ECO5 vs Boiler Upgrade Scheme: Which Grant Is Right for You?

The UK government offers two principal schemes to help homeowners improve their property’s energy efficiency and decarbonise their heating: the Energy Company Obligation (ECO5) and the Boiler Upgrade Scheme (BUS). While both aim to create warmer, cheaper-to-run homes, they target different homeowners and fund different levels of work. Deciding which avenue is right for you requires understanding their core eligibility criteria and priorities.

Scheme One: The ECO5 Whole-House Approach

The ECO5 scheme, running until March 2026, is specifically designed as a measure to tackle fuel poverty. Its funding comes directly from major UK energy suppliers, who are obligated to deliver energy efficiency improvements primarily to low-income and vulnerable households. The key characteristic of ECO5 is its comprehensive ‘whole-house’ approach.

The team at So Eco understands that navigating this landscape can be confusing. Do you qualify for a free, whole-house retrofit, or are you looking for a fixed grant to simply help you switch to a heat pump? Let’s break down the fundamental differences between these options so you can make an informed choice and access the right UK energy grants.

Who is ECO5 Designed to Help?

Eligibility for ECO5 is driven by two main factors: the financial status of the occupants and the current energy efficiency of the property.

1. Occupant Eligibility (Income-Based): To qualify for the deepest, most beneficial funding, someone in the household must typically be receiving one of the specified means-tested benefits. This list includes Universal Credit, Pension Credit, Housing Benefit, and various tax credits. For households that don’t receive these benefits, local authorities can use the ECO5 Flex system to nominate residents based on low income (generally below gross annual income) or vulnerability to cold.
2. Property Eligibility (EPC Focus): The ECO5 scheme heavily prioritises properties with low Energy Performance Certificate (EPC rating) scores, typically E, F, or G. The central goal of every ECO5 project is to upgrade the home to a minimum of EPC Band C.

The ‘Fabric First’ Requirement

ECO5 follows a strict “fabric first” rule. This means that if your home needs insulation (such as loft insulation or cavity wall insulation), those measures must be installed before a new heating system, like a heat pump, can be considered. The scheme’s funding covers a wide range of improvements, often at 100% cost:

• Insulation (Loft, Cavity, Solid Wall, Room in Roof)
• First-Time Central Heating (if the home currently lacks it)
• Air Source Heat Pumps and other low-carbon heating systems
• Solar PV systems (Solar panels), when installed as part of a deeper package.

Scheme Two: The Boiler Upgrade Scheme (BUS) Focus

The Boiler Upgrade Scheme is a different type of initiative, designed not to tackle fuel poverty, but to accelerate the decarbonisation of heat across England and Wales. It is a simple, upfront capital grant that helps all eligible property owners afford the transition from fossil fuel boilers to low-carbon heating technology.

BUS Grant Values and Technology

The BUS operates using fixed grant amounts that are deducted directly from the installer’s quote, meaning you only pay the remainder. Grants are set at £7,500 for Air Source Heat Pumps (ASHP) and Ground Source Heat Pumps (GSHP), and £5,000 for Biomass Boilers.

Crucially, the BUS does not fund repairs or replacements for existing gas or oil boilers. Its sole purpose is to encourage the adoption of renewable heating.

Who is Eligible for BUS?

Unlike ECO5, the BUS has no income or benefits restrictions. Eligibility is based purely on the property, its existing heating system, and its ownership status.

• Ownership: You must own your property (including being a private landlord).
• Property Location: Must be in England or Wales (Scotland and Northern Ireland have separate, equivalent schemes).
• System Replacement: You must be replacing an existing fossil fuel heating system (gas, oil, or electric) or a non-efficient system.
• EPC Requirement: While there is no minimum EPC band required, if your home has any recommendations for loft or cavity wall insulation on its current EPC, these must be addressed before the heat pump can be commissioned.

