A Homeowner's Guide to Air Source Heat Pumps (ASHPs) in the UK

Note: As our content contains many acronyms, we've made a useful resource.

Relevant Acronyms

A Greener Way to Heat Your Home

The UK is committed to achieving Net Zero greenhouse gas emissions by 2050, a target that necessitates significant changes across the economy, particularly in how homes are heated.1 Domestic heating is a major contributor to the nation's carbon footprint 3, and transitioning away from fossil fuels like gas and oil is essential. Alongside environmental drivers, rising and volatile fossil fuel costs, coupled with energy security concerns, are prompting homeowners to seek more sustainable and potentially cheaper heating alternatives.2

Air Source Heat Pumps (ASHPs) represent a key technology in this shift towards decarbonised heating.1 An ASHP is a low-carbon heating system that efficiently extracts heat from the outside air to warm homes and provide hot water. Recognising their importance, the UK government actively supports their adoption through various initiatives and financial incentives.5 The push towards technologies like ASHPs is driven by multiple factors: environmental necessity (meeting climate targets), national energy security (reducing reliance on imported gas), and household economics (offering potential long-term protection against fossil fuel price shocks).2

This guide aims to provide UK homeowners with a clear, balanced, and comprehensive guide to ASHPs. It will cover how they function, explore the advantages and potential drawbacks, detail the costs involved, outline available financial support, and discuss practical installation considerations. The goal is to equip homeowners with the necessary information to make an informed decision about whether an ASHP is the right choice for their property, understanding that adopting such technology aligns with a clear national policy direction towards cleaner heating.1

How Do Air Source Heat Pumps Work?

The Basic Principle

An Air Source Heat Pump, specifically the air-to-water type common in UK homes, operates on a principle similar to that of a refrigerator, but in reverse.5 Instead of removing heat from inside a fridge and expelling it, an ASHP extracts latent heat energy present in the outside air – even when temperatures are below freezing – and transfers it into the home.6 This ability to draw heat from seemingly cold air can appear counterintuitive. It relies on the physical properties of a special refrigerant fluid within the heat pump, which has a very low boiling point.10 Even air that feels cold contains thermal energy, and this energy is sufficient to cause the refrigerant to boil and turn into a gas, initiating the heat transfer cycle. Understanding this mechanism helps demystify the technology and builds confidence in its viability, especially regarding performance during colder months.

Key Components & Process

The process involves several key components and stages:

1. Evaporation: An outdoor unit containing a fan draws ambient air across a heat exchanger (the evaporator). The heat from the air, even if minimal, causes the cold liquid refrigerant inside the evaporator coil to absorb energy and turn into a gas.8

2. Compression: This refrigerant gas is then passed through an electric compressor. Compressing the gas significantly increases its temperature.5

3. Condensation: The hot, high-pressure refrigerant gas moves to a second heat exchanger (the condenser). Here, it releases its heat into the water circulating through the home's central heating system (radiators or underfloor heating) and/or a hot water cylinder. As it releases heat, the refrigerant condenses back into a high-pressure liquid.6

4. Expansion: The high-pressure liquid refrigerant passes through an expansion valve, which reduces its pressure and temperature rapidly, returning it to a cold liquid state, ready to start the cycle again.8

This continuous cycle efficiently transfers heat from the outside air to the home's heating and hot water systems.6

Efficiency Explained (COP & SCOP)

A crucial aspect of ASHPs is their high energy efficiency, typically measured using two key metrics:

• Coefficient of Performance (COP): This measures the ratio of heat output to the electrical energy input required to run the pump at a specific outdoor temperature.11 For example, a COP of 3 means that for every 1 kilowatt-hour (kWh) of electricity consumed by the heat pump, 3 kWh of heat energy is delivered to the home.12 Typical COP values for ASHPs range from 2 to 4, depending on the conditions.11 While useful, COP provides only a snapshot of performance.

• Seasonal Coefficient of Performance (SCOP): This provides a more realistic measure of a heat pump's efficiency over an entire heating season, averaging performance across varying outdoor temperatures.10 SCOP gives homeowners a better indication of the system's likely year-round efficiency in the UK climate. A good SCOP is generally considered to be above 3.5 12, with some models achieving SCOPs over 4.5 under standard test conditions.13

This high efficiency (often cited as 300% or more) is what distinguishes ASHPs from traditional boilers, which typically operate at around 90% efficiency.5 It's important to recognise that efficiency is not constant; SCOP reflects an average performance influenced by factors like outdoor temperature, system design, and home insulation, which helps manage homeowner expectations about real-world operation.4

The Advantages of Installing an ASHP

ASHPs offer several compelling benefits for UK homeowners considering a move away from fossil fuel heating systems.

