Boiler Upgrade Scheme Requirements Explained | 2026 Guide
Check Your Eligibility for Boiler Upgrade Scheme (BUS)
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Quick Answer: What Are the Boiler Upgrade Scheme Requirements?
To qualify, the property must be in England or Wales and you must own it. For most retrofits, the new system must replace fossil-fuel heating or eligible electric heating that does not already include a heat pump.
The installation must use an eligible heat pump or biomass boiler, meet current technical and MCS requirements and be installed through an MCS-certified installer. Social housing and most new builds are excluded. A valid EPC is no longer compulsory for applications properly made from 28 April 2026, although alternative evidence may be needed. Your installer applies to Ofgem and must pass the grant on as an upfront discount.
Boiler Upgrade Scheme Requirements Explained: 2026 Eligibility Checklist
The Boiler Upgrade Scheme (BUS) can reduce the upfront cost of replacing eligible fossil-fuel or electric heating with an approved low-carbon system in England or Wales. However, your property, existing heating, new system, installer and application must all meet the rules.
The requirements changed in 2026. A valid EPC stopped being compulsory for applications properly made from 28 April 2026, while a temporary £9,000 grant became available to certain off-gas homes from 21 July 2026.
This guide focuses on the eligibility checks to make before requesting quotes. For a separate summary of grant changes, see our Boiler Upgrade Scheme 2026 updates guide.
If your property looks eligible, compare quotations from MCS-certified installers after a proper property assessment.
Boiler Upgrade Scheme Requirements at a Glance
| Requirement | What it means |
|---|---|
| Location | Property in England or Wales. |
| Ownership | You own the property and become legal owner of the funded system. |
| Existing heating | Most retrofits replace fossil-fuel or eligible electric heating without a heat pump. |
| Property type | Private homes, rentals, second homes and many non-domestic buildings can qualify; social housing and most new builds cannot. |
| Installer | Must hold suitable MCS certification. |
| New system | Must be an eligible technology meeting current technical standards. |
| Public funding | The same installation cannot have prohibited public funding or ECO support. |
| Grant process | Installer applies and deducts the full grant upfront. |
These requirements are summarised from the current Ofgem Boiler Upgrade Scheme guidance for property owners and installer requirements.
1. You Must Own an Eligible Property in England or Wales
BUS covers eligible residential and non-residential properties in England and Wales. Owner-occupiers, private landlords, second-home owners and businesses that own qualifying buildings can potentially use it. Air-to-air heat pumps are an exception because BUS support for them applies to residential properties only.
Tenants cannot apply independently. The property owner must also become the legal owner of the funded heat pump or biomass boiler after installation. Some finance arrangements can qualify, provided ownership transfers to the property owner.
Social housing is excluded. Most new builds are excluded too, although qualifying self-builds can receive heat-pump support. An eligible self-build must broadly have been built using the first owner’s labour or resources, never have been owned by a business or organisation and not form part of an excluded property development.
2. Your Existing Heating System Must Qualify
For a normal retrofit, BUS must replace an existing fossil-fuel or qualifying electric heating system.
Gas, oil, LPG and coal can qualify. Electric systems such as storage heaters, panel radiators and electric boilers can also qualify. This is important because an all-electric property is not automatically excluded from BUS.
However, BUS cannot normally fund replacement of an existing heat pump that already provides space heating. Keep evidence of the old system because Ofgem may request photographs, bills, receipts or other records.
If you are comparing a heat pump with your current boiler, our air source heat pump vs gas boiler guide covers the practical differences.
3. The New Technology Must Be BUS-Eligible
Current BUS support covers air-to-water, air-to-air, ground or water source heat pumps, eligible shared-ground-loop systems and biomass boilers.
| Technology | 2026 grant | Key restriction |
|---|---|---|
| Air-to-water heat pump | £7,500 | £9,000 may apply to qualifying off-gas oil/LPG replacements until 31 March 2027. |
| Ground/water source heat pump | £7,500 | Same temporary £9,000 uplift may apply. |
| Air-to-air heat pump | £2,500 | Residential properties only. |
| Biomass boiler | £5,000 | Rural, off-gas properties only, with extra rules. |
Current grant categories and values took effect on 21 July 2026.
Fossil-fuel hybrid systems are not eligible. Since April 2026, however, a BUS heat pump can work alongside qualifying non-fossil supplementary appliances, including direct electric heating, storage heaters, immersion heaters and other permitted technologies.
Our air source vs ground source heat pump guide explains how the two main wet-system options differ.
4. Do You Need an EPC in 2026?
No. A valid Energy Performance Certificate is no longer a mandatory BUS requirement for applications properly made from 28 April 2026.
If the property has a valid EPC, the installer must provide its certificate number. Without one, the installer provides alternative evidence. Ofgem says this can include a recent utility bill or fuel receipt, photographs of the existing heating system and an expired EPC number where available. Other evidence can be considered case by case.
Insulation is still worth considering because lower heat loss can improve comfort and heat-pump performance, but the absence of a valid EPC does not automatically prevent a BUS application. Ofgem recommends considering practical energy-efficiency improvements rather than making them a blanket BUS eligibility condition.
5. The Heat Pump Must Meet Technical Requirements
The complete installation must comply with BUS and approved MCS standards. The government publishes the standards approved for the Boiler Upgrade Scheme.
A BUS-funded heat pump must be sized to meet the property’s full space-heating requirement. The overall arrangement must also meet space-heating and hot-water demand, either through the funded heat pump or permitted supplementary non-fossil equipment.
Air-to-water and ground source heat pumps need a minimum seasonal coefficient of performance, or SCOP, of 2.8. Individual systems are generally capped at 45kWth, qualifying cascade systems at 70kWth and shared ground loops at 300kWth combined.
The product must meet approved standards, but appearing on Ofgem’s Boiler Upgrade Scheme Product Eligibility List does not guarantee that the whole installation qualifies. Ofgem explicitly notes that other project-specific requirements still apply.
For the technology itself, our guide to how air source heat pumps work explains the heating cycle separately.
6. Extra Rules Apply to the £9,000 Off-Gas Grant
From 21 July 2026 to 31 March 2027, qualifying off-gas properties can receive £9,000 towards an air-to-water or ground source heat pump when replacing oil or LPG heating.
The property must meet Ofgem’s off-gas definition. It must not be heated by mains gas, have a record of an existing gas meter point, be attached to a heat network or be a new-build property. A capped or clamped gas meter does not automatically make a property off-grid.
Other eligible heating replacements may still receive the standard grant, but not necessarily the £9,000 uplift.
7. Biomass Boilers Have Stricter Requirements
Biomass receives £5,000 only in limited situations. The property must be rural and must not be, or previously have been, connected to the gas grid. The boiler must meet the full space- and water-heating needs as a standalone system and satisfy applicable emissions and technical requirements.
Biomass is not BUS-eligible for qualifying self-build properties.
8. Your Installer Applies and Passes on the Grant
BUS is installer-led. Your MCS-certified installer submits the voucher application to Ofgem. Ofgem then contacts you to confirm consent and relevant eligibility details.
The full grant must be deducted upfront from the quote and shown on the final invoice. You should not pay the grant amount and then reclaim it yourself.
Where Ofgem issues a voucher before installation, it is normally valid for three months, or six months for a ground source heat pump. Current guidance also allows some retrospective applications, but the application must be properly made within 120 days of commissioning.
Common Reasons BUS Eligibility Can Fail
Common problems include an ineligible property, replacing an existing heat pump, using a fossil-fuel hybrid, choosing a non-compliant system, using an installer without the required MCS status or receiving prohibited public funding for the same installation.
An eligible property or product is not enough on its own. The property, old heating system, new system, installer and application must satisfy the rules together.
Pre-Application Checklist
- Confirm ownership and that the property is in England or Wales.
- Identify and photograph the heating system being replaced.
- Check the property is not in an excluded category.
- Confirm the proposed technology is BUS-eligible.
- Check the installer’s MCS certification.
- Ask what EPC or alternative evidence will be used.
- Check whether the £9,000 off-gas uplift applies.
- Make sure the grant is deducted from the quotation.
- Ask how the system meets heat-loss, capacity and SCOP requirements.
- Compare likely running costs as well as upfront cost. Our air source heat pump running costs guide explains the main variables.
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Frequently asked questions
Find clear answers to common questions about Boiler Upgrade Scheme eligibility, including landlords, businesses, second homes, EPCs, insulation, existing heating systems, self-builds, air-to-air heat pumps, biomass and the £9,000 grant.
Property owners in England and Wales may qualify if their property, existing heating system, proposed technology and installation meet BUS rules. Private landlords, second-home owners and some businesses can qualify.
Yes. A private landlord can potentially use BUS for a property they own, provided the installation meets the normal eligibility requirements.
Some non-residential properties can qualify for air-to-water or ground source heat pumps and biomass boilers. Air-to-air BUS grants are limited to residential properties.
Yes. Ofgem lists second homes and holiday homes among examples of property types that can potentially qualify.
Not independently. The property owner must be involved and must own the BUS-funded heating system after installation.
No. A valid EPC is no longer compulsory for applications properly made from 28 April 2026. If no valid EPC exists, alternative evidence is required.
Not as a blanket BUS eligibility requirement. However, insulation can reduce heat loss and may improve heat-pump performance and running costs.
Yes, potentially. Current Ofgem guidance specifically identifies storage heaters, electric panel radiators and electric boilers as examples of qualifying electric heating systems.
Normally no. If the existing system already includes a heat pump providing space heating, the property is generally not eligible for BUS funding for its replacement.
Qualifying self-builds can receive BUS support for heat pumps. They must meet specific ownership and development requirements. Biomass boilers are not eligible in self-builds.
Yes. Current BUS rules provide £2,500 for eligible air-to-air heat pumps in residential properties.
Not as a fossil-fuel hybrid system. BUS does allow permitted supplementary non-fossil heating appliances under the 2026 rules.
The temporary £9,000 grant applies to qualifying off-gas-grid properties replacing oil or LPG heating with an eligible air-to-water or ground source heat pump. It is available under current rules until 31 March 2027.
Potentially, but the property must meet stricter conditions, including being rural and off the gas grid. The biomass boiler must also satisfy technical and emissions requirements.
No. The scheme is installer-led. Your MCS-certified installer submits the application, and Ofgem contacts you to confirm consent and relevant details.
Conclusion:
The Boiler Upgrade Scheme requirements are a chain of checks: eligible property, qualifying existing heating, approved low-carbon system, compliant technical design, MCS-certified installer and correctly submitted application.
The 2026 rules removed the mandatory valid-EPC requirement, but special conditions still apply to self-builds, biomass, air-to-air systems and the temporary £9,000 off-gas grant.
If the basic requirements fit your property, compare properly surveyed quotes before committing. The quotation should show the BUS discount clearly and explain the full installed cost, not just the headline grant.
