New Air Source Heat Pump Planning Rules in Wales: Permitted Development Changes from June 2026

Robert Harvey
5 minutes ago
4 min read

From 1 June 2026, significant changes to permitted development rights (PDR) for air source heat pumps have come into effect across Wales. The updates are designed to make it easier for homeowners to install low-carbon heating systems without the need for a full planning application.

We've already posted one blog on the subject, but this is such a big change we are so excited to write about it twice. This time, we've presenting it as a list for those who like an easy read.

For homeowners considering an air source heat pump and for installers working across Wales, these changes remove several common planning barriers and support the wider transition towards renewable heating.

What Are Permitted Development Rights?

Permitted development rights allow certain types of home improvements to be carried out without applying for full planning permission.

For air source heat pumps, these rights determine where units can be installed and what restrictions apply.

The latest Welsh Government changes to the legislation provide greater flexibility for both homeowners and renewable energy installers.

Key Changes to Air Source Heat Pump Planning Rules in Wales

1. The 3-Metre Boundary Rule for Heat Pumps Has Been Removed

One of the biggest changes is the removal of the previous requirement for air source heat pumps to be located at least three metres from a property boundary.

Under the new rules, heat pumps can now be installed anywhere on the property, provided they comply with the latest MCS 020(a) noise assessment standards.

This gives homeowners far more flexibility when choosing the most suitable location for their system, and makes them compatible options for more homes, particularly terraced houses.

2. Highway-Facing Installations Are Now Allowed

Previously, installing an air source heat pump on a wall or roof facing a highway often required planning permission.

As of 1 June 2026, this restriction has been removed for properties outside conservation areas. Find out if your property is in a conservation area, use Heritage Check, or the local authority website.

This opens up additional installation options and can help overcome site-specific challenges where space is limited.

3. Detached Homes Can Install Two Heat Pumps

The previous rules limited detached properties to a single heat pump installation under permitted development rights.

The updated regulations now allow two heat pumps on detached homes. However, both units operating together must still meet the MCS 020(a) noise limit of 40dB.

This change is particularly beneficial for larger properties with higher heating demands.

4. Larger Heat Pumps Are Now Permitted

The maximum size allowance for domestic heat pumps has increased from 1m³ to 1.5m³.

This reflects advances in heat pump technology and provides greater flexibility when selecting systems for larger homes or properties with higher heat requirements.

5. Air-to-Air Heat Pumps Are Now Included

Another important update is the inclusion of air-to-air heat pumps within permitted development rights in Wales.

This means homeowners can benefit from a wider range of low-carbon heating and cooling technologies without needing a full planning application.

It's worth noting that MCS certification requirements for air-to-air heat pumps are still being finalised, so installers and homeowners should keep an eye on further announcements from MCS regarding implementation timelines.

What These Changes Mean for Homeowners

For many homeowners, these changes will make air source heat pump installations simpler, quicker, and more cost-effective. Fewer planning restrictions mean more properties are likely to qualify under permitted development rights, reducing delays and administrative costs.

Combined with ongoing government support for renewable heating technologies (such as the Boiler Upgrade Scheme, or the Welsh Government supported Green Home Wales 0% loan), the updated regulations should help accelerate heat pump adoption across Wales.

What Installers Need to Know

While the planning rules have become more flexible, compliance with MCS standards remains essential.

Noise assessments under MCS 020(a) will continue to play a key role in determining whether a proposed installation qualifies under permitted development rights.

Installers should review the updated guidance carefully and ensure all system designs meet current certification and noise requirements.

Our Reflections on the New Rules

From our perspective as heat pump installers working in Swansea, Neath Port Talbot, Brecon, Bridgend, Cardiff and Carmarthenshire, these changes are a welcome step forward. They represent one of the most significant updates to air source heat pump permitted development rights in Wales in recent years. It also brings us inline with England.

By removing the 3-metre boundary restriction, allowing highway-facing installations, increasing size limits, permitting two units on detached properties, and including air-to-air heat pumps, the Welsh Government has made it easier than ever for homeowners to adopt renewable heating technologies.

That said, it's important to understand that the MCS 020(a) noise assessment remains the key requirement. In reality, sound compliance is now the most important factor when determining whether an installation qualifies under permitted development rights. A well-designed system, correctly specified and positioned, will be essential to ensure compliance.

For the vast majority of properties outside conservation areas, these changes should make the process considerably simpler. More homes will be able to install heat pumps without the uncertainty, cost, and delays often associated with planning applications.

If you're considering an air source heat pump installation in Wales, now could be an ideal time to explore your options.

Thinking About Installing a Heat Pump?

If you're considering an air source heat pump for your home and want to understand how these new permitted development rights affect your property, we're here to help.

We can assess your home's suitability, carry out the necessary MCS noise calculations, and advise whether your installation is likely to qualify under permitted development rights.

Whether you're replacing an existing heating system or exploring renewable heating for the first time, we can guide you through the process from initial survey to installation.

Call us on 01792 361638 to book your free site survey.

Book a free phone consultation and have your questions answered.

Email us on info@limitless-energy.co.uk