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Complete Cost & Installation Guide

Air Source Heat Pumps: Cost, Grants & What to Expect

Air source heat pump cost in England typically runs £8,000–£15,000 installed before any grant, with a standard 3-bed semi usually sitting around £8,000–£14,000. The £7,500 Boiler Upgrade Scheme (BUS) grant is deducted directly from the bill, bringing most homes down to roughly £500–£7,500 out of pocket. Solar Xtra handles the survey, design, grant paperwork, and installation as one fully managed process.

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£8k–£15kGross Before Grant
£7,500BUS Grant
£500–£7.5kTypical Net Cost
Professional Installation
Air source heat pump installed outside a UK home
3-Bed Semi (Most Common)
Gross Cost£8,000–£14,000
After £7,500 BUS Grant£500–£6,500
The Basics

What Is an Air Source Heat Pump?

An air source heat pump (ASHP) extracts heat from the outside air and uses it to warm your home and hot water, replacing a gas, oil, or LPG boiler with a lower-carbon system. Unlike a boiler, which burns fuel to generate heat instantly, a heat pump runs continuously at a lower, steadier output — which is why correct sizing and insulation matter more than with a traditional boiler.

Coefficient of Performance (COP)
1 UnitElectricity In
3–4 UnitsHeat Delivered
3–4 COPWell-Installed System
Air source heat pump outdoor unit
Pricing Breakdown

How Much Does an Air Source Heat Pump Cost?

Cost depends mainly on property size, insulation level, and whether radiator or hot water cylinder upgrades are needed alongside the unit itself.

1–2 Bed Flat/Terrace
5–6 kW unit
Gross Cost£7,000–£10,500
After BUS Grant£0–£3,000
Most Common
3-Bed Semi
8–10 kW unit
Gross Cost£8,000–£14,000
After BUS Grant£500–£6,500
4-Bed Detached
10–14 kW unit
Gross Cost£12,000–£18,000
After BUS Grant£4,500–£10,500

Figures reflect current UK market averages (2026) and are for guidance only — your exact air source heat pump cost is confirmed after a heat-loss survey, not a size-by-bedroom table.

What's Included in the Price

Outdoor Heat Pump Unit

The single largest cost, varying by manufacturer and output.

Hot Water Cylinder

Usually 180–300L, sized to household hot water demand.

Heat-Loss Survey & System Design

Required to properly size the heat pump system and support the BUS grant application.

Radiator Upgrades

Heat pumps run at lower flow temperatures, so some radiators may need enlarging.

Electrical Works

A new dedicated circuit is commonly required.

Commissioning & Certification

Ensures the system is properly tested, documented, and ready for use, while supporting any applicable grant and workmanship warranty requirements.

Government Funding

The Boiler Upgrade Scheme Grant Explained

£7,500
Flat Grant — Deducted Directly From Your Invoice

Applied for by your installer and deducted directly from the invoice, so you never handle the grant money yourself.

Must replace an existing fossil-fuel heating system
Hybrid systems combining a heat pump with a gas boiler are not eligible
Applied for on your behalf by your installer
Scheme currently funded through to March 2028 — eligibility rules reviewed periodically
Running Costs

Cheaper to Run Than a Gas Boiler?

Usually, Yes.

In a well-insulated home on a heat-pump-friendly tariff, running costs typically come in lower than a modern gas boiler. In a poorly insulated home with high flow temperatures, however, a heat pump can end up more expensive to run, which is why a proper heat-loss survey is essential before installation.

Typical Annual Saving vs a Modern Gas Boiler
£150–£400Per Year, Well-Insulated Home
This gap depends on the wider gas-versus-electricity price relationship, which shifts with each seasonal price cap change — a single "always cheaper" claim isn't reliable without checking current rates.
Correct Sizing

What Size Heat Pump Do You Need?

Heat pump sizing is based on your property's heat loss, not simply the number of bedrooms — a well-insulated 3-bed home may need a smaller unit than a poorly insulated 2-bed.

5–6 kW
1–2 Bed Home
Typical starting point
8–10 kW
3-Bed Semi
Most common size
10–14 kW+
4-Bed Detached
Larger properties
Oversizing wastes money and can cause inefficient cycling; undersizing leaves the home under-heated. Both are reasons the heat-loss survey exists before any quote is finalised.
Radiator upgrade for heat pump compatibility
Getting Your Home Ready

Do You Need to Upgrade Your Radiators or Insulation?

Because heat pumps run at lower flow temperatures than a gas boiler, some — though rarely all — radiators may need to be enlarged to release the same amount of heat into a room. Loft and cavity wall insulation also has a bigger impact on a heat pump's running efficiency than it does on a boiler's, since the unit is designed to run steadily rather than in short bursts.

Some radiators may need enlarging — rarely all of them
Loft and cavity wall insulation matter more than with a boiler
Heat-loss survey identifies exactly what needs upgrading
No assumption of a whole-house repipe
System Types

Monobloc vs Split Systems

The two main configurations for an air source heat pump — here's how they compare.

Standard for UK Retrofits

Monobloc

Houses all the refrigerant components in a single outdoor unit, making it the most common choice for UK retrofits and generally simpler to install.

Specialist Install

Split System

Separates the components between an indoor and outdoor unit, connected by refrigerant pipework, and requires a specialist F-Gas registered engineer — typically adding to the overall cost.

For most UK homes, a monobloc system is the standard recommendation unless a specific property layout calls for a split setup.
Regulations

Do You Need Planning Permission?

Usually No.

Air source heat pumps fall under Permitted Development in England and Wales, provided a few key distance and property rules are met. Listed buildings, flats, and conservation areas typically still require full planning permission — this is checked as part of your survey rather than assumed.

Permitted Development Rules
Unit sited at least 1 metre from the property boundary
Not closer than 1 metre to a window
Property isn't listed or in a conservation area
1-metre boundary rule relaxed in England from May 2025 for compliant low-noise units
FAQs

Frequently Asked Questions

Quick answers to the questions we hear most about air source heat pumps.

How much does an air source heat pump cost in the UK?

Most homes pay £8,000–£15,000 gross before any grant, with the £7,500 BUS grant bringing typical out-of-pocket cost down to roughly £500–£10,500 depending on property size.

How does the £7,500 Boiler Upgrade Scheme grant work?

Your installer applies on your behalf and deducts the grant directly from the invoice, so you don't receive or handle the money yourself, and hybrid systems don't qualify.

Is an air source heat pump cheaper to run than a gas boiler?

Usually, in a well-insulated home on a heat-pump-friendly tariff, though a poorly insulated property with high flow temperatures can see higher running costs — which is why a heat-loss survey comes before any quote.

Will an air source heat pump work in my home?

Most UK homes are suitable, but suitability depends on insulation level, radiator sizing, and outdoor space for the unit — confirmed through a heat-loss survey rather than assumed from property type alone.

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

In most cases, no — units fall under Permitted Development provided boundary and window-distance rules are met, though listed buildings and conservation areas usually need full permission.

How long does installation take?

A typical installation takes 3–5 days on site once the heat-loss survey and design are complete, with the full process from enquiry to commissioning usually spanning several weeks.

What's the difference between monobloc and split systems?

Monobloc systems keep all components in a single outdoor unit and are the standard choice for most UK retrofits; split systems need a specialist F-Gas engineer and typically cost more to install.

Still have questions?

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Free Heat-Loss Survey

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Find out your exact air source heat pump cost, after the BUS grant, with a free heat-loss survey from Solar Xtra's experienced team.

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