• High Energy Efficiency: As outlined previously, ASHPs are significantly more efficient than conventional heating systems. Delivering typically 3 to 4 units of heat for every unit of electricity consumed (SCOP > 3.5), they represent a major improvement over even the most efficient A-rated gas boilers (~90% efficiency).5

• Potential for Lower Running Costs: The high efficiency of ASHPs can translate into lower running costs, although this depends on several factors. Despite electricity typically having a higher unit price than gas 14, the efficiency advantage means ASHPs can be cheaper to run, particularly when replacing older, less efficient G-rated gas boilers (potential savings £240-£290/year), oil boilers (£510/year), or LPG boilers (£510/year).15 Savings compared to modern A-rated gas boilers may be smaller or depend on utilising cheaper off-peak electricity via smart tariffs.5 A smart meter is required to access these tariffs.5 For homes currently using oil or LPG, installing an ASHP also eliminates the need for fuel deliveries and associated costs.13 However, the potential for running cost savings is conditional. It relies heavily on the system achieving good real-world efficiency (SCOP), which is influenced by factors like proper installation, adequate home insulation, and correctly sized radiators. It also depends on the prevailing price difference between electricity and gas. Therefore, while savings are possible, they are not guaranteed for every household, especially those replacing modern, efficient gas boilers without optimising their electricity tariff and usage patterns.4

• Reducing Your Carbon Footprint: ASHPs produce zero carbon emissions at the point of use, significantly lowering a household's environmental impact compared to burning fossil fuels.4 Annual carbon savings can be substantial compared to gas (1,900-2,900 kg), oil (2,900-4,400 kg), and LPG (2,200-3,400 kg) boilers.15 This directly supports the UK's Net Zero ambitions.1 As the UK electricity grid continues to decarbonise with more renewable generation, the carbon savings associated with electrically powered heat pumps will further increase over time.5

• Government Financial Support: The Boiler Upgrade Scheme (BUS) offers a substantial grant of £7,500 towards the installation cost of an ASHP in England and Wales, making the technology considerably more accessible.5 (Further details are provided in Section 5).

• Longevity and Maintenance: ASHPs generally have a longer operational lifespan than conventional boilers, often estimated at 20-30 years compared to around 15 years for a boiler.15 Maintenance requirements are typically low, usually involving an annual service check by a qualified engineer.13 The combination of this longer lifespan and the significant upfront grant fundamentally alters the long-term total cost of ownership. Over a 25-30 year period, a homeowner might need to replace a boiler twice, whereas a single ASHP could suffice. When factoring in the BUS grant and potential running cost savings, the overall lifetime cost of an ASHP can compare favourably to the cumulative cost of multiple boiler replacements, even if the initial post-grant investment is higher.7

• Safety and Versatility: ASHPs eliminate the risks associated with combustion, such as carbon monoxide leaks. Additionally, some ASHP systems can be configured to provide cooling during warmer months, offering year-round climate control.8

Important Considerations and Common Concerns

While ASHPs offer significant advantages, homeowners should also be aware of several important considerations and common concerns before making a decision.

• Upfront Investment: The initial cost of purchasing and installing an ASHP system is typically higher than for a conventional gas boiler. Estimates range from £7,000 to £16,000, depending on the system size, property specifics, and required ancillary work.8 The £7,500 Boiler Upgrade Scheme grant significantly mitigates this cost.7 However, homeowners must also budget for potential necessary upgrades to their home's insulation or radiator system to ensure the heat pump operates efficiently, which can add to the overall project cost.4

• Performance in UK Winters: A common concern is whether ASHPs can provide sufficient heat during cold UK winters. Modern ASHPs are designed to operate effectively even in sub-zero temperatures, typically down to -15°C or even -25°C.10 While it's true that their efficiency (COP/SCOP) decreases as the outside air gets colder 11, meaning they consume more electricity to produce the same amount of heat 10, typical UK winter temperatures (averaging 0-7°C 16) are well within their effective operational range.10 Frost can accumulate on the outdoor unit in cold, damp conditions, triggering an automatic 'defrost cycle'. This is a normal function where the unit briefly reverses to melt the ice, consuming some extra energy.11 Keeping the outdoor unit clear of obstructions like leaves or snow drifts ensures optimal airflow and performance.10 The successful widespread use of ASHPs in much colder Scandinavian countries demonstrates their capability in cold climates.10 However, it's crucial to understand that the perceived performance issues in winter are often linked more to inadequate home insulation or undersized radiators rather than the inherent capability of the heat pump itself. These factors impact efficiency year-round but become most noticeable when heat demand is highest.4

• Noise Levels: The outdoor unit of an ASHP contains a fan and compressor, which generate some noise during operation. Homeowners often express concern about potential noise disturbance. However, modern ASHPs are designed to operate quietly, with noise levels often comparable to a standard domestic refrigerator or a modern condensing boiler.5 UK planning regulations for permitted development typically set noise limits to prevent nuisance to neighbours (e.g., 42 decibels measured 1 metre from a neighbour's window).22 Evidence suggests noise complaints related to heat pumps are infrequent.22 Careful placement of the outdoor unit (e.g., away from bedroom windows or neighbouring boundaries) can minimise potential impact. For particularly sensitive locations, acoustic enclosures or barriers can be considered.22 Homeowners seeking the quietest options can look for models certified by Quiet Mark, an independent scheme recognising low-noise appliances.24Table 1: Examples of Quiet Mark Certified ASHP Models (Note: Certification status and models can change; always verify current certification)

