Whole-House Retrofit Schemes: Complete Home Energy Upgrade
A whole-house retrofit scheme (such as ECO4 or HUG2) is a government-backed programme that manages your entire home energy upgrade from start to finish. Instead of hiring separate contractors for insulation, heat pumps, solar panels, and windows, the scheme handles everything — including the grant and funding paperwork.
Whole-house retrofit schemes can access higher funding rates than individual grants, making deep retrofits more affordable. Total funding through a whole-house retrofit scheme can reach £10,000–£25,000+ for a comprehensive upgrade.
Last updated March 2026
Fact-checked by John Rooney, Solar Energy Editor. Editorial policy
Quick Answer
A whole-house retrofit scheme (ECO4, HUG2) manages your entire home energy upgrade — insulation, heat pump, solar, windows, and funding paperwork — through a single contractor. These schemes access higher funding rates than individual grants, with total support reaching £10,000–£25,000+ for a comprehensive retrofit.
What does a whole-house retrofit scheme do?
A whole-house retrofit scheme provides a complete end-to-end home energy upgrade service:
Home assessment
Full energy assessment including EPC, heat loss calculation, and upgrade roadmap.
Design and planning
Detailed plan for insulation, heating, solar, and ventilation upgrades.
Funding management
Handle all grant applications and paperwork on your behalf (ECO4, HUG2, BUS).
Contractor coordination
Manage all tradespeople (insulation, plumbing, electrical, roofing).
Quality assurance
PAS 2035-audited quality standards, post-installation inspections.
Post-upgrade EPC
New EPC assessment to confirm the improvement achieved.
The key difference: a whole-house retrofit scheme takes responsibility for the whole project. You deal with one company instead of 4–6 separate contractors. They guarantee the result — typically a minimum 2-grade EPC improvement.
How does the whole-house retrofit process work?
- Contact a registered retrofit coordinator for a home assessment (free or low cost)
- The coordinator surveys your home and creates an upgrade plan
- You receive a detailed quote showing costs, funding, and expected EPC improvement
- You agree to the plan and sign a contract
- The coordinator applies for funding (ECO4, HUG2, BUS) on your behalf
- Works are scheduled and carried out (typically 2–6 weeks depending on scope)
- Post-installation inspection and EPC assessment
- Funding is paid directly to the installer (you pay only the net cost)
Important: With a whole-house retrofit scheme, the funding is usually paid directly to the company, so you only pay the difference. This reduces your upfront cost significantly.
Whole-house retrofit funding rates
Whole-house retrofit schemes can access enhanced funding rates compared to individual grants:
| Upgrade | Individual Grant | Whole-House Scheme Funding | Difference |
|---|---|---|---|
| Loft insulation | £300–£500 | Fully funded | Covered |
| Cavity wall insulation | £300–£500 | Fully funded | Covered |
| External wall insulation | £4,000–£6,000 | Up to £10,000 | +£4,000 |
| Internal wall insulation | £2,500–£4,000 | Up to £6,000 | +£2,000 |
| Heat pump system (BUS) | Up to £7,500 | Up to £7,500 | Same |
| Solar PV | Up to £1,500 | Up to £2,000 | +£500 |
| Windows/doors | Not available individually | Up to £3,000 | +£3,000 |
| MVHR | £1,500 | £1,500 | Same |
Total funding through a whole-house retrofit scheme can reach £10,000–£25,000+ for a deep retrofit, compared to £7,500–£12,000 through individual grants. The enhanced rates are designed to encourage comprehensive whole-house upgrades. The scheme typically requires a minimum EPC improvement (typically to C or better) to access the enhanced rates. See our EPC upgrades guide.
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Get a Quote ↓Benefits of using a whole-house retrofit scheme
Benefits
- Single point of contact for the entire project
- Higher funding rates (up to 50% more on some measures)
- Professional project management
- PAS 2035 quality assurance and auditing
- Guaranteed EPC improvement
- Reduced hassle — no coordinating multiple contractors
- Funding paperwork handled for you
- Often better pricing through bulk purchasing
Considerations
- Less control over individual contractors
- May cost slightly more than DIY-coordinated upgrades
- Availability varies by region
- Must commit to a comprehensive upgrade (not single measures)
- Waiting times can be 3–6 months in busy periods
How to choose a whole-house retrofit provider
Check TrustMark registration
Only use companies registered with TrustMark and compliant with PAS 2035.
Get multiple quotes
Compare at least 3 providers for your project.
Check references
Ask for examples of completed projects in your area.
Understand the scope
Make sure the quote covers everything including making good.
Payment terms
Confirm the funding is deducted upfront (you shouldn't pay it and wait).
Timeline
Get a clear project timeline with milestones.
Find registered retrofit providers
Visit the official TrustMark register: trustmark.org.uk/find-a-tradesperson
Whole-house retrofit providers in the UK
There are many TrustMark-registered retrofit providers across the UK. Here are some of the main providers:
| Provider | Areas Served |
|---|---|
| E.ON Energy Solutions | Nationwide |
| British Gas (Centrica) | Nationwide |
| OVO Energy Services | Nationwide |
| Elmhurst Energy | Nationwide |
| Engie | Nationwide |
| Sero Energy | Wales and South West England |
| RetrofitWorks | London, South East, East |
| Everwarm | Scotland, North East England |
| Warmworks | Scotland |
| Yes Energy Solutions | Yorkshire, North East, North West |
| GreenSquareAccord | Midlands, South West |
| Sustainable Building Services | South East England |
This is not an exhaustive list. The full searchable list is available on the TrustMark website. Always verify TrustMark registration before engaging a provider.
