Planning rules play a quiet but significant role in whether households can install a heat pump. This is because applying for planning permission adds cost, time, and friction to the process of acquiring a heat pump. Whether homeowners go through the application process or take steps to avoid it by changing the location of their heat pump – planning can make the complex process of heat pump installation even harder.

The Welsh Government’s response to its consultation on changes to permitted development rights, to which Nesta responded, contains welcome proposals to make it easier for homeowners to install an air source heat pump (ASHP) without submitting a planning application.

We’re encouraged to see that Welsh Government is relaxing this process to support homeowners with installing clean heat technologies. But with a new Senedd on the horizon, there is an opportunity to go further and take an even more forward-looking approach to regulations.

Here is a breakdown of what is going to change, what is not, and what we think the future Senedd could do to make heat pump adoption easier for homeowners.

Owing to a restrictive requirement to locate an ASHP at least three metres from a neighbouring property’s boundary, Wales stood out from other GB nations when it came to planning rules. While we are still awaiting information on when changes are to be implemented, the Welsh Government's proposal to abolish the distance-based requirement in its response will bring an end to this issue.

Other changes were also accepted by Welsh Government that will bring Wales in line with the rest of Great Britain. Permitted development rights in Wales will now extend to air-to-air heat pumps, which previously required a planning permission due to a rule that heat pumps only be used for heating purposes. We support this change, as it will help future-proof Welsh homes for hotter summers and make heat pumps more accessible.

ASHPs will also now fall under permitted development rights if they are up to 1.5 cubic metres in size, instead of 1 cubic metre, creating an opportunity for quieter models and for installations better suited to more properties. Detached properties will be able to accommodate up to two heat pumps instead of one, and homeowners will be able to put up to two heat pumps on a wall of their property if it faces a highway. The new rules emulate recent changes to regulation in England, and give Welsh homeowners welcome flexibility.

Alongside these changes, however, there are three ways we think Welsh government should go further for a more proactive approach to regulation.

Despite clear support in consultation responses, the Welsh government decided against relaxing planning permissions to install a heat pump within the boundaries of a property with an existing wind turbine. The reason given was concern about noise and potential visual impacts of ASHPs.

This is a disappointing outcome, for a couple of key reasons.

First, encouraging co-siting of ASHP and wind turbines would actively support decarbonisation. It would give homeowners the opportunity to heat their home using clean energy whilst reducing reliance on the grid. At a time when it’s important to make low carbon choices easier, this feels like a missed opportunity.

Second, concerns about ASHPs visual impact don’t quite stack up. While installers should be mindful when installing heat pumps in areas with important visual characteristics - such as conservation areas - there is no reason to penalise their installation on the grounds of visual impact in other areas. Currently, homeowners do not need to apply for planning permission to install a wind turbine (provided there is only one, and it meets certain criteria), but are required to ‘minimise its effect on the amenity of the area’. Providing homeowners have respected this condition, it is unclear what compounded aesthetic impact would come from the installation of a heat pump in the same property. Further, heat pump installations must abide by MCS 020(a) sound level standards, and there is no reason to restrict installation on the grounds of acoustic disturbance if they meet existing regulations.

Installing heat pumps in blocks of flats comes with its own challenges, due to their different layout, limited outdoor space and the fact that almost all flats are owned through leasehold, requiring the consent of the freeholder to undertake works. These differences all make ASHP installation far less straightforward than in a typical home.

However, sticking to the status quo - which currently allows for only one ASHP installation to fall under permitted development rights on a whole block of flats - leaves a lot of potential untapped, and the regulations shy away from proposing a comprehensive strategy to address this. Nesta is currently exploring this question, and will publish some early findings later this Spring.

Homeowners living in conservation areas and listed buildings will continue to face more restrictive conditions, requiring the submission of a planning application to install a heat pump on a wall or roof or within their property’s boundary if facing a highway. We believe the next Welsh Government should take action to change this.

Rather than restrict such developments indiscriminately, we recommend that the future government provides guidance on sympathetic installations in historic contexts, similarly to Historic England, or uses phrasing to request additional measures to minimise visual impact.

It is possible to conceal or modify a heat pump to make it blend in its surroundings and preserve a property’s visual identity. So, it doesn’t feel fair to add barriers to residents wishing to install heat pumps in a conservation area. As Wales continues to advance on its journey towards clean energy and heating, heat pumps will become as commonplace as rubbish bins, gas meters or satellite dishes - all of which can be used without similar restriction in conservation areas.

The Welsh Government’s response to its consultation on permitted development rights shows it’s making an effort to strike a challenging balance between making it easier to decarbonise homes while protecting Wales’ many sites of natural and historical beauty.

As heat pump adoption ramps up, there is a real opportunity for the next Senedd to adopt proactive regulations that will allow homeowners to benefit from low-carbon technologies, while future-proofing the unique character of Welsh towns and cities for years to come.