Manufacturer	Model Example	Notes	Snippet ID
Vaillant	aroTHERM Plus	Uses natural refrigerant, various outputs	24
NIBE	S2125	Inverter-controlled, natural refrigerant	24
Daikin	Altherma 3 H HT	Single fan, high efficiency	24
Grant	Aerona³ R32 / Aerona 290	R32 or R290 refrigerant options	24
Worcester Bosch	Compress 5800i AW	Designed for UK weather, quietest Bosch model	24
Samsung	EHS Mono HT Quiet	High temp, low noise for renovations	24
LG	THERMA V R290 Monobloc	Natural refrigerant, monobloc design	24
Mitsubishi	Ecodan R290	Operates down to -25°C, R290 refrigerant	24
Ideal Heating	Logic Air	Monobloc, weather compensating controls	10

• Home Suitability - Installation Requirements:

• Insulation: Achieving high levels of home insulation is paramount for ASHP efficiency and homeowner comfort.4 Because ASHPs operate most efficiently at lower water flow temperatures, minimising heat loss through the building fabric (walls, roof, floors, windows, doors) is essential.20 Around 25% of heat can be lost through an uninsulated roof and roughly a third through uninsulated walls.4 While good insulation (e.g., 200mm+ loft insulation, cavity wall fill) is no longer a strict eligibility requirement for the BUS grant 4, it remains highly recommended for optimal system performance and lower running costs.4

• Radiators/Heat Emitters: ASHPs typically deliver heat via water at lower temperatures (around 35-55°C) compared to traditional boilers (60-80°C).8 This lower flow temperature means that existing standard-sized radiators may not provide enough heat output to keep rooms comfortable.8 Therefore, it's often necessary to replace some or all existing radiators with larger ones (which have a greater surface area) or install low-temperature radiators designed specifically for heat pumps.13 Underfloor heating systems are ideally suited to the lower flow temperatures of ASHPs.13 A qualified installer must perform a room-by-room heat loss calculation to determine the appropriate size and type of heat emitters required.21 The relationship between insulation levels, required flow temperature, and radiator size is critical: better insulation reduces the heat demand, potentially allowing lower flow temperatures and/or avoiding the need for extensive radiator upgrades.4

• Space Requirements: An ASHP system requires space for the outdoor unit (typically 1-1.5m high 5), which needs good airflow and should be positioned considering noise regulations.10 Indoors, space may be needed for a hot water cylinder (as ASHPs don't provide instant hot water like combi boilers) and potentially a buffer tank or other control units.5

• Electrical Supply: The home's electrical system must be capable of handling the load of the heat pump. An installer will assess this during the survey.

• Planning Permission: In England, installing an ASHP usually falls under permitted development rights, meaning formal planning permission is not needed, provided specific conditions regarding size, location, and noise output are met.22 However, rules can differ, particularly for listed buildings, properties in conservation areas, or in Wales and Scotland, so it's always wise to check with the local planning authority.22

Financial Help Available: Grants and Support

Navigating the cost of installing an ASHP is made significantly easier by government support schemes. Understanding these is crucial for homeowners.

• Boiler Upgrade Scheme (BUS) - The Primary ASHP Grant:

• Grant Amount: The BUS provides a grant of £7,500 towards the cost and installation of an air source heat pump (ASHP) or ground source heat pump (GSHP).7 A £5,000 grant is available for biomass boilers in specific circumstances.7

• Eligibility: The scheme is open to homeowners and small non-domestic property owners in England and Wales.7 Key requirements include: replacing an existing fossil fuel (gas, oil, LPG) or direct electric heating system; the property must have a valid Energy Performance Certificate (EPC); the installation capacity must not exceed 45kWth (most homes); the property cannot be a new build (except self-builds) or social housing.7

• Insulation Requirement Update: Importantly, the previous BUS rule requiring the EPC to have no outstanding recommendations for loft or cavity wall insulation was removed in May 2024.4 This change simplifies access to the grant, potentially aiming to increase uptake which had been slower than initially targeted.29 However, while no longer a formal requirement for the grant, installing adequate insulation remains strongly recommended to ensure the heat pump operates efficiently and delivers the expected comfort and running cost benefits.4 Without sufficient insulation, homeowners might experience higher running costs or find their homes less comfortable, potentially undermining long-term satisfaction with the system, even though the grant was easier to obtain.

• Application Process: The application process is managed by the MCS-certified installer, not the homeowner.7 The homeowner selects an installer, agrees on a quote, and the installer applies for the grant voucher via the scheme administrator, Ofgem. The grant value (£7,500 for ASHPs) is deducted directly from the homeowner's invoice. Ofgem will contact the homeowner via email to confirm their consent for the installer to act on their behalf.7

• Scheme Duration: The Boiler Upgrade Scheme is currently scheduled to run until 31 December 2027.7

• Other Relevant Schemes (Brief Overview): While BUS is the main grant for ASHPs, other schemes may help with associated costs like insulation:

• Energy Company Obligation (ECO4): This scheme requires large energy suppliers to fund energy efficiency improvements in low-income and vulnerable households living in properties with poor energy efficiency (EPC band D-G).17 ECO4 focuses on a 'whole house' approach, potentially including insulation, heating upgrades (ASHPs can be funded as part of a package 17), and solar PV.17 Eligibility is often linked to receipt of specific means-tested benefits.32 The scheme runs until March 2026.17 Local authorities can use 'Flexible Eligibility' (LA Flex) criteria to widen access for households not on standard qualifying benefits but still considered fuel poor or vulnerable.36 Applications are typically made via energy suppliers or their approved installers.41

