As of May 29th 2025, the UK government has implemented significant changes to permitted development rights for air source heat pumps (ASHP’s), aiming to simplify installations and encourage the adoption of low-carbon heating solutions.

Key Changes to Permitted Development Rights

1. Removal of the 1 metre boundary rules

Previously ASHP’s had to be installed at least 1 metre from any property boundary. This restriction has been lifted, allowing homeowners with limited outdoor space, such as those in terraced houses or flats, to install heat pumps more easily.

2. Increased unit size limit

The maximum allowable size for an ASHP unit has been increased from 0.6 cubic metres to 1.5 cubic metres. This change accommodates larger and more efficient models, which can be particularly beneficial for larger homes or areas with colder climates.

3. Allowance for 2 heat pumps on detached homes

Detached properties are now permitted to install up to 2 ASHP’s without the need for additional planning permission. This flexibility supports systems that require multiple units, such as air-to-air heat pumps that also provide cooling.

4. Support for Air-to-Air Heat Pumps

The new regulation supports the installation of air-to air heat pumps, which can provide both heating and colling, offering a versatile solution for year-round comfort.

5. Compliance with MCS planning standards

Installations must still comply with the Microgeneration Certification Scheme (MCS) planning standards, ensuring that noise levels are kept below specified thresholds and that the equipment is used solely for domestic heating or hot water purposes.

Additional Support Measure

• Boiler Upgrade Scheme Grant
Homeowners in England and Wales can apply for a £7500 grant through the Boiler Upgrade Scheme to help cover the cost of installing a heat pump.

•  Enhanced Consumer Guidance
The government has committed to improving consumer advice tools, including the “Heat Pump Home Suitability Tool” and the “Find Ways to Save Energy in your Home” platform, to help homeowners make informed decisions.

Considerations for Homeowners

While these regulatory changes facilitate the installation of AHSP’s, homeowners should ensure that their property complies with all the relevant conditions, such as avoiding installations in conservation areas, World Heritage Sites, or on listed buildings. Additionally, adherence to noise standards and proper usage for domestic heating or hot water is required.

For detailed guidance and to check eligibility for grants, homeowners are encouraged to consult the official government resources and planning tools.

Why not get in contact with DWG Plans and we can help you with plans and building regulations for your loft conversion.

Call DWG Plans on 0800 688 9345 or get in touch online today.