This is particularly important when considering external equipment such as solar panels, heat pumps and air conditioning units. Listed buildings, conservation areas, flats, unusual installations and properties where permitted development rights have been restricted may all require additional consideration.

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This guide relates primarily to the planning system in England, where the rules described below apply. Planning requirements differ elsewhere in the UK.

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Solar panels planning permission

 

One of the most common questions homeowners ask is:

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Do solar panels need planning permission?

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In many cases, the answer is no.

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Solar panels installed on residential buildings or within residential land can often be installed as permitted development, provided the installation meets the required conditions.

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For panels mounted on a pitched roof, they should generally not project more than 200mm beyond the roof slope and should not extend above the highest part of the roof, excluding the chimney. Different limits apply to flat roofs, where the highest part of the solar equipment must generally be no more than 600mm above the highest part of the roof.

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The intention is that solar equipment should, so far as reasonably practicable, be positioned to minimise its effect on the external appearance of the property and the surrounding area.

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That means a standard solar installation on an ordinary house can be relatively straightforward from a planning point of view, but more prominent or unusual installations may need closer examination.

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Ground-mounted solar panels planning permission

 

Not every solar installation goes onto a roof.

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Homeowners with larger gardens, rural properties or poorly orientated roofs may consider ground-mounted solar panels instead.

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Ground-mounted solar installations can also benefit from permitted development rights, but the rules are different from roof-mounted panels.

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For a domestic property, only the first stand-alone solar installation can normally qualify. The equipment must generally be no higher than four metres and must be at least five metres from the property boundary. Additional restrictions apply in conservation areas and other protected locations.

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This makes the position of ground-mounted solar panels particularly important.

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A system positioned well within a large garden may be relatively straightforward. A system close to neighbouring properties, the road or an important landscape may require a different approach or a planning application.

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Solar panels in conservation areas

 

Living in a conservation area does not automatically prevent you from installing solar panels.

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Roof-mounted solar panels can often still qualify as permitted development, but their location and visibility become more important and additional restrictions can apply.

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The character of the building and the wider conservation area should therefore be considered at an early stage.

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Where a property is listed, the position is more sensitive. Listed building consent may be required and permitted development rights are more restricted, particularly where equipment is installed on the listed building or within its curtilage.

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For historic properties, good design and careful positioning can make a significant difference.

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Heat pump planning permission

 

Another rapidly growing area of interest is heat pump planning permission.

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Air source heat pumps can often be installed on domestic properties under permitted development rights, meaning that a conventional planning application is not always required. However, the installation must satisfy a number of specific conditions.

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The permitted development rules for air source heat pumps were expanded in England in 2025, giving homeowners greater flexibility to install systems without making a planning application.

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The current rules distinguish between different types of property. A detached house can potentially have its first two qualifying air source heat pumps under permitted development, while a non-detached house or qualifying block of flats is generally limited to the first installation.

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There are also limits relating to the size and position of the outdoor compressor.

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Air source heat pump permitted development

 

To qualify as air source heat pump permitted development, the installation must satisfy the relevant planning standards and siting requirements.

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Current rules in England include requirements relating to MCS planning standards, the volume of the outdoor compressor unit, roof positioning and the effect of the equipment on the appearance and amenity of the surrounding area.

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Air source heat pumps are not permitted development on pitched roofs. On a flat roof, the equipment must generally be positioned at least one metre from the external edge of the roof. There are also additional restrictions affecting listed buildings, scheduled monuments, conservation areas and World Heritage Sites.

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This is why the location of the external unit should be considered as part of the design rather than simply choosing the most convenient position for the installer.

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Noise, visibility and the relationship with neighbouring properties should all form part of that decision.

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Ground source heat pump planning permission

 

Ground source heat pumps work differently because most of the system is installed below ground.

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Domestic ground source heat pump installations can often be carried out without a full planning application, although the scale of excavation, the property and any planning or heritage restrictions still need to be considered.

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Larger systems, communal installations and systems associated with non-domestic properties may require a different planning assessment.

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As with any major green home upgrade, it is sensible to establish the planning position before committing to equipment or excavation work.

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Air conditioning planning permission

 

The rules surrounding air conditioning planning permission are particularly worth checking before installation.

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Modern systems are increasingly capable of both cooling and heating. Where a system operates as an air source heat pump and provides a heating function, it may potentially benefit from the permitted development rights available for qualifying air source heat pumps, provided all of the relevant conditions are satisfied.

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However, a system that provides cooling only does not benefit from those air source heat pump permitted development rights and a planning application will generally be required.

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This distinction is important.

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Someone searching for aircon planning permission may assume that all external air conditioning condensers are treated in the same way. They are not.

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The function of the equipment, its size, its position and the type of property all need to be considered.

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Air conditioning units and neighbouring properties

 

External air conditioning and heat pump equipment can also raise planning concerns because of noise and visual impact.

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Positioning a unit next to a neighbour's bedroom window is very different from locating the same equipment discreetly at the rear of a detached house.

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Even where permitted development rights appear to apply, the equipment must meet the relevant conditions, including requirements intended to minimise its impact on the building and surrounding amenity.