• Great British Insulation Scheme (GBIS): Running alongside ECO4 until March 2026, GBIS primarily funds single insulation measures (like loft or cavity wall insulation).37 It targets a broader group than ECO4, including households in Council Tax bands A-D (in England) with an EPC of D-G, as well as low-income households.33 While unlikely to fund an ASHP directly, it can help cover necessary insulation upgrades.43 Applications are generally made via energy suppliers.41

• Warm Homes: Local Grant (England): This scheme, delivered by local authorities, provides funding for energy efficiency upgrades (insulation, solar PV) and low-carbon heating (including ASHPs) to low-income households (gross income <£36k, or receiving benefits, or in deprived areas) in privately owned homes (owner-occupied or rented) with an EPC of D-G.31 Funding runs until March 2028.31 Homeowners can check eligibility and apply via a GOV.UK tool or by contacting their local authority.49

• Combining Grants: A frequently asked question is whether funding from different schemes can be combined. The BUS grant cannot be combined with other public funds specifically for the purchase or installation of the heat pump itself.7 However, it can generally be used alongside separate funding obtained for different energy efficiency measures, such as insulation funded through ECO4, GBIS, or the Warm Homes: Local Grant, provided the eligibility criteria for each scheme are met independently.7 Navigating multiple schemes can be complex due to differing eligibility rules, application routes (installer-led, supplier-led, LA-led), and timelines.54 This fragmented landscape underscores the need for homeowners to seek reliable, independent advice from organisations like the Energy Saving Trust or local support services (e.g., East Sussex's Warm Home Check service 56) to understand their options fully.Table 2: Overview of Key UK Home Energy Grants (England & Wales Focus)

Scheme Name

Primary Focus

Key Eligibility Summary

Funding Available (Examples)

How to Apply

Current End Date

Scheme Name

Primary Focus

Key Eligibility Summary

Funding Available (Examples)

How to Apply

Current End Date

Snippet IDs

Snippet IDs

Boiler Upgrade Scheme (BUS)

Low-carbon heating (Heat Pumps, Biomass Boilers)

Property owner (Eng/Wales), replacing fossil/electric heat, valid EPC, not new build/social housing. No mandatory insulation requirement.

£7,500 grant for ASHP/GSHP

Via MCS Certified Installer

Dec 31, 2027

Boiler Upgrade Scheme (BUS)

Low-carbon heating (Heat Pumps, Biomass Boilers)

Property owner (Eng/Wales), replacing fossil/electric heat, valid EPC, not new build/social housing. No mandatory insulation requirement.

£7,500 grant for ASHP/GSHP

Via MCS Certified Installer

Dec 31, 2027

7

7

Energy Company Obligation (ECO4)

Whole-house retrofit for low-income/vulnerable

Low income (benefits), EPC D-G, private tenure (owner/tenant) or social housing. LA Flex widens criteria.

Multiple measures (insulation, heating including ASHP, solar PV) - often fully funded.

Via Energy Supplier or approved installer

Mar 31, 2026

Energy Company Obligation (ECO4)

Whole-house retrofit for low-income/vulnerable

Low income (benefits), EPC D-G, private tenure (owner/tenant) or social housing. LA Flex widens criteria.

Multiple measures (insulation, heating including ASHP, solar PV) - often fully funded.

Via Energy Supplier or approved installer

Mar 31, 2026

17

17

Great British Insulation Scheme (GBIS)

Single insulation measures (mainly)

Low income (benefits) OR Council Tax Band A-D (Eng) / A-E (Sco/Wal) + EPC D-G. Private tenure (owner/tenant) or social housing.

Free or subsidised insulation (e.g., cavity, loft).

Via Energy Supplier or GOV.UK eligibility checker

Mar 31, 2026

Great British Insulation Scheme (GBIS)

Single insulation measures (mainly)

Low income (benefits) OR Council Tax Band A-D (Eng) / A-E (Sco/Wal) + EPC D-G. Private tenure (owner/tenant) or social housing.

Free or subsidised insulation (e.g., cavity, loft).

Via Energy Supplier or GOV.UK eligibility checker

Mar 31, 2026

33

33

Warm Homes: Local Grant (England)

Energy efficiency & low-carbon heat for low income

Low income (<£36k), or benefits, or deprived area. EPC D-G. Private tenure (owner/tenant).

Up to £15k (efficiency) + £15k (low carbon heat). Landlords may need to contribute for multiple properties.

Via GOV.UK tool or Local Authority

Mar 31, 2028

Warm Homes: Local Grant (England)

Energy efficiency & low-carbon heat for low income

Low income (<£36k), or benefits, or deprived area. EPC D-G. Private tenure (owner/tenant).

Up to £15k (efficiency) + £15k (low carbon heat). Landlords may need to contribute for multiple properties.

