Will my heat pump keep the neighbours awake at night?

No, not if it's installed correctly. UK permitted development rules cap noise at 42dB at the neighbour's nearest window, which is quieter than a normal conversation. Most modern units run well below that threshold when properly positioned.

Do I need planning permission for a heat pump because of noise?

Usually no. Heat pumps fall under permitted development in England as long as the MCS 020 noise assessment shows the unit produces no more than 42dB at the nearest neighbour's window, the unit is no larger than 0.6 cubic metres, and it sits more than one metre from the property boundary. Your installer should run this calculation as part of the design. If your site fails the test, you'd need to apply for planning permission, but that's relatively rare for typical installations.

Are heat pumps louder in winter?

Yes. On the coldest nights the fan and compressor work harder to extract heat from cold air, so the unit will be noticeably louder than on a mild day.

What's the quietest heat pump on the market in 2026?

Mitsubishi Ecodan, Daikin Altherma 3, and Vaillant aroTHERM Plus all sit at the quiet end, typically 40 to 48dB at one metre on their mid-sized models. Ground source units from Kensa and Nibe are quieter still because the compressor is indoors. The exact "quietest" varies year to year as manufacturers release new models, so ask your installer for the current sound power data on whatever they're quoting.

Can I put my heat pump in the loft to reduce noise?

Air source units need to be outdoors because they pull heat from outside air. Ground source units can sit indoors, including in a loft or utility room, though most installers prefer ground floor placement for easier maintenance access.

Does an acoustic fence around a heat pump actually work?

Yes, a properly designed acoustic fence can reduce perceived noise at the boundary by 5 to 10 decibels. The key is that it must be slatted or angled to allow airflow to the unit. A solid enclosure will choke the heat pump and damage its performance, so avoid generic garden fencing as an acoustic barrier.

Are Heat Pumps Noisy in 2026? What to Expect

Are Heat Pumps Noisy in 2026? What to Expect | Eco Home Check

How Much Noise Does a Heat Pump Actually Make?

Most modern air source heat pumps measure between 40 and 60 decibels at one metre from the unit. For context, a quiet library sits around 30dB, a fridge runs at about 40dB, and normal conversation hovers near 60dB.

So we're talking fridge-level noise from a metre away.

The number drops fast as you move away. By the time you're standing five metres from the unit, you're typically at 30 to 40dB. At ten metres, most people can't pick it out from background noise unless they're actively listening for it.

Now, manufacturer specs and real-world performance aren't always the same thing. A Daikin Altherma 3 or a Mitsubishi Ecodan running at part-load on a mild October morning is genuinely quiet, you can stand next to it and have a conversation. The same unit working flat-out on a minus-five January night will be noticeably louder, because the fan ramps up and the compressor cycles harder.

This is the honest bit most installer brochures skip. Heat pumps aren't silent. They're a piece of mechanical kit with a fan and a compressor, and on the coldest nights of the year they will be working hardest. See our guide on how heat pumps operate for more detail. But "working hardest" still means quieter than the central heating boiler your gran had in the kitchen.

Ground source units, which we'll get to shortly, are even quieter because the noisy bit lives indoors and the ground loop itself is silent. See our guide on ground source heat pumps for more detail.

Air Source vs Ground Source: Which Is Quieter?

Ground source heat pumps are quieter because the only moving parts are inside the house, usually tucked into a utility room or garage.

With an air source unit, you've got an outdoor fan pulling air across a heat exchanger. That fan is the main noise source. The compressor adds a low hum underneath. Both live outside, usually mounted against an exterior wall or on a small concrete pad.

Ground source flips this. The pipework, the bit collecting heat from the soil, sits underground and makes no sound at all. The compressor and circulation pump are indoors in an insulated cabinet. You'll hear something if you stand next to the unit, similar to a fridge, but neighbours hear nothing.

