitted development regulations.

Ready to upgrade your home heating system?
Contact DWG Plans Sussex today for expert advice on heat pump installations, permitted development compliance, and Boiler Upgrade Scheme grant applications.

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