Via GOV.UK tool or Local Authority

Mar 31, 2028

31

31

Finding and Choosing an Installer

Selecting a competent and trustworthy installer is critical for a successful ASHP installation and for accessing available grants.

• The Importance of MCS Certification: For homeowners wishing to claim the £7,500 Boiler Upgrade Scheme (BUS) grant, using an installer certified under the Microgeneration Certification Scheme (MCS) is mandatory.7 MCS certification provides assurance that the installer is technically competent, uses MCS-approved products that meet quality and performance standards, and adheres to a consumer code offering protection.18 An MCS certificate for the installation is required for the grant process and is usually provided to the homeowner upon completion.18

• Using TrustMark: It is also highly recommended to choose an installer who is registered with TrustMark, the UK Government Endorsed Quality Scheme for work done in and around the home.17 TrustMark registration signifies that the business has been thoroughly vetted and operates to required technical standards, such as PAS 2030/2035 for energy efficiency retrofit work.37 This provides an additional layer of consumer protection and quality assurance. While recent quality issues identified with solid wall insulation under the ECO4 and GBIS schemes highlight that accreditation systems are not infallible 65, using installers accredited by both MCS and TrustMark offers the strongest available assurance of competence and recourse if problems arise.

• Finding Installers: Homeowners can search for MCS certified installers using the official MCS 'Find an Installer' tool available on their website.7 Local recommendations or directories listing installers operating in specific areas, such as Sussex, can also be useful resources.71 Examples of MCS certified companies operating in the South East include DH Solar Engineering, South East Solar and Storage, Option Energy Solutions Ltd, and Holland & Johnston Ltd, among others.1

• Getting Quotes: It is advisable to obtain detailed quotes from at least three different MCS certified installers.61 When comparing quotes, homeowners should look beyond the bottom-line price and consider the specifics of the proposed system design (including heat loss calculations and recommended emitter sizes), the warranties offered on equipment and workmanship, the installer's experience and track record, and independent customer reviews or references.73

• What to Expect: The process typically involves an initial consultation and a detailed survey of the property, including a heat loss assessment.21 Based on this, the installer will propose a suitable system design and provide a comprehensive quote. If accepted, the installer will manage the BUS grant application and schedule the installation work.7 The installer's role is crucial not only for the physical fitting but also for ensuring the system is correctly sized and designed for the specific property, which directly impacts its efficiency and the homeowner's ability to access funding.7 Therefore, selecting an installer based on demonstrated competence in both technical design and administrative processes is paramount.

Conclusion – Is an ASHP the Right Choice for Your Home?

Air Source Heat Pumps represent a highly efficient, low-carbon heating solution that aligns with the UK's environmental goals and offers the potential for long-term savings on energy bills. Key advantages include their superior energy efficiency compared to boilers, significant carbon footprint reduction, eligibility for a substantial £7,500 government grant (BUS), and typically longer lifespan with low maintenance needs.

However, homeowners must carefully weigh these benefits against important considerations. The upfront cost, even after the grant, remains a significant investment, potentially increased by necessary upgrades to home insulation or radiators. Ensuring the property is suitable – particularly regarding insulation levels and the heat distribution system (radiators/underfloor heating) – is crucial for the ASHP to operate efficiently and provide adequate comfort, especially during colder periods. Noise from the outdoor unit is a common concern, although modern units are quiet and subject to regulation.

Ultimately, the decision involves assessing individual circumstances. Key factors include the current heating system (savings are typically greater when replacing older, less efficient oil, LPG, or electric systems), the property's existing insulation levels, the available budget for the installation and any necessary upgrades, and the homeowner's priorities (balancing cost savings with environmental benefits). Installing an ASHP is more than just a like-for-like replacement; it's an investment in a different way of heating that aligns the home with the UK's long-term decarbonisation strategy.1 This "future-proofing" aspect may offer benefits beyond immediate running costs, potentially increasing property value 75 and ensuring compliance with future heating regulations.

For homeowners considering an ASHP, the recommended next steps are:

1. Assess Home Suitability: Evaluate your home's insulation levels (consider getting an Energy Performance Certificate (EPC) if you don't have a recent one 31). Understand that good insulation is key to ASHP performance.4

2. Initial Research: Use online resources and calculators (e.g., from the Energy Saving Trust 76) to get a preliminary idea of potential system size, costs, and savings.

3. Contact Installers: Find and contact several MCS certified installers.7 Request detailed surveys, heat loss calculations, system proposals, and quotes.73

4. Discuss Grants: Confirm your eligibility for the £7,500 Boiler Upgrade Scheme grant with the installers.7

5. Explore Additional Support: Investigate if you might be eligible for insulation grants or other support through schemes like ECO4, GBIS, or the Warm Homes: Local Grant, potentially via your energy supplier or local authority.34

Given the technical considerations and the complexities of navigating grants, homeowners should engage proactively in the process. Asking detailed questions, comparing quotes thoroughly, and understanding the proposed system design are essential for ensuring a successful installation that delivers warmth, efficiency, and value for years to come.

