Planning Permission Simplified — What the May 2025 Rule Changes Mean for Heat Pump Installations

Posted on October 9th, 2025

Outside of a home with a heat pump installed on the ground.

In May 2025, the UK Government introduced a landmark update to planning regulations that directly affects the installation of air source heat pumps (ASHPs). These changes are designed to accelerate low-carbon heating adoption across domestic properties — especially in urban and council-owned housing stock. For local authorities, this marks a turning point in retrofit feasibility, cost reduction, and delivery speed.

What’s Changed?

The updated regulations, part of the Warm Homes Plan, remove several long-standing barriers:

  • 1-metre boundary rule scrapped: ASHPs can now be installed closer to property boundaries without planning permission.
  • Size allowance increased: Units up to 1.5m³ are now permitted, enabling higher-capacity systems.
  • Dual installations allowed: Detached homes may now install two ASHPs without triggering planning constraints.
  • Air-to-air heat pumps included: Systems offering both heating and cooling are now covered under permitted development rights.

These changes simplify the process for councils and housing providers, particularly in dense urban areas where space constraints previously made installations unviable.

Why It Matters for Councils

  • Faster project timelines: No need to wait 8–10 weeks for planning approval.
  • Broader property eligibility: Terraced homes, flats, and mixed-tenure buildings can now be considered.
  • Improved EPC ratings: ASHPs contribute significantly to achieving EPC Band C — a key target under ECO4 and SHDF schemes.
  • Reduced administrative overhead: Streamlined compliance means fewer delays and lower costs.

Compliance & Quality Assurance

While planning permission may no longer be required, councils must still ensure:

  • Noise limits are met: Installations must comply with acoustic standards under BMCS 020a.
  • PAS 2035 coordination: Retrofit designs should be overseen by certified professionals to ensure long-term performance and resident safety.
  • TrustMark registration: All installers should be accredited to guarantee workmanship and consumer protection.

Conclusion

The May 2025 planning update removes a major hurdle for councils seeking to decarbonise housing stock. With fewer restrictions, faster delivery, and broader eligibility, air source heat pumps are now a practical and scalable solution for local authorities across the UK.

For more information on our air source heat pump services, or to discuss retrofit coordination for your housing portfolio, please get in touch with our team.

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