Renewable Energy
Air Source Heat Pump Planning Permission: What You Need to Know (2025)
Air source heat pumps gained permitted development rights in England in 2012. Most domestic installations don’t need planning permission — but noise limits, exclusion zones, and conservation area rules all apply.
⏱ 5 min read
📅 Updated June 2025
🏠 England only
Quick Answer
For most houses: No planning permission needed
Air source heat pumps (ASHPs) are permitted development under Class G of Part 14, Schedule 2 to the GPDO 2015. This means planning permission is not normally required for an ASHP installed on a house in England, provided the installation meets the noise limit (42 decibels at one metre from a neighbour’s window or door), the unit is not on the roof, and is not the second unit on the property. Listed buildings, conservation areas, and some flats are exceptions.
Permitted Development Conditions for ASHPs
For an air source heat pump installation to be permitted development, all of the following must be satisfied:
- The installation is on a house (not a flat, though see below)
- The unit is not installed on a roof
- The unit is not installed on a wall or roof if the property is within a conservation area or World Heritage Site and the unit would be visible from the highway
- The unit’s noise level does not exceed 42 decibels at one metre from the nearest window or door of a neighbouring property
- The unit is at least one metre from the property boundary
- It is the only air source heat pump on the property
- When no longer needed, the unit is removed
✅ The MCS scheme handles planning confirmation automatically
If your installer is MCS-certified and the installation follows MCS 020 (the heat pump standard), the installation is automatically treated as meeting the noise condition. Most reputable installers are MCS-certified, so this is rarely an issue in practice.
The Noise Limit Explained
The 42 decibel limit is measured at one metre from the nearest window or door of a neighbouring property — not your own. This is an important distinction. An ASHP that makes 50dB at your own back door may still be permitted development if it’s far enough from your neighbours’ windows.
Modern ASHPs typically operate at 40–55 dB at one metre from the unit. Whether they meet the 42dB limit at a neighbour’s window depends on:
- The noise output of the specific unit model
- The distance from the unit to the neighbour’s nearest window or door
- Any screening (fences, walls) between the unit and the neighbour
A qualified ASHP installer should assess whether your proposed installation location meets the 42dB limit as part of the survey. This assessment should be documented.
⚠️ If the noise limit can’t be met, planning permission is required
If the only viable location for the unit would cause more than 42dB at a neighbour’s window, the installation is not permitted development and requires a planning application. The planning application would need to address the noise impact.
Location Rules
Key location requirements under the permitted development rules:
| Requirement |
Detail |
| Not on a roof |
ASHPs must be mounted at ground level, on a wall, or on a stand. Roof-mounted ASHPs always need planning permission |
| Minimum 1m from boundary |
The unit must be at least one metre from any property boundary |
| One unit only |
Only one ASHP per property under PD — a second unit always needs permission |
| Conservation areas |
If visible from highway in a conservation area, not permitted development |
Wall-mounted ASHPs (mounted on the side or rear wall of the house) are permitted development provided they meet all the conditions above. Wall mounting is common for smaller units and can help with the 1m boundary requirement.
When You Need Planning Permission
- Roof-mounted units: Always need planning permission
- Second ASHP on the same property: Always needs planning permission
- Noise limit not met: If the installation would exceed 42dB at a neighbour’s window
- Listed buildings: Any installation requires planning permission and potentially listed building consent
- Conservation areas (visible from highway): Wall or roof installations visible from the road require planning permission
- World Heritage Sites: ASHPs are not permitted development in World Heritage Sites
- Within 1m of boundary: Units closer than 1m to any boundary require planning permission
- Flats (in some cases): PD rights for ASHPs apply to dwellinghouses — flats may not have the same rights depending on the planning history
Conservation Areas and Listed Buildings
In conservation areas, ASHPs are not permitted development if they would be installed on a wall or roof that faces a highway and the unit would be visible from that highway. Units installed in rear gardens, or on walls that don’t face the road, may still be permitted development within conservation areas — provided all other conditions are met.
For listed buildings, any ASHP installation requires planning permission. Listed building consent may also be required if fixing the unit to the fabric of the building would affect its character. An ASHP on a standalone ground stand in the garden of a listed building is less likely to need listed building consent, but always check with the council first.
Building Regulations
ASHP installations are subject to Building Regulations — specifically Part L (conservation of fuel and power) and Part P (electrical safety). In practice, MCS-certified installers handle all Building Regulations compliance as part of the installation. Using an MCS-certified installer is also required to access the Boiler Upgrade Scheme (BUS) grant, which provides up to £7,500 off the cost of an ASHP.
A separate planning application and Building Regulations notice are different processes — even if your ASHP is permitted development, Building Regulations still apply.
Frequently Asked Questions
Do air source heat pumps need planning permission?
In most cases, no. Air source heat pumps are permitted development in England under Class G of Part 14 GPDO 2015. The key conditions are: the unit is not on a roof, it meets the 42dB noise limit at a neighbour’s window, it is at least 1 metre from the property boundary, and it is the only ASHP on the property. Listed buildings, some conservation areas, and roof-mounted units always need planning permission.
Can I put an air source heat pump in a conservation area?
Possibly. In a conservation area, ASHPs are not permitted development if they’re on a wall or roof visible from a highway. However, units in a rear garden or on a wall that doesn’t face the road may still be permitted development in a conservation area, provided all other conditions are met. Always check with your local planning authority before proceeding in a conservation area.
How loud are air source heat pumps and will they disturb neighbours?
Modern ASHPs typically operate at 40–55 dB at one metre from the unit — similar to a quiet dishwasher or conversation. The planning rules require the noise level to not exceed 42 dB at one metre from a neighbour’s nearest window or door. Whether this is met depends on the distance from the unit to neighbouring windows and any barriers between them. A qualified MCS installer will assess this as part of the installation survey.
Can I get a grant for an air source heat pump?
Yes. The Boiler Upgrade Scheme (BUS) offers grants of up to £7,500 towards the cost of an air source heat pump. To qualify, you must use an MCS-certified installer, have a valid EPC (Energy Performance Certificate), and the installation must meet the scheme’s eligibility criteria. The grant is applied by the installer at the point of installation — you don’t claim it separately.
More on Permitted Development Rights
Solar panels, extensions, outbuildings, loft conversions — our complete guide covers everything you can do without planning permission.
Read the Complete PD Guide →