Works cited

1. Heat and buildings strategy - GOV.UK, accessed on May 7, 2025, https://www.gov.uk/government/publications/heat-and-buildings-strategy

2. The Seventh Carbon Budget - Climate Change Committee, accessed on May 7, 2025, https://www.theccc.org.uk/publication/the-seventh-carbon-budget/

3. Delegated Decision report - North East Combined Authority, accessed on May 7, 2025, https://www.northeast-ca.gov.uk/downloads/3493/250305-delegated-decision-report-retrofit-advice-programme-short-term-contract-extension.pdf

4. Should I insulate my house before getting a heat pump? - Cinergi, accessed on May 8, 2025, https://cinergi.co.uk/should-i-insulate-my-house-before-getting-a-heat-pump/

5. Heat-Pump - Energy Efficient Home, accessed on May 8, 2025, https://energy-efficient-home.campaign.gov.uk/heat-pump/

6. Air source heat pumps: costs, savings and benefits - Energy Saving ..., accessed on May 8, 2025, https://energysavingtrust.org.uk/advice/air-source-heat-pumps/

7. Boiler Upgrade Scheme - GOV-UK Find a grant, accessed on May 8, 2025, https://www.find-government-grants.service.gov.uk/grants/boiler-upgrade-scheme-1

8. A Guide To Air Source Heat Pumps And Radiators, accessed on May 8, 2025, https://www.radiatorsdirect.co.uk/post/a-guide-to-air-source-heat-pumps-and-radiators

9. energysavingtrust.org.uk, accessed on May 8, 2025, https://energysavingtrust.org.uk/advice/air-source-heat-pumps/#:~:text=An%20air%20source%20heat%20pump,taps%2C%20showers%2C%20and%20baths.

10. Do Heat Pumps Work in Winter and Cold Weather? | Ideal Heating, accessed on May 8, 2025, https://idealheating.com/tips-and-advice/heat-pumps-cold-weather

11. COP - Heat Pump Efficiency - Residential Energy Library, accessed on May 8, 2025, https://c03.apogee.net/mvc/home/hes/land/el?utilityname=ashley-chicot&spc=hel&id=15720

12. Heat Pump COP and SCOP: What They Mean & Why They Matter, accessed on May 8, 2025, https://www.h2xengineering.com/blogs/heat-pump-cop-and-scop-what-they-mean-and-why-they-matter/

13. Advantages & Disadvantages of Heat Pumps | FAQs – Grant UK, accessed on May 8, 2025, https://www.grantuk.com/knowledge-hub/faqs/what-are-the-advantages-and-disadvantages-of-heat-pumps/

14. Is A Heat Pump Cheaper Than A Boiler? Cost Comparison Guide ..., accessed on May 8, 2025, https://iheat.co.uk/boiler-help/is-a-heat-pump-cheaper-than-a-boiler

15. Smart heating choices: Are heat pumps worth it? - Eon Next, accessed on May 8, 2025, https://www.eonnext.com/blog/smart-heating-choices-are-heat-pumps-worth-it

16. Do Heat Pumps Work In Cold Weather in the UK? - GreenMatch, accessed on May 8, 2025, https://www.greenmatch.co.uk/heat-pumps/cold-weather

17. Energy Company Obligation - Wikipedia, accessed on May 7, 2025, https://en.wikipedia.org/wiki/Energy_Company_Obligation

18. Apply for the Boiler Upgrade Scheme: Overview - GOV.UK, accessed on May 8, 2025, https://www.gov.uk/apply-boiler-upgrade-scheme

19. Everything you need to know about the Boiler Upgrade Scheme - The Eco Experts, accessed on May 7, 2025, https://www.theecoexperts.co.uk/news/boiler-upgrade-scheme

20. What Impact Does Insulation Have on Air Source Heat Pump ..., accessed on May 8, 2025, https://yourenergyuk.co.uk/what-impact-does-insulation-have-on-air-source-heat-pump-efficiency/

21. What Size Air Source Heat Pump Do I Need For My Home?, accessed on May 8, 2025, https://heat-pumps.org.uk/what-size-air-source-heat-pump-do-i-need-for-my-home/

22. Are heat pumps noisy and is there regulation on noise? | Nesta, accessed on May 8, 2025, https://www.nesta.org.uk/report/what-homeowners-want-to-know-about-heat-pumps-data-driven-faqs/are-heat-pumps-noisy-and-is-there-regulation-on-noise/

23. Air Source Heat Pump Noise: How Noisy Are They? - GreenMatch, accessed on May 8, 2025, https://www.greenmatch.co.uk/heat-pumps/noise

24. The Quiet Mark® Certified Guide to the Quietest Heat Pumps ..., accessed on May 8, 2025, https://architecturemagazine.co.uk/2025/03/31/the-quiet-mark-certified-guide-to-the-quietest-heat-pumps/

25. Grant Aerona³ R32 Air Source Heat Pump 13kW - Quiet Mark, accessed on May 8, 2025, https://www.quietmark.com/products/grant-aerona3-r32-air-source-heat-pump

26. Boiler Upgrade Scheme: Guidance for Property Owners | Ofgem, accessed on May 8, 2025, https://www.ofgem.gov.uk/publications/boiler-upgrade-scheme-guidance-property-owners

