If you have arrived here because of the £7,500, this page may not tell you what you were hoping to read. That is deliberate.
Eco Connect Services is an independent advisory business. We do not install heat pumps and we cannot apply for the grant for you. What we can do is set out honestly what decides whether a heat pump works well in a particular building, because the grant does not ask that question and the person quoting you has an interest in the answer.
A heat pump in the right property is an excellent piece of equipment. A heat pump in a property that is not ready for one produces disappointing warmth, high running costs and a homeowner who tells everyone that heat pumps do not work. The difference between those two outcomes is almost entirely the building, not the machine.
The one thing that decides most of it
A gas or oil boiler makes water very hot and pushes it round small radiators. A heat pump makes water moderately warm and needs to push it round for longer, through larger surfaces. It is the same amount of heat delivered a gentler way.
That single difference is why the building matters so much more than it did with a boiler. If a property loses heat quickly, a boiler compensates by running hotter. A heat pump has much less room to do that, and the cost of trying shows up on your electricity bill every day for the next fifteen years.
Ofgem, which administers the government’s heat pump grant, puts it in one sentence in its guidance to property owners: heat pumps perform best in a well-insulated home. It goes on to say that insulation measures such as cavity wall or loft insulation can significantly reduce heat loss and may help improve the performance of a low carbon heating system, and that the government recommends you consider energy efficiency upgrades where practical and affordable to do so.
Note the register of that language. It is a recommendation, not a requirement. We will come back to why that matters.
Source: Ofgem, “Boiler Upgrade Scheme guidance for property owners”, version 5.1, published 2 July 2026, paragraphs 4.08 to 4.12. Checked 17 August 2026. https://www.ofgem.gov.uk/guidance/boiler-upgrade-scheme-guidance-property-owners
Fabric first: what that actually means
“Fabric first” is a phrase that gets used loosely. In practice it means working through the building before the plant, roughly in this order:
- Loft insulation. Usually the cheapest heat you will ever save, and the easiest to check yourself with a tape measure and a torch.
- Cavity walls, where you have them and they are suitable. Not every wall is a cavity, and not every cavity should be filled. This one needs looking at rather than assuming.
- Draughts and air tightness. Unglamorous, cheap, and frequently the difference between a room that feels warm at 20 degrees and one that does not.
- Glazing and doors. Usually further down the list on cost per unit of heat saved, but relevant where it is bad.
- Ventilation. This one runs the other way. As you tighten a building you have to think about moisture and air quality, not just heat. Sealing a property without thinking about ventilation trades a heating problem for a damp problem.
You do not have to do all of it, and there is a real point at which further work stops paying. But the order matters, because every one of these changes the size of heat pump you need. Doing them afterwards means you have already bought and paid for a larger machine than the finished building requires.
GOV.UK’s own list of questions to put to an installer includes exactly this one: are there any changes I can make to my property to reduce my bills, or allow me to get a smaller heat pump. Its examples include new radiators and a new hot water tank.
Source: GOV.UK, “Find a heat pump installer”, published 5 July 2022, “What to ask your installer”. Checked 17 August 2026. https://www.gov.uk/guidance/find-a-heat-pump-installer
Radiators, pipework and the hot water cylinder
Lower flow temperature means each radiator gives out less heat than it did on a boiler. To deliver the same warmth, the surface has to be larger: a bigger radiator, a deeper one, or in some rooms a different type of emitter altogether. Sometimes the existing pipework is too narrow to carry the flow rate the system needs, and that is a floor-up job rather than a swap.
Underfloor heating suits a heat pump particularly well, because it is a very large, very low temperature emitter by design. That is a reason it comes up so often in heat pump conversations, not a requirement.
Then there is hot water. A combi boiler makes hot water on demand and takes up no more space than the boiler. Most heat pump systems need a hot water cylinder, and the cylinder needs somewhere to live. In a house that lost its airing cupboard to a combi swap fifteen years ago, that is a genuine planning problem and it is better discovered now than on installation day.
This is why a proper assessment is a survey and not a phone call. Ofgem’s guidance says your installer should come to your property to undertake a heat loss assessment and provide a quote and a bill impact assessment. Total building heat loss calculations are among the documents Ofgem may ask to see when it audits an installation. Ofgem also says your installer should be willing to explain which technologies could work in your property, how installation would affect your home, including heat emitters and space requirements, and whether any upgrades such as radiators may be needed.
If nobody has visited and nobody has produced a heat loss calculation, you do not yet have a proposal. You have a price.
Source: Ofgem, “Boiler Upgrade Scheme guidance for property owners”, version 5.1, published 2 July 2026, paragraphs 4.13, 4.16 and 5.08. Checked 17 August 2026.
