# Nest and Warm Homes, Welsh energy efficiency schemes
This guide walks you through how Nest and the wider Warm Homes programmes work in Wales, how they differ from ECO4 and HUG2 in England, and what you need to do as an installer to get a slice of that work. It's written for builders, plumbers and retrofit installers who are already doing energy-efficiency work (or ECO4) and want to plug into Welsh schemes without getting lost in the acronyms.
Quick rule of thumb: if you're PAS- and TrustMark-ready for ECO4, you've got the technical ticket for Welsh Warm Homes/Nest: but you still need to get onto their installer list or framework, and you'll be working to Welsh rules and fuel-poverty goals, not just ECO points.
1. How Wales does it differently
In Wales, Warm Homes is the Welsh Government's main tool for tackling fuel poverty and upgrading cold, leaky homes. The current setup is:
- A national Warm Homes / Nest scheme for private households, run on behalf of Welsh Government.
- Separate pots like the Optimised Retrofit Programme (ORP) for social housing, still focused on affordable warmth and decarbonisation.
Compared to ECO4 and HUG2 in England:
- ECO4 is funded and delivered by energy suppliers, working to Ofgem rules. Warm Homes/Nest is Welsh Government funded and delivered via a contracted scheme manager.
- ECO4/HUG2 run to UK-wide rules. Warm Homes has Welsh-specific eligibility tweaks, funding caps and decarbonisation priorities, and must align with the Well-being of Future Generations goals.
For you as a tradesperson, it means you're not just dealing with suppliers, you're dealing with a Welsh Government programme and its delivery partner, with their own installer lists and quality rules.
Tip for new starters Think of ECO4 as "supplier money under Ofgem rules" and Warm Homes/Nest as "Welsh Government money under Welsh rules", same kind of work, different bosses.
2. Who qualifies, Nest / Warm Homes eligibility
The Nest route under Warm Homes is aimed squarely at low-income, hard-to-heat homes in the private sector.
Tenure: homeowners or private renters, not council or housing-association tenants (they're usually helped via social landlords and ORP).
Income: either on specific means-tested benefits (for example, Universal Credit, Pension Credit, Income Support, income-based JSA/ESA, Housing Benefit, Council Tax Reduction, Working/Child Tax Credit with income below set limits), or living in a low-income household under Nest's income thresholds, Welsh Government publishes tables with weekly, monthly and annual income caps based on household size.
Property energy efficiency:
- Standard route · EPC E or below (score ≤54).
- Health route · EPC D or below (score ≤68) where someone has a qualifying health condition.
Health route: separate channel for people on low income with specified conditions (respiratory disease, circulatory disease, certain mental health conditions, dementia and learning disabilities). Recent figures show thousands of homes assessed under the health route, with only a chunk passing both health and income checks. That's your target customer group on Nest: low income, poor EPC, and often vulnerable.
Tip for new starters When a domestic customer mentions Nest, always ask three quick questions: "Own or privately rent? What's your EPC roughly? On any means-tested benefits or serious health conditions?", that tells you fast if it's worth a Nest referral.
3. What work is funded, measures and depth
Warm Homes/Nest funds a mix of fabric, heating and sometimes renewables, similar to ECO4 but under Welsh policy priorities.
Typical Nest/Warm Homes measures include:
- Insulation · loft, cavity wall, internal/external wall, underfloor, room-in-roof where suitable.
- Heating upgrades · boiler replacements, modern efficient heating systems, controls, sometimes full system upgrades for homes with broken or very inefficient systems.
- Crisis interventions · for households with no heating/hot water, Nest can fast-track simple measures to get them warm and safe again.
- Renewables/low-carbon · as Warm Homes policy shifts towards decarbonisation, more emphasis on technologies like heat pumps and solar is expected, especially in the new Warm Homes Plan Wales is developing.
Recent reporting says:
- Retrofit upgrades under the new Warm Homes Nest scheme cut fuel bills by around £570 per year, and crisis interventions by about £578 per year on average, with significant projected carbon savings.
- Welsh Government's 2025–26 budget puts about £37.5m capital into Warm Homes, up 7% on the year before, but the Senedd research service still calls this short of what's needed to tackle fuel poverty at scale.
In practice, the scheme tends to fund whole-house packages up to a per-home cap rather than just one cheap measure.
Tip for new starters Expect Nest jobs to be full retrofit packages with lots of paperwork, not "bung in a quick boiler and disappear", price your time (and patience) accordingly if you're subbing in on them.
4. How Nest / Warm Homes differs from ECO4 and HUG2
| ECO4 (England/GB) | Warm Homes / Nest (Wales) | |
|---|---|---|
| Who pays | Large energy suppliers; Ofgem oversees | Welsh Government through Warm Homes budget; scheme manager delivers |
| Policy goals | Carbon and obligation targets for suppliers, GB-wide rules | Wales's "primary mechanism to tackle fuel poverty", tied to 2035 fuel poverty targets and well-being goals |
| Design of upgrades | Cost-effective measures meeting ECO scoring rules | Deeper retrofits per property, higher per-home caps, more whole-house thinking |
| Admin | Supplier/Ofgem-driven paperwork | Welsh Government policy alignment, Welsh Housing Quality Standard, Well-being of Future Generations Act goals |
For you, it means you might be doing similar technical work, but the rules, paperwork and grant logic are different, and usually a bit more holistic in Wales.
Tip for new starters If you already do ECO4 work, don't assume the scoring, caps and job structure are the same in Wales, treat each scheme's installer manual as its own rulebook.
5. PAS 2035, PAS 2030 and TrustMark, what's mandatory
For government-backed domestic retrofit, the PAS/TrustMark package is your passport, and Wales follows that same model.
- PAS 2035:2019 · sets out the whole-house retrofit process: roles like Retrofit Assessor, Coordinator, Designer, Installer, handover, monitoring, risk paths, etc.
- PAS 2030:2019 · sets installation requirements for each measure (for example, EWI, CWI, lofts, heating).
- TrustMark · the quality mark all ECO installers must have. To get TrustMark you must be certified to PAS 2030 and comply with PAS 2035, or use MCS where measures fall outside PAS (for example, some renewables).
Welsh schemes follow the same core rules:
- ECO4 in Wales requires TrustMark and PAS 2035/2030 compliance.
- Warm Homes / Warm Homes Plan and ORP expect PAS-compliant retrofit and use TrustMark or equivalent frameworks, especially for owner-occupied and PRS work.
Recent advice for ECO4 installers stresses that projects with handover after March 2025 must be covered under the updated PAS 2023 arrangements for TrustMark lodging, if you're not on the current PAS certificate, your jobs can't be lodged. That applies regardless of whether the house is in Wales or England.
So to work on Warm Homes/Nest in Wales, you should assume you need:
- PAS 2030 certification for the measures you install.
- Access to a Retrofit Coordinator working to PAS 2035.
- Active TrustMark registration (or MCS where applicable).
Tip for new starters If a scheme or main contractor says "Warm Homes / Nest work" and you don't have PAS 2030 + TrustMark, you're either going in as labour only under someone else's badge, or you're not going in at all, get your own accreditation if you want to be