Here's how the typical noise figures compare:

Heat pump type	Noise at 1m (outdoor)	Noise at 1m (indoor)
Air source (modern, 2024+)	40–55 dB	n/a (outdoor only)
Air source (older, pre-2018)	55–65 dB	n/a
Ground source	n/a	35–45 dB
Air-to-air (split system)	45–55 dB outdoor, 25–35 dB indoor	indoor unit very quiet

The trade-off is cost. A ground source install runs £20,000 to £35,000 because you're digging trenches or sinking boreholes. Air source comes in at £8,000 to £14,000 before the £7,500 Boiler Upgrade Scheme grant. Most UK homeowners go air source for the maths, not because it's quieter. See our guide on air source comes in at £8,000 to £14,000 for more detail. We've broken down the full cost picture for heat pumps in 2026 separately if you want the numbers.

If you've got room and budget for ground source, noise is genuinely a non-issue. For everyone else, it's about getting the air source installation right.

Where You Place Your Heat Pump Makes a Big Difference

Placement matters more than the unit itself. A quiet heat pump installed badly will annoy you. A slightly louder unit positioned well will fade into the background.

The worst spots are obvious once you think about them. Directly under a bedroom window. Tucked into a narrow alleyway between two houses where the sound bounces. Hard up against a fence that vibrates sympathetically. Pointing straight at the neighbour's patio.

Good installers walk the site before quoting. They'll look for a position where the fan exhaust isn't aimed at a habitable window, where there's clearance for airflow (most manufacturers want 30cm minimum at the back and 1m at the front), and where vibration won't transmit through a shared wall.

The best spots tend to be:

On an exterior wall away from bedrooms and away from the boundary line
On a dedicated concrete pad with anti-vibration mounts, set back from any fences
Tucked behind a small garden wall or planting that provides acoustic absorption without restricting airflow

A lazy installer will mount the unit wherever the pipework is easiest. A good one will give you two or three placement options and explain the noise implications of each. If your installer doesn't volunteer this conversation, ask them directly. The heat pump quote you accept should specify the position clearly.

One practical tip we hear from MCS installers regularly: avoid corner positions where two walls meet at 90 degrees. Sound reflects between the two surfaces and amplifies, sometimes by 3 to 6dB. Doesn't sound like much, but 3dB is a doubling of perceived loudness in acoustic terms.

What the Neighbours Think: Permitted Development Rules

In England, air source heat pumps installed under permitted development must not exceed 42dB at the nearest neighbour's window.

This is the MCS 020 planning standard, and it's the rule that determines whether you can install without applying for full planning permission. Your installer should run an MCS 020 noise calculation as part of the design. If they don't, they haven't done their job.

The 42dB figure is measured at one metre from the centre of the nearest window of a neighbouring habitable room, with the unit running at maximum output. In practice, this means most modern units installed at a sensible distance from the boundary will pass easily.

Where it gets tricky is terraced houses, end-of-terrace situations with the unit on the gable wall, or small urban gardens where the neighbour's window is genuinely close. In those cases, the calculation can fail, and you've got three options: choose a quieter unit, move the position, or apply for full planning permission with an acoustic assessment.

Scotland, Wales and Northern Ireland have slightly different permitted development rules. The 42dB threshold applies in England specifically. In Scotland the rules were updated in 2023 to be more permissive on size and position.

A quick aside: from the conversations we've had with installers in dense urban areas like inner London and Brighton, the MCS 020 calculation is the single biggest reason heat pump installs get redesigned or delayed. It's not usually a dealbreaker, but it does sometimes mean a more expensive low-noise unit. Anyway.

How to Reduce Heat Pump Noise in Your Home

You don't need to live with a noisy heat pump. There are practical fixes if yours is louder than you'd like.

Anti-vibration mounts. These are rubber or spring isolators between the unit and its base. Most modern installs include them, but older installations often don't. Retrofitting a set costs £80 to £200 and can knock 3 to 5dB off the perceived noise transmitted through the structure.

Acoustic enclosures. Purpose-built fences or partial enclosures designed for heat pumps, slatted to allow airflow but absorbent enough to dampen sound. A good acoustic fence costs £400 to £900 installed and can reduce noise at the neighbour's boundary by 5 to 10dB. Don't use a solid enclosure, you'll choke the unit and damage performance.