The electrical side, which is where we are actually useful
A heat pump is an electrical load, and it is a load that runs for hours rather than minutes. It sits alongside whatever else you have already added, such as an EV charger, an induction hob or a shower, on an incoming supply that was sized for a house that had none of them.
GOV.UK’s guidance is that most heat pumps can be installed without having to make changes to your electricity supply, and it lists “do I need to upgrade my electricity supply, and if so how much will this cost” as one of the questions to ask before you commit. Both halves of that are worth holding on to. It is usually fine. It is not automatically fine, and finding out late is expensive.
The things worth establishing before anyone quotes:
- the capacity of your incoming supply, and whether it is single or three phase;
- the condition and spare capacity of your consumer unit;
- what else you have already added, or intend to add, on the same supply;
- whether solar or battery storage is part of your plan, because that changes the electrical design and it is cheaper to design once than twice;
- who is notifying your distribution network operator, and of what.
This is the part of the picture Eco Connect can genuinely help with, and it is the reason we publish this page at all. It is also where a heat pump conversation and a solar conversation turn out to be the same conversation, held by the same household, about the same building.
Source: GOV.UK, “Find a heat pump installer”, published 5 July 2022, “What to ask your installer”. Checked 17 August 2026.
What the grant requires, and what it does not
The Boiler Upgrade Scheme is a government grant administered by Ofgem, open in England and Wales. As at 17 August 2026, the published grant values are:
- £7,500 towards an air-to-water heat pump, a ground source heat pump or a water source heat pump;
- £2,500 towards an air-to-air heat pump, in residential properties only;
- £5,000 towards a biomass boiler;
- £9,000 towards an air-to-water or ground source heat pump in an off-gas-grid property replacing oil or LPG heating. This uplifted value is available for applications properly made between 21 July 2026 and 31 March 2027.
You can get one grant per property. You cannot get a grant for a hybrid system, such as a gas boiler combined with an air source heat pump, and you cannot get one to replace a heating system that is already low carbon.
Who is eligible. You must own the property, including where it is a business, a second home or a property you let, and you must be replacing a fossil fuel heating system such as oil, gas, electric or LPG. Ofgem’s guidance frames the same test as replacing a fossil fuel or an electric heating system, excluding existing heat pumps. You are still eligible if you have already had funding to make the property more energy efficient, for example by insulating it.
What is excluded. Most new build properties, social housing, and any property that has already had government funding or support for a heat pump or biomass boiler. Certain self-build properties are an exception to the new build rule and can qualify, though not for the uplifted value.
Who applies. Not you. The scheme is installer-led and Ofgem states that you cannot apply yourself. You choose an MCS certified installer, agree a quotation, and the installer applies on your behalf and redeems the grant after installation. The grant is applied upfront as a discount and appears on your quotation and invoice. Ofgem will then contact you directly to confirm your consent and verify your identity, and you have 14 days to respond or the application may be rejected.
Now the part that matters for this page. There is no insulation condition and no EPC condition. Ofgem’s current property owner guidance treats energy efficiency as advice: it recommends you consider upgrades where practical and affordable, and recommends you discuss them with your installer as part of the design process. It does not require them. An EPC appears in the process only as one way of evidencing eligibility, and Ofgem’s guidance explicitly sets out what to do if your property does not have a valid one.
So the scheme will not stop you. It will not check that your loft is insulated, it will not require you to act on an EPC recommendation, and it will not tell you that your radiators are too small. The grant answers the question “may this property have a subsidised heat pump”. It does not answer the question “should this property have one yet”. That second question is the one worth paying attention to, and nobody is obliged to ask it on your behalf.
Sources: GOV.UK, “Apply for the Boiler Upgrade Scheme”, overview, what you can get, check if you’re eligible, and how to apply, page last updated 6 August 2026; Ofgem, “Boiler Upgrade Scheme (BUS)” scheme page; Ofgem, “Boiler Upgrade Scheme guidance for property owners”, version 5.1, published 2 July 2026, paragraphs 1.02, 1.05, 3.05, 3.07, 3.11–3.14, 4.02, 4.08–4.12, 4.21–4.24 and 4.33–4.34. All checked 17 August 2026. https://www.gov.uk/apply-boiler-upgrade-scheme https://www.ofgem.gov.uk/environmental-and-social-schemes/boiler-upgrade-scheme-bus https://www.ofgem.gov.uk/guidance/boiler-upgrade-scheme-guidance-property-owners
How long you have, once you start
There are deadlines in the process and they are not all described the same way in every place, so it is worth going to the administrator’s own guidance.