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Good planning at the outset can therefore help avoid neighbour objections and unnecessary redesign later.

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Planning permission in conservation areas

 

Conservation areas require additional care because the appearance and character of the area forms an important part of the planning assessment.

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This does not mean that green technology is prohibited.

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Solar panels, heat pumps and other sustainable improvements can often be accommodated successfully, but their position, visibility, materials and effect on the building may need much more careful consideration.

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For example, equipment positioned discreetly on a rear elevation may have substantially less visual impact than the same equipment positioned prominently on the front of a house.

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The best solution is often not to abandon the green technology, but to design the installation around the planning constraints of the property.

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Listed buildings and green home upgrades

 

Listed buildings need an even more considered approach.

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Works that affect the special architectural or historic interest of a listed building can require listed building consent, and some permitted development rights available to ordinary homes do not apply in the same way.

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Solar panels, external heat pump units, new vents, insulation, replacement windows and alterations required for new services may all need to be considered carefully.

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A green upgrade to a historic home therefore needs to balance improved energy performance with the conservation of the building itself.

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When should you make a planning application?

 

If an installation does not comply with the relevant permitted development limits, this does not necessarily mean that the project cannot proceed.

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It usually means that a planning application needs to be made so that the local planning authority can consider the proposal on its merits.

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Depending on the project, a planning submission may need to demonstrate matters such as:

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• the position and dimensions of the proposed equipment

• its relationship to the house and neighbouring properties

• elevations showing how equipment will appear

• photographs of the existing building

• noise information where relevant

• heritage considerations in sensitive locations

• the visual impact of solar panels or external plant

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Clear drawings and a properly considered proposal can make it much easier for the planning officer to understand exactly what is being proposed.

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What if the work is permitted development?

 

Where the proposed work clearly falls within permitted development rights, a full planning application may not be required.

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However, homeowners sometimes want formal confirmation from the council before carrying out the work.

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In these circumstances, it may be possible to apply for a Lawful Development Certificate.

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A Lawful Development Certificate is not planning permission. It provides formal confirmation that a proposed or existing development is lawful for planning purposes. It can also provide useful documentation when a property is later sold.

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For higher-value installations, obtaining certainty before work begins can sometimes be worthwhile.

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Planning permission and Building Regulations are different

 

Planning permission is only one part of the process.

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A project that does not require planning permission can still need to comply with Building Regulations.

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Government guidance confirms that works including fixed air-conditioning systems, replacement windows and doors, heating systems and certain electrical alterations can fall within the Building Regulations regime.

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Solar installations, heat pumps, electrical equipment and structural alterations may therefore involve different technical approvals even when planning permission is not required.

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This is one of the reasons why green home upgrades are best considered as part of an overall project rather than as completely separate installations.

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Plan the upgrade before choosing the equipment

 

The planning question should ideally be answered before equipment is ordered.

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A homeowner may find the ideal heat pump only to discover that the preferred external location causes planning problems. A solar installer may propose the maximum possible number of panels when a more carefully designed arrangement would be better for a conservation area. An air conditioning contractor may position condensers where they create unnecessary visual or noise issues.

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A little planning work at the beginning can prevent considerably more work later.

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How APN Green Homes can help

 

APN Green Homes takes a whole-home approach to energy and sustainability improvements.

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Rather than looking only at an individual product, the aim is to consider the property, the proposed technology and any planning or design implications together.

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That may include solar PV, heat pumps, air conditioning and heating systems, battery storage, improved glazing, insulation, ventilation, EV charging and other improvements that can make a home more efficient and better prepared for the future.

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Where planning input is required, the first step is to establish whether the proposed work is likely to fall within permitted development rights or whether a planning application, Lawful Development Certificate or other consent should be considered.

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Start with the right advice

 

Green home improvements should make your property better — not create unnecessary planning problems.

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Whether you are considering solar panels, a ground-mounted solar installation, an air source heat pump, air conditioning or a wider package of green home upgrades, establishing the planning position early can save time, cost and uncertainty.

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Planning a greener home? APN Green Homes can help you understand the property, the options and the approvals that may be required before the work begins.

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NEXT STEPS

Every home is different, so the right next step depends on your property, your budget and what you want to achieve. APN Green Homes can help you turn the information you have just read into a practical plan for your own home. Whether you are considering one improvement or looking at a complete whole-home energy upgrade, we can help you understand what is suitable, what should be prioritised and where your money is likely to make the greatest difference.

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Choose one of the options below to get the ball rolling:

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BOOK A GREEN HOME SURVEY
Get a detailed assessment of your home with practical, property-specific recommendations and a clear plan for the improvements worth considering.

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BOOK A PHONE CONSULTATION
Talk through your property, ideas and priorities with us and get some initial direction on the best way forward.

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EMAIL US
Send us details of your property, photographs or any questions and we can advise you on the most appropriate next step.

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GIVE US A CALL
Prefer to speak to someone? Give us a call and tell us what you are hoping to achieve.

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Your greener, more efficient home starts with understanding the right improvements for your property — and putting them in the right order.