27. How Hot Do Radiators Get With an Air Source Heat Pump? | Greentech Renewables Ltd, accessed on May 8, 2025, https://www.greentechrenewables.co.uk/ashp/how-hot-do-radiators-get-with-an-air-source-heat-pump/

28. The Boiler Upgrade Scheme Explained - Wealden Renewables, accessed on May 7, 2025, https://wealdenrenewables.co.uk/the-boiler-upgrade-scheme-explained/

29. Understanding public perceptions of the Boiler Upgrade Scheme - Nesta, accessed on May 7, 2025, https://www.nesta.org.uk/project-updates/understanding-public-perceptions-of-the-boiler-upgrade-scheme/

30. Why has the government's Boiler Upgrade Scheme been so heavily criticised?, accessed on May 7, 2025, https://www.pbctoday.co.uk/news/energy-news/why-has-the-governments-boiler-upgrade-scheme-been-heavily-criticised/124856/

31. UK government grants for home improvements [2025 guide], accessed on May 7, 2025, https://www.calderwindows.co.uk/uk-government-grants-for-home-improvements-2025-guide

32. Energy Company Obligation (ECO) | Ofgem, accessed on May 7, 2025, https://www.ofgem.gov.uk/environmental-and-social-schemes/energy-company-obligation-eco

33. Energy Grants In 2025 And How To Get Them - HomeOwners Alliance, accessed on May 7, 2025, https://hoa.org.uk/advice/guides-for-homeowners/for-owners/energy-grants/

34. Find energy grants for your home (Help to Heat) - GOV.UK, accessed on May 7, 2025, https://www.gov.uk/government/collections/find-energy-grants-for-you-home-help-to-heat

35. ECO4 scheme - Stockton-on-Tees Borough Council, accessed on May 7, 2025, https://www.stockton.gov.uk/article/12060/ECO4-scheme

36. The ECO4 solar panel scheme: do you qualify? [UK, 2025] - Sunsave, accessed on May 7, 2025, https://www.sunsave.energy/solar-panels-advice/costs/eco4-scheme

37. Energy Company Obligation 4 and the Great British Insulation Scheme: mid-scheme changes - consultation - GOV.UK, accessed on May 7, 2025, https://www.gov.uk/government/consultations/energy-company-obligation-4-and-the-great-british-insulation-scheme-mid-scheme-changes/energy-company-obligation-4-and-the-great-british-insulation-scheme-mid-scheme-changes-consultation

38. Statement of Intent for ECO4 - Eastbourne Borough Council, accessed on May 7, 2025, https://www.lewes-eastbourne.gov.uk/media/3565/East-Sussex-ECO4-Flex-Statement-of-Intent-October-2023/pdf/East_Sussex_ECO4_Flex_Statement_of_Intent_-_October_2023.pdf?m=1696583991177

39. East Sussex ECO4 Flexible Eligibility Statement of Intent - Hastings Borough Council, accessed on May 7, 2025, https://www.hastings.gov.uk/content/energy_efficiency/East_Sussex_ECO4_Flexible_Eligibility_Statement_of_Intent_V1_(17.10.22).pdf

40. www.hastings.gov.uk, accessed on May 7, 2025, https://www.hastings.gov.uk/content/energy_efficiency/SOI_07-08-24.pdf

41. Applying for home energy efficiency grants: step-by-step guide - Snugg, accessed on May 7, 2025, https://www.snugg.com/blog/applying-for-home-energy-efficiency-grants-a-step-by-step-guide

42. UK green energy grants: Find support for home improvements - Saga, accessed on May 7, 2025, https://www.saga.co.uk/saga-money-news/uk-green-energy-grants

43. Summary of the Great British Insulation Scheme: February 2025 ..., accessed on May 7, 2025, https://www.gov.uk/government/statistics/great-british-insulation-scheme-release-february-2025/summary-of-the-great-british-insulation-scheme-february-2025

44. Summary of the Great British Insulation Scheme: March 2025 - GOV.UK, accessed on May 7, 2025, https://www.gov.uk/government/statistics/great-british-insulation-scheme-release-march-2025/summary-of-the-great-british-insulation-scheme-march-2025

45. Great British Insulation Scheme | Ofgem, accessed on May 7, 2025, https://www.ofgem.gov.uk/environmental-and-social-schemes/great-british-insulation-scheme

46. Great British Insulation Scheme (GBIS) - TrustMark, accessed on May 7, 2025, https://www.trustmark.org.uk/homeowner/funding/great-british-insulation-scheme/

47. Apply for support from the Great British Insulation Scheme - GOV.UK, accessed on May 7, 2025, https://www.gov.uk/apply-great-british-insulation-scheme

48. MD3366 Warm Homes Local Grant 2025-2028 - Greater London Authority, accessed on May 7, 2025, https://www.london.gov.uk/md3366-warm-homes-local-grant-2025-2028

49. Warm Homes: Local Grant — a guide for local authorities - Energy Saving Trust, accessed on May 7, 2025, https://energysavingtrust.org.uk/warm-homes-local-grant-a-guide-for-local-authorities/

50. REQUEST FOR MAYORAL DECISION MD3366 - Title: Warm Homes Local Grant 2025-2028 - Greater London Authority, accessed on May 7, 2025, https://www.london.gov.uk/media/108442/download