Ofgem’s version 5.1 guidance says a voucher must be redeemed within a set validity period: the installer must complete the work, commission the system and redeem the voucher within three months for an air-to-water heat pump, an air-to-air heat pump or a biomass boiler, and within six months for a ground source heat pump. Separately, where an installation has already been commissioned, an installer may apply retrospectively provided the application is properly made within 120 days of commissioning. Ofgem warns that retrospective applications carry additional risk.
GOV.UK’s summary page words the timing differently, saying your installer must commission and install the heat pump within 120 days of applying for the grant or it will not be eligible.
We are pointing out the difference rather than resolving it. Where a summary page and the scheme administrator’s own guidance describe a deadline differently, follow the administrator’s guidance and ask your installer to confirm which period applies to your application.
Sources: Ofgem, “Boiler Upgrade Scheme guidance for property owners”, version 5.1, paragraphs 4.30, 4.31 and 4.54; GOV.UK, “Apply for the Boiler Upgrade Scheme”, check if you’re eligible. Both checked 17 August 2026.
Who is allowed to install one
For a grant-funded installation, the installer must be certified under the Microgeneration Certification Scheme, usually written MCS. Ofgem’s guidance states that all Boiler Upgrade Scheme installations must be carried out by MCS certified installers, and that installers working with consumers must also be members of a consumer code approved by the Secretary of State.
GOV.UK explains what MCS certification means in practice: that the installer is technically competent and that the products they use meet the correct standards. MCS certified installers must also be registered with a consumer protection scheme such as RECC or HIES, so you have somewhere to go if something goes wrong. GOV.UK also recommends getting quotes from more than one installer, and says that if you used an MCS certified installer you should receive an MCS commissioning certificate within 10 days of completion. Keep it.
One more question worth asking, from GOV.UK’s own list: can you self-certify that the work complies with building regulations. An installer who is a member of a Competent Person Scheme can, which means you do not need a separate building regulations approval for the work.
To be explicit about our own position: Eco Connect is not MCS certified, does not hold any installation accreditation, and does not carry out this work. Certification belongs to installers. If anyone tells you otherwise about us, they are wrong.
Sources: Ofgem, “Boiler Upgrade Scheme guidance for property owners”, version 5.1, paragraphs 2.06, 2.08, 2.10, 2.11, 4.02 and 4.56; GOV.UK, “Find a heat pump installer”. Both checked 17 August 2026. https://www.gov.uk/guidance/find-a-heat-pump-installer https://mcscertified.com/find-an-installer/
Planning permission for an air source heat pump
An air source heat pump on a house or a block of flats in England is usually permitted development, which means planning permission is granted nationally rather than applied for from your council. It is not a blanket permission and the limits are specific.
The permitted development right applies to a microgeneration air source heat pump on, or within the curtilage of, a house or a block of flats. It does not apply unless the heat pump complies with the MCS Planning Standards.
Beyond that, the right does not apply if:
- there would be more than one air source heat pump on or within the curtilage of a house that is not detached, or of a block of flats, or more than two on or within the curtilage of a detached house;
- a wind turbine, or a stand-alone wind turbine, is already installed on the same building or within the curtilage;
- the volume of the outdoor compressor unit, including any housing, would exceed 1.5 cubic metres at a house, or 0.6 cubic metres at a block of flats;
- it would be installed on a pitched roof, or on a flat roof within 1 metre of the external edge of that roof;
- it would be installed on a site designated as a scheduled monument;
- it would be installed on, or on land within the curtilage of, a listed building;
- in a conservation area or a World Heritage Site, it would go on a wall or roof fronting a highway, or nearer to the highway than the nearest part of the building;
- elsewhere, it would go on a wall fronting a highway above the level of the ground floor storey.
Three conditions also apply: the heat pump must not be used solely for cooling; it must be sited, so far as practicable, to minimise its effect on the external appearance of the building and on the amenity of the area; and it must be removed as soon as reasonably practicable when no longer needed.
The rules for ground and water source systems are different again and can involve environmental permits or exemptions rather than planning permission. GOV.UK publishes separate guidance on open loop and closed loop systems, linked from its heat pump installer page.
Source: The Town and Country Planning (General Permitted Development) (England) Order 2015, Schedule 2, Part 14, Class G, as amended. The published text is stated to be valid as at 9 April 2026 and last modified 22 July 2026. Class G was last amended by S.I. 2025/560, in force 29 May 2025. Checked 17 August 2026. https://www.legislation.gov.uk/uksi/2015/596/schedule/2/part/14
One thing that is changing on 27 August 2026, and one that is not. A new instrument, S.I. 2026/896, amends Part 14 of the same Order with effect from 27 August 2026. We read it in full. It amends Class A and Class B, which cover solar on domestic premises, and the interpretation paragraph. It does not amend Class G and it does not change any heat pump rule. The words “heat pump”, “air source” and “ground source” do not appear anywhere in the instrument.
One qualification, for completeness, because it is the single place the change reaches past solar. Article 5 amends paragraph P, which is the interpretation paragraph for the whole of Part 14, and inserts a definition of “roof enclosure”, which “includes any balustrade, railing, parapet or other enclosure installed on the roof of a building”. Being in the shared interpretation paragraph, that definition is available to every class in Part 14 rather than to the solar classes alone. It defines a term; it does not alter any heat pump limit or condition.
If you are looking at solar as well, the change is relevant to that and we cover it on our planning and costs hub.
Sources: The Town and Country Planning (General Permitted Development) (England) (Amendment) Order 2026, S.I. 2026/896, made 29 July 2026, in force 27 August 2026, articles 2 to 6 and Explanatory Note, checked 17 August 2026, https://www.legislation.gov.uk/uksi/2026/896/made; article 5, amendment of paragraph P (interpretation of Part 14), checked 18 August 2026, https://www.legislation.gov.uk/uksi/2026/896/article/5/made
So what should you do first?
There is no universal order, but there is a sensible default.
- Find out how much heat the building loses, before you look at any product. Everything else is downstream of that number.
- Do the cheap fabric work that is obviously outstanding, such as loft insulation and draught proofing, because it reduces the size of everything you buy afterwards.
- Establish what your electrical supply can carry, especially if an EV charger, solar or a battery is anywhere in your plans.
- Then get heat pump quotations, from more than one MCS certified installer, each based on a survey and a heat loss calculation rather than a floor area.
- Read the grant rules yourself on GOV.UK and Ofgem, on the day you need them, rather than trusting any summary, including this one.
If that sequence means a heat pump is two or three years away for your property, that is a real answer and a useful one. It is not the same as “no”.
Where to check things yourself:
- Government heat pump check: https://www.heat-pump-check.service.gov.uk/
- Apply for the Boiler Upgrade Scheme: https://www.gov.uk/apply-boiler-upgrade-scheme
- Ofgem, Boiler Upgrade Scheme: https://www.ofgem.gov.uk/environmental-and-social-schemes/boiler-upgrade-scheme-bus
- Find an MCS certified installer: https://mcscertified.com/find-an-installer/
- Find ways to save energy in your home: https://www.gov.uk/improve-energy-efficiency
- Find your local council, for the planning position on your property: https://www.gov.uk/find-local-council
If you are in Scotland, GOV.UK directs you to Home Energy Scotland for loans and grants rather than the Boiler Upgrade Scheme. The Boiler Replacement Scheme in Northern Ireland is closed, and GOV.UK points to nidirect for energy saving grants there instead.
Source: GOV.UK, “Apply for the Boiler Upgrade Scheme”, overview. Checked 17 August 2026.
Two of the questions above have pages of their own, because they are the ones that decide most conversations. Will you need new radiators sets out the published method for working that out room by room. And if the property is off the gas grid on oil or LPG, the £9,000 grant and the date it ends is worth reading before you plan the timing.
Where our knowledge ends
We would rather tell you what we are not than make a claim we cannot stand behind.
Eco Connect is an independent advisory business. We do not install heat pumps, we do not size or specify them, we do not perform MCS heat loss calculations, we hold no installation accreditation, and we cannot apply for the Boiler Upgrade Scheme on your behalf. Where installation work is appropriate, it is carried out by a vetted delivery partner, and the final technical advice and the quotation sit with them.
We cannot tell you whether Ofgem will approve a particular application. We cannot tell you what your local planning authority will decide. We cannot tell you what a heat pump will cost you to run, because that depends on your building, your tariff and how you live in it. A national average quoted at your house is not information.
What we can do is look at the property with you, work out what is losing heat and what the electrics can carry, and tell you honestly what should happen first. Sometimes that is a heat pump. More often, at least for now, it is something else.
Information and source control
Information correct as of: 17 August 2026.
Grant values, eligibility rules and permitted development rules change. Every rule and figure on this page is dated and linked to the GOV.UK, Ofgem or legislation.gov.uk source it was taken from. Check the source before you rely on it. Boiler Upgrade Scheme values in particular were verified against Ofgem’s version 5.1 property owner guidance, published 2 July 2026, and against GOV.UK on 17 August 2026.
