Air Source Heat Pump Planning Permission UK: Do You Need It?

Over 90% of domestic air source heat pump installations in England need no planning application at all. Permitted development covers most situations — but there are specific conditions around noise, placement, and property type that you must meet. Get them wrong and your local council can require removal. Here is the full picture.

One of the most common questions homeowners ask before installing an air source heat pump is whether they need planning permission. The good news is that most domestic air source heat pump installations in England do not require a formal planning application — they fall under "permitted development." But there are conditions, and getting them wrong can cause problems.

This guide covers the full picture: what permitted development allows, what the conditions are, when you do need to apply for planning permission, and how the rules differ across the UK.

What Is Permitted Development?

Permitted development is a set of rights that allow homeowners to make certain changes to their property without needing to apply for planning permission. It covers things like small extensions, loft conversions (within limits), and — relevant here — the installation of certain types of renewable energy equipment, including air source heat pumps.

The key legislation is the Town and Country Planning (General Permitted Development) (England) Order 2015, specifically Part 14 (Class G for air source heat pumps). Scotland, Wales, and Northern Ireland have their own rules, which we cover later in this guide.

Permitted Development Conditions for Air Source Heat Pumps in England

You can install an air source heat pump without planning permission in England, provided all of the following conditions are met:

1. Number and Size of Units

Since 29 May 2025, permitted development in England allows up to two air source heat pumps on a detached house and one on other houses. Each outdoor compressor unit can be up to 1.5 cubic metres in volume (0.6 cubic metres on a block of flats). Going beyond these limits needs planning permission.

2. The Unit Must Comply With MCS Planning Standards

The heat pump installation must comply with the MCS Planning Standards (including the MCS 020(a) noise calculation), which set requirements for noise levels and placement. This is not optional — it is a condition of permitted development.

3. Noise Limits

This is the condition that catches people out most often. The installation must pass the MCS 020(a) noise calculation, which estimates the sound level at the nearest neighbouring habitable room window or door from the unit's rated sound power, the distance and any shielding.

Because the result depends on the model's sound power and how far it is from neighbours' windows, positioning is critical. Use the manufacturer's published noise data rather than a rule of thumb.

Your installer should carry out the noise assessment as part of the design process. If the assessment fails, you have two options: reposition the unit (or choose a quieter model), or apply for planning permission.

4. Placement Rules

5. Visual Impact

The installation should be sited, so far as practicable, to minimise its effect on the external appearance of the building and its impact on amenity. In practice, this means positioning the unit at the side or rear of the property rather than prominently at the front.

6. Removal Condition

If the heat pump is no longer needed for heating, it must be removed as soon as reasonably practicable. In practice, this condition is rarely enforced, but it does mean you cannot leave a disused unit permanently installed.

When You DO Need Planning Permission

Even though most installations qualify as permitted development, there are several situations where you will need to submit a planning application:

Listed Buildings

If your home is a listed building (Grade I, II*, or II), you will need listed building consent for any external alterations, including installing a heat pump. You may also need planning permission. The key concern is the visual impact of the outdoor unit and any associated pipework on the building's historic character. For more on heat pumps in period homes, see our guide on heat pumps for older houses.

Conservation Areas

If your property is in a conservation area, permitted development rights for heat pumps are more restricted. In conservation areas, the unit must not be installed on a wall or roof that fronts a highway and is visible from the highway. If the only practical location is on a wall or roof facing a road, you will need planning permission.

Some conservation areas have Article 4 directions that remove specific permitted development rights. Check with your local planning authority whether an Article 4 direction applies to your property.

Flats and Maisonettes

Permitted development rights for heat pumps apply to houses, not flats or maisonettes. If you live in a flat, you will need planning permission for an external heat pump unit, in addition to any freeholder permissions required. See our guide on heat pumps for flats for more detail.

If Permitted Development Rights Have Been Removed

In some areas, permitted development rights have been removed entirely or partially through conditions on newer housing developments or through Article 4 directions. Your property deeds or a call to the local planning department will confirm whether your permitted development rights are intact.

If You Cannot Meet the Noise Condition

If the installation cannot pass the MCS 020(a) noise calculation at the nearest neighbour's window — perhaps because your property is very close to the neighbours — you will need planning permission. The planning application will need to include a noise assessment and may require mitigation measures.

For a comprehensive overview of the installation process including planning considerations, see our heat pump installation guide.

Scotland: Different Rules

Scotland has its own permitted development rules for air source heat pumps, set out in the Town and Country Planning (General Permitted Development) (Scotland) Order 1992 (as amended).

The Scottish conditions differ from England's, and England's rules changed on 29 May 2025, so do not assume the English limits apply. Check the current conditions with your local planning authority before you install. Listed buildings and conservation areas carry extra restrictions in Scotland too.