51. Energy efficiency: Landlord funding pot now live - NRLA, accessed on May 7, 2025, https://www.nrla.org.uk/news/energy-efficiency-landlord-funding-pot-now-live

52. Apply for the Warm Homes: Local Grant to improve a home - GOV.UK, accessed on May 7, 2025, https://www.gov.uk/apply-warm-homes-local-grant

53. Funding and grants - Warm East Sussex, accessed on May 7, 2025, https://www.warmeastsussex.org.uk/funding

54. Difficulties in Accessing ECO4 Grants | Consumer Rights, accessed on May 7, 2025, https://www.consumer-rights.org/eco/the-difficulties-in-accessing-eco4-grants/

55. The Challenges of Accessing Energy Funding - Consumer Rights, accessed on May 7, 2025, https://www.consumer-rights.org/grants/the-challenges-of-accessing-energy-funding/

56. East Sussex Warm Home Check service - Retrofitworks, accessed on May 7, 2025, https://retrofitworks.co.uk/east-sussex/

57. Warm East Sussex, accessed on May 7, 2025, https://www.warmeastsussex.org.uk/

58. Warm Home Check service - Warm East Sussex, accessed on May 7, 2025, https://www.warmeastsussex.org.uk/warm-home-check

59. Solar Panels - Energy Efficient Home, accessed on May 7, 2025, https://energy-efficient-home.campaign.gov.uk/solar/

60. The Importance of Being a MCS Certified Installer | Grant UK, accessed on May 8, 2025, https://www.grantuk.com/about/blog/the-importance-of-being-a-mcs-certified-installer/

61. MCS Certified | Giving you confidence in home-grown energy, accessed on May 8, 2025, https://mcscertified.com/

62. Energy Company Obligation 4 and the Great British Insulation Scheme: mid-scheme changes - final stage impact assessment - GOV.UK, accessed on May 7, 2025, https://www.gov.uk/government/consultations/energy-company-obligation-4-and-the-great-british-insulation-scheme-mid-scheme-changes/outcome/energy-company-obligation-4-and-the-great-british-insulation-scheme-mid-scheme-changes-final-stage-impact-assessment

63. Warm Home: Local Grant, Eligible Measures and Quality Standards, accessed on May 7, 2025, https://cms.wiltshire.gov.uk/documents/s234888/Cabinet_Report_Eligible_Measures__%20Qulaity_Standards_Appendix_1.pdf

64. Home energy – Herefordshire Council, accessed on May 7, 2025, https://www.herefordshire.gov.uk/housing-3/home-energy/5

65. Grants and loans - Local Authority Flexible Eligibility Statement of Intent - East Devon, accessed on May 7, 2025, https://eastdevon.gov.uk/housing-and-homelessness/private-sector-housing/private-sector-housing/grants-and-loans/local-authority-flexible-eligibility-statement-of-intent/

66. ECO4 and Insulation Schemes - Hansard - UK Parliament, accessed on May 7, 2025, https://hansard.parliament.uk/commons/2025-01-23/debates/681FE84D-E6D8-46AA-8754-AF391F4E3500/ECO4AndInsulationSchemes

67. Action taken to protect households with poor-quality insulation - GOV.UK, accessed on May 7, 2025, https://www.gov.uk/government/news/action-taken-to-protect-households-with-poor-quality-insulation

68. ECO4 and Insulation Schemes - Hansard - UK Parliament, accessed on May 7, 2025, https://hansard.parliament.uk/Lords/2025-01-29/debates/9535EF32-DFD3-4810-8690-5A34516F1FBE/ECO4AndInsulationSchemes

69. Problem with building work, decorating or home improvements - Citizens Advice, accessed on May 7, 2025, https://www.citizensadvice.org.uk/consumer/getting-home-improvements-done/problem-with-home-improvements/

70. What to do if you have poor quality wall insulation - GOV.UK, accessed on May 7, 2025, https://www.gov.uk/guidance/what-to-do-if-you-have-poor-quality-wall-insulation

71. Solar Panels & Solar PV Installers in East Sussex - The Renewable Energy Hub, accessed on May 8, 2025, https://www.renewableenergyhub.co.uk/solar-panel-solar-pv-installers-in-east-sussex

72. Solar Panel Systems in Sussex - PDP Services, accessed on May 8, 2025, https://pdp.services/solar-panels/solar-panel-systems-in-sussex/

73. How to Choose a Solar Panel Installer in 2025 | 9 Top Tips - The Eco Experts, accessed on May 8, 2025, https://www.theecoexperts.co.uk/solar-panels/how-to-choose-a-solar-installer

74. 15 Best Solar Panel Installers/Companies UK (2025) | Glow Green, accessed on May 8, 2025, https://www.glowgreenltd.com/solar-advice/best-solar-panel-installers

75. The Long-Term Benefits of Solar Panels - Save Energy UK, accessed on May 8, 2025, https://saveenergyuk.co.uk/the-long-term-benefits-of-solar-panels-for-uk-residential-properties/

76. Solar panels: costs, savings and benefits explained - Energy Saving ..., accessed on May 8, 2025, https://www.energysavingtrust.org.uk/advice/solar-panels/