Direct Comparison: ECO5 vs Boiler Upgrade Scheme Compare UK energy grants

When you set the two schemes side-by-side, their differing philosophies become clear. The main consideration in any ECO5 vs boiler upgrade scheme compare UK energy grants discussion, is whether your eligibility is driven by income (ECO5) or technology choice (BUS).

Key Differences Summarised:

• Main Goal: ECO5 aims to tackle fuel poverty through whole-house energy efficiency, whereas the BUS is focused purely on decarbonisation and promoting low-carbon heating technology.
• Eligibility Driver: ECO5 is driven by means-tested benefits or low-income status (ECO5 Flex). The BUS is driven by property ownership and the type of technology being installed.
• Cost to Homeowner: ECO5 is often 100% funded (free). The BUS offers a fixed grant amount (£7,500 for heat pumps), and the homeowner pays the remainder.
• Core Measures: ECO5’s measures include Insulation (mandatory), Heat Pumps, Solar PV, and First-Time Central Heating. The BUS only covers Air Source Heat Pumps, Ground Source Heat Pumps, and certain Biomass Boilers.
• EPC Focus: ECO5 prioritises homes with a D-G rating, aiming to upgrade them to Band C. The BUS requires a valid EPC and any outstanding insulation measures to be fixed before commissioning.
• Installer Role: Under ECO5, the installer determines the package required to hit the EPC target. Under the BUS, the installer applies for the fixed voucher on the owner’s behalf.

Financial Differences: Funding Depth

The biggest distinction lies in the financial scope. ECO5 offers what is effectively a full retrofit package, meaning your total costs can be completely covered, often exceeding £10,000 in value, especially if solid wall insulation is required.

In contrast, the BUS offers a fixed discount of £7,500. While this is a substantial sum, if your total heat pump installation costs £13,000, you would still be required to pay the remaining £5,500 yourself. However, for a homeowner who doesn’t qualify for ECO5 but wants to install a heat pump, the BUS makes the switch significantly more affordable.

Choosing the Right Pathway

Your decision should be based on a simple flow: first, check your eligibility for ECO5. If you do, that scheme offers the highest level of comprehensive support. If you don’t, but still want to install a heat pump, the BUS is your ideal choice.

Choose ECO5 If…

• You or someone in your home receives a qualifying benefit or falls under the low-income threshold for ECO5 Flex.
• Your home has a poor EPC rating (D, E, F, or G) and requires fundamental insulation measures like cavity wall or solid wall insulation to become efficient.
• You require a full package of measures and cannot afford any contribution towards the work.
• You want to explore options like a first-time central heating system or solar PV alongside other measures.

Choose BUS If…

• You do not qualify for ECO5 due to your household income or benefits status.
• You are primarily interested in upgrading your existing heating system to a low-carbon technology like an Air Source Heat Pump.
• Your home is already reasonably insulated, or you are willing to pay for any required insulation upgrades yourself to meet the grant’s requirements.
• You are ready to pay the difference between the grant amount and the total installation cost.

Can I Combine ECO5 and BUS?

No, you cannot use both schemes to fund the same piece of equipment (for example, getting £7,500 from BUS and then further funding from ECO5 for the same heat pump). However, you can certainly use different UK energy grants for different measures in your home.

For instance, you could receive a grant through the Great British Insulation Scheme (GBIS) or the ECO5 Flexible Eligibility (if you meet certain local council criteria) for insulation funding, and then apply for the BUS grant for your heat pump. You just need to ensure the funding for the renewable heating system comes from a single source.

A homeowner might find that they meet the criteria for ECO5, but if they only need a heat pump and their installer determines the ECO5 obligations are complex, they might choose the BUS for a faster, simpler application route, even if it means covering a smaller portion of the cost themselves.

Understanding whether you qualify for the comprehensive, no-cost whole-house improvement offered by ECO5, or the fixed, technology-focused grant of the BUS, is the vital first step. For comprehensive guidance on both schemes, start by visiting So Eco. Let us help you navigate the ECO5 vs boiler upgrade scheme compare UK energy grants options.