Wales: Its Own Rules

Wales has its own permitted development rules for air source heat pumps, and they did not change when England relaxed its rules on 29 May 2025. The English changes (no boundary distance, larger units, two units on detached houses) do not apply in Wales, so check with your local planning authority in Wales before you install.

Northern Ireland: Slightly Different

Northern Ireland has its own planning system under the Planning Act (Northern Ireland) 2011. Permitted development for heat pumps exists but is defined in The Planning (General Permitted Development) Order (Northern Ireland) 2015. The specific conditions and thresholds differ from England's. Check with your local council's planning department if you are in Northern Ireland.

The Planning Application Process

If you do need planning permission, here is what to expect:

What You Need to Submit

• Application form: Available through the Planning Portal (or equivalent in Scotland, Wales, and Northern Ireland)
• Site plan: Showing the proposed location of the heat pump unit
• Elevations/drawings: Showing the unit's appearance and position on the building
• Noise assessment: Demonstrating the expected noise level at neighbouring properties
• Design and access statement: Explaining why the chosen position is appropriate
• Planning fee: Currently £258 for a householder application in England

Timeline and Approval Rates

Householder planning applications have a statutory determination period of eight weeks. In practice, straightforward heat pump applications are often decided within six weeks. Planning applications for domestic heat pumps have very high approval rates — well over 90% in most local authority areas. The most common reason for refusal is noise impact on neighbours.

Practical Tips for Staying Within Permitted Development

Most homeowners can avoid the planning process entirely by following these tips:

• Position the unit at the side or rear of the house: This avoids the "fronting a highway" restriction and usually makes the noise condition easier to meet
• Check the distance to your neighbour's nearest window: Use the manufacturer's noise data and the inverse square law to estimate the noise level at that point
• Choose a quieter unit: There is significant variation in noise levels between models. If your property has tight boundaries, prioritise a low-noise model (compare manufacturers' published sound power data)
• Use acoustic barriers if needed: A purpose-built acoustic fence or enclosure can reduce noise at the neighbour's window, which may help the installation pass the noise assessment

For more on where to position your heat pump, see our guide on the best position for an air source heat pump.

What About Ground Source Heat Pumps?

Ground source heat pumps have their own permitted development rules. Horizontal ground loops (buried in trenches) are generally permitted development, as the work is underground and has no visible impact. Vertical boreholes may require planning permission in some circumstances, particularly if the drilling equipment or access arrangements affect highways or neighbours.

Building Regulations

Regardless of whether you need planning permission, all heat pump installations must comply with Building Regulations. This covers the electrical installation, the heating system design, and energy efficiency. Your MCS-certified installer will handle Building Regulations compliance as part of the installation — you should not need to make a separate Building Regulations application.

For a complete overview of the full installation process, read our heat pump installation guide. Homeowners interested in combining renewable technologies should also consider how solar panels can complement a heat pump system — solar installations have their own permitted development rules, and your installer can advise on both.

Frequently Asked Questions

Do I need planning permission for an air source heat pump?

In most cases, no. Air source heat pumps are usually permitted development, provided you meet the conditions on noise, placement, size and number of units. The rules differ between England, Wales and Scotland. You will need planning permission if your home is listed, if you cannot meet the noise limits, or if your permitted development rights have been removed.

What noise condition applies to a heat pump?

To be permitted development in England, the installation must comply with the MCS Planning Standards, which means passing the MCS 020(a) noise calculation for the nearest neighbouring habitable room window or door. Your installer should carry out this assessment before installation.

Can I put a heat pump on the front of my house?

Under permitted development, no — the unit must not be on a wall or roof that fronts a highway. You could apply for planning permission to do this, but approval is unlikely as it would affect the streetscape. Side and rear positions are strongly preferred.

Do I need planning permission in a conservation area?

Not necessarily, but the rules are stricter. In a conservation area, the unit must not be on a wall or roof facing a highway if it would be visible from the highway. If the only practical position is road-facing, you will need planning permission. Check whether any Article 4 directions apply to your property.

How close to my boundary can I put the heat pump?

In England, the old rule that the unit had to be at least 1 metre from the property boundary was removed on 29 May 2025 (SI 2025/560), so there is no longer a minimum boundary distance under permitted development. The unit must still pass the MCS 020(a) noise assessment, which in practice keeps it away from neighbours' windows. Wales and Scotland have their own rules: check with your local planning authority.

Does my installer handle the planning side?

A good MCS-certified installer will check whether your installation qualifies as permitted development and carry out the noise assessment. If planning permission is needed, they may help with the application or recommend a planning consultant. Always confirm what is included in their quote.