The Complete Guide to Heat Pumps for Flats

✔ Air source heat pumps can be installed in garden flats or ones with balconies

✔ A block of flats can be connected to a shared ground source heat pump

✔ An air source heat pump’s external unit takes up around 1 square metre

Thinking of installing a heat pump in your flat? With much of the heat pump discussion centred on houses, it can be difficult to know whether it's even possible to install one in a flat, how much a heat pump will cost you, and how you can get one.

We’ll answer these two questions in this article. We’ll also tell you how much a heat pump costs, if it can save you money on your energy bills, and if there are any grants available that can help you install one.

If you want to skip all the details and get in touch with an installer, we can help. Just fill in our short form with a few details, and we’ll pass them on to certified heat pump installers. They’ll reach out to you with their best prices.

Can you install a heat pump in a flat?

Yes, you can install a heat pump in flats, but it can be a complex process.

When installing heat pumps in flats, there are two set-ups to choose between. Flats can have an individual heat pump, where one heat pump provides heating for one flat, or a block of flats can have a shared heat pump system.

In the shared heat pump scenario, one or more main heat pump units are installed outside, and are connected to individual indoor units installed in each flat.

We’ll take a closer look at what type of flats suit each set-up in the following sections.

Individual heat pumps for flats

Individual heat pumps are only possible for flats with some outdoor space – such as a balcony or a garden – since they have somewhere to store the heat pump’s external unit.

Air source heat pumps are the only option for flats with a balcony but no garden. But the balcony would need to be larger than 1 square metre – the size of the average outdoor unit for an air source heat pump.

Most flats with gardens will also have to get an air source heat pump, since it’s unlikely they’ll have the 100 square metre garden they require for a ground source heat pump. Installing an air source heat pump also costs at least £10,000 less than installing a ground source one.

If a flat doesn’t have a balcony or a garden, the air source heat pump’s outdoor unit could potentially be attached to the outside wall of the flat, in a similar way to an air conditioning unit.

But it would need to be somewhere with easy access – from the window or the ground – for when maintenance work needs to be carried out.

There's also the options of using a portable heat pump. These are plug-in models that can heat or cool a single room.

Shared heat pumps for blocks of flats

A large, shared heat pump can heat a whole block of flats, and it's pretty much the only option for highrises, or blocks of flats with no balconies or garden.

This is usually done with ground source heat pumps. A shared ground loop – the portion of the ground source heat pump that draws heat from the earth – is trenched in the ground near the block of flats, and connected to individual indoor units installed inside each flat.

A large main air source heat pump could also be installed on the roof, and be connected to individual units in the flats. Heat pump manufacturer Daikin has recently come up with this kind of shared solution for new-build high rise apartment blocks.

How do you get a heat pump for your flat?

If you want to get a shared heat pump for a block of flats, you need to ask the freehold owner, unless you own the whole building. That means approaching the person or corporation who owns the property and the land it's built on.

Since the technology for doing this has only been rolled out in the past few years, there aren’t currently many installers who are qualified to install a shared heat pump system in a block of flats, so your options might be limited.

For example, Vaillant – one of the largest heating technology developers in Europe – only just showcased its first heat pumps designed specifically for flats in March 2023.

One company that has installed shared ground source heat pumps in flats is Kensa. So far though, Kensa’s services are only available for new-build apartments, or existing social housing – in most cases to replace outdated storage heaters.

To install an individual air source heat pump in a flat with a balcony or garden, you’ll need to first make sure you have the right to do so. If you’re renting, you’ll need the landlord or freeholder’s consent before you install a heat pump. If you only own a share of the freehold, you might need the other freeholders' consent.

How much does a heat pump cost for a flat?

An air source heat pump for a flat costs around £7,000 to buy and install. A ground source heat pump costs around £17,000.

That’s not including the cost of other measures to make a flat heat pump-ready, such as installing bigger radiators, better insulation, and/or underfloor heating. We’d usually recommend these extra measures to ensure your home feels comfortably warm, since heat pumps produce heat at lower temperatures than boilers.

The cost of a shared heat pump system for a block of flats will vary drastically depending on the size of the block, how many flats are in it, and the complexity of the installation.

For example, Enfield Council in London recently spent £7.3 million to retrofit 13 high-rise apartment blocks, accounting for around 400 flats, with a shared ground source heat pump. That’s around £18,250 per flat, so not much more than installing a ground source heat pump for an individual household.

If you want to find out more about how much a heat pump costs, head to our full guide.

Will a heat pump help you save on energy bills in a flat?

A heat pump won’t save you money on your energy bills in the short term, if you’re switching to one from a gas boiler. But it could save you money over time.

Gas is currently cheaper than electricity – which heat pumps run on – so if you're switching from a gas boiler to a heat pump, your energy bills will be slightly higher.

In the future, the price of gas is expected to rise, whilst the price of electricity is expected to go down. As the government pushes for more people to switch away from fossil fuels such as gas and oil, they’re likely to make electricity the cheapest way to heat homes.

Are there any government grants for heat pumps in flats?

There are four government grants for individual heat pumps in flats: the Boiler Upgrade Scheme, ECO4, Warmer Homes Scotland, and Nest Wales.

These grants aren’t created specifically for flats, but there’s no stipulation in them that people living in flats can’t use them, as long as they meet the eligibility requirements.

You can see a summary of the available schemes for individual heat pumps in flats in the following table. If you want to know more about each scheme, head to our page on heat pump grants.

There are currently no active grants for shared heat pump systems in blocks of flats. But there have been a few funding projects for local authorities in the past, such as the Social Housing Decarbonisation Fund (SHDF), and the Sustainable Warmth Competition.

Both these schemes are now closed to applications, but it’s highly likely the government will open more in the coming months or years.

Case studies: High rise apartments in Thurrock

Three tower-blocks, containing 273 flats, were retrofitted with shared ground source heat pumps between 2022 and 2023. The outdated storage heaters in the flats were replaced with individual indoor heat pump units, connected to a shared ground loop.

The project was a collaboration between Thurrock Council in Essex, which owns the tower-blocks, and ground source heat pump installers Kensa. It was funded in part by the government’s Social Housing Decarbonisation Fund, which awarded Thurrock Council £3.2 million for the installation.

Residents of the flats have reported that the new system is better at keeping their homes warm. And according to Kensa Contracting, replacing the energy inefficient storage heaters with a ground source heat pump could help residents in a two-bedroom flat save around £952 a year on their energy bills.

Next steps

It might be trickier in some cases to install heat pumps in flats compared to houses, but not because flats are poorly suited to them.

In fact, a 2020 government-funded project called The Electrification of Heat found that all properties are suitable for a heat pump. The project was designed to test heat pumps in different types of homes, and they were successfully able to install heat pumps in everything from flats to Victorian houses.

If you want to find out if your flat is suitable for an individual heat pump, we can help. Just pop a few details into our form, and we’ll pass them on to professional heat pump installers. They’ll reach out to you with quotes and their expert advice.

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