Typical whole-house retrofit costs
A whole-house retrofit is a significant investment, but enhanced funding makes it considerably more affordable. Here are typical costs by property type:
| Property Type | Total Cost | Scheme Funding | Net Cost | Typical EPC Improvement |
|---|---|---|---|---|
| Flat | £20,000–£30,000 | £8,000–£15,000 | £12,000–£18,000 | D→B |
| Mid-terrace | £25,000–£35,000 | £10,000–£18,000 | £15,000–£20,000 | D→B |
| Semi-detached | £30,000–£45,000 | £12,000–£22,000 | £18,000–£25,000 | D→B |
| Detached | £40,000–£55,000 | £15,000–£25,000 | £25,000–£35,000 | D→B |
Important: The retrofit scheme deducts the funding from your invoice upfront. You only pay the net cost. This is a major advantage over the individual grant route, where you may pay the full amount and reclaim the grant afterwards.
What's included in a typical retrofit?
A whole-house retrofit is a comprehensive upgrade. A typical package includes:
Wall insulation
External or internal insulation to reduce heat loss through walls — the single biggest source of heat loss in UK homes.
Loft insulation
Top-up or replacement of loft insulation to 300mm+ to meet current standards.
Heat pump
Air-to-water or ground-source heat pump replacing oil/gas boiler. BUS grant up to £7,500.
Windows & doors
Double or triple-glazed windows and insulated doors. Major impact on comfort and airtightness.
Ventilation (MVHR)
Mechanical ventilation with heat recovery. Essential in airtight homes to maintain air quality.
Solar PV
Solar panels to generate electricity and further improve the EPC rating. Enhanced scheme funding up to £2,000.
Whole-house scheme vs individual grants: which route?
| Feature | Whole-House Scheme | Individual Grants |
|---|---|---|
| Best for | Comprehensive upgrades (3+ measures) | Single measures (e.g. just loft insulation) |
| Funding rates | Higher on wall insulation, windows, solar | Standard rates |
| Total funding possible | Up to £25,000+ | Up to £12,000 |
| Funding payment | Deducted from invoice upfront | You may pay full cost, reclaim later |
| Project management | Included (one point of contact) | You coordinate contractors |
| EPC requirement | Must achieve C or better | No minimum EPC required |
| Flexibility | Must commit to comprehensive package | Mix and match individual measures |
| Wait times | 3–6 months typical | Book contractors individually |
Our recommendation: If your home needs 3 or more upgrades (e.g. insulation + heat pump + windows), a whole-house retrofit scheme is usually the better route. You get higher funding, professional project management, and a guaranteed result. For a single measure like loft insulation or solar panels, individual grants are simpler. See our EPC upgrades guide for which measures give the biggest improvement.
What's new for whole-house retrofit schemes in 2026
- Boiler Upgrade Scheme extended — £7,500 grants for heat pumps continue
- ECO4 scheme continues — energy suppliers obligated to fund improvements for low-income and vulnerable households
- HUG2 (Home Upgrade Grant) — local authority-delivered funding for off-gas-grid homes with low EPC ratings
- Great British Insulation Scheme — single-measure insulation support for homes in Council Tax bands A–D
- PAS 2035 compliance required — all ECO4 and HUG2 projects must follow the PAS 2035 whole-house retrofit framework
Whole-House Retrofit FAQ
What is a whole-house retrofit scheme?
A government-backed programme (such as ECO4 or HUG2) that manages your entire home energy upgrade. They handle assessment, design, contractor coordination, funding applications, and quality assurance. You deal with one company instead of multiple contractors.
Is whole-house scheme funding higher than individual grants?
Yes. Whole-house retrofit schemes can access enhanced funding rates for certain measures (external wall insulation, windows, solar PV). Total funding can be £5,000–£10,000 higher than applying for individual grants separately.
How much does a whole-house retrofit cost?
A typical whole-house retrofit costs £20,000–£55,000 before funding, depending on the home's size and condition. After enhanced scheme funding, the net cost is typically £12,000–£35,000.
How long does a whole-house retrofit take?
From initial assessment to completion, expect 3–6 months. The actual construction work typically takes 2–6 weeks. Waiting times for availability can add another 2–3 months.
Do I need to move out during the upgrade?
Usually not. Most work can be done while you live in the house, though there will be disruption. External wall insulation and window replacement cause the most disturbance.
Can I choose which upgrades to include?
The retrofit coordinator will recommend a package based on your home's needs. To access enhanced funding rates, a minimum EPC improvement is required (typically to C or better). You can discuss priorities but individual measure cherry-picking defeats the purpose.
What if I only want solar panels or a heat pump?
For individual measures, you don't need a whole-house scheme. Apply for individual grants through an MCS-certified contractor. A whole-house scheme is best for comprehensive upgrades involving 3+ measures. See our solar grants guide for individual grants.
Related Guides
Home Insulation
Loft, cavity wall, and solid wall insulation: costs, grants, and savings.
EPC Upgrades
Improve your EPC rating. Costs, grants, and property value impact.
Heat Pumps
Air source & ground source heat pumps: costs, BUS grant up to £7,500.
ECO4 Scheme
ECO4 eligibility, free measures, how to apply, and common scams to avoid.
Sources
- Gov.uk: Boiler Upgrade Scheme
- Ofgem: Energy Company Obligation (ECO4)
- Gov.uk: Home Upgrade Grant (HUG2)
Last updated: March 2026
John Rooney is the founder of Solar Info and has been covering the UK solar energy market since 2023. He fact-checks all content against official MCS and Ofgem data and maintains relationships with MCS-certified installers across the UK.
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