Schedule control. Most modern heat pumps let you set a quiet mode or eco mode at night. The compressor runs at lower speed and the fan slows down. You lose a bit of output, but on a mild night that's fine. On the genuinely cold nights, you probably want full performance anyway.

Upgrade the unit. If you've got an older heat pump (pre-2018) and the noise genuinely bothers you, replacement might be worth it. Modern inverter-driven units from Mitsubishi, Daikin, Vaillant and Samsung run substantially quieter than the first wave of UK installations. The newest air source heat pumps come in around 40 to 48dB at one metre.

Check the airflow path. Sometimes noise increases over time because debris has built up around the unit, restricting airflow and making the fan work harder. Clear leaves, prune shrubs back to maintain clearance, and check the heat exchanger fins for dirt.

The honest position: most noise complaints we hear about traced back to bad installation, not bad units. Get the placement right at the start and you almost never need to retrofit anything.

Grants Available in 2026 to Help Cover the Cost

The Boiler Upgrade Scheme gives you £7,500 off an air source or ground source heat pump in England and Wales, and runs until March 2030.

This is the main scheme most homeowners use. You need an EPC with no outstanding insulation recommendations (loft and cavity wall must be done, or have a valid exemption), and the installer must be MCS certified. The grant is paid to the installer, who deducts it from your quote.

For benefits-eligible households, ECO4 can fund a heat pump in full where it replaces an inefficient electric or solid fuel heating system. The criteria are stricter, it's targeted at the lowest-income homes with the worst EPC ratings, but where it applies, you pay nothing. ECO4 runs to December 2026, so the window is tightening. We've covered ECO4 eligibility in detail separately.

The Warm Homes: Local Grant is the third route. Amounts vary by council, and so does what's funded, some authorities prioritise insulation, others include heat pumps. Worth checking with your local authority directly.

For air-to-air heat pumps (the type that heats your home like air conditioning rather than via radiators), the BUS grant is £2,500 since April 2026. That's a recent expansion, before then air-to-air wasn't covered at all.

If you're not sure which scheme applies to your situation, the eligibility checker runs your postcode and benefits status against all three in about two minutes.

One thing worth knowing: the BUS grant doesn't have a fixed annual budget cap in the way some grants do. The Treasury extended funding through to 2030 in the spring 2024 announcement. So unlike GBIS, which closed in March 2026, BUS isn't going to disappear in the next year or two.

Common questions

Frequently asked questions

Will my heat pump keep the neighbours awake at night?: No, not if it's installed correctly. UK permitted development rules cap noise at 42dB at the neighbour's nearest window, which is quieter than a normal conversation. Most modern units run well below that threshold when properly positioned.
Do I need planning permission for a heat pump because of noise?: Usually no. Heat pumps fall under permitted development in England as long as the MCS 020 noise assessment shows the unit produces no more than 42dB at the nearest neighbour's window, the unit is no larger than 0.6 cubic metres, and it sits more than one metre from the property boundary. Your installer should run this calculation as part of the design. If your site fails the test, you'd need to apply for planning permission, but that's relatively rare for typical installations.
Are heat pumps louder in winter?: Yes. On the coldest nights the fan and compressor work harder to extract heat from cold air, so the unit will be noticeably louder than on a mild day.
What's the quietest heat pump on the market in 2026?: Mitsubishi Ecodan, Daikin Altherma 3, and Vaillant aroTHERM Plus all sit at the quiet end, typically 40 to 48dB at one metre on their mid-sized models. Ground source units from Kensa and Nibe are quieter still because the compressor is indoors. The exact "quietest" varies year to year as manufacturers release new models, so ask your installer for the current sound power data on whatever they're quoting.
Can I put my heat pump in the loft to reduce noise?: Air source units need to be outdoors because they pull heat from outside air. Ground source units can sit indoors, including in a loft or utility room, though most installers prefer ground floor placement for easier maintenance access.
Does an acoustic fence around a heat pump actually work?: Yes, a properly designed acoustic fence can reduce perceived noise at the boundary by 5 to 10 decibels. The key is that it must be slatted or angled to allow airflow to the unit. A solid enclosure will choke the heat pump and damage its performance, so avoid generic garden fencing as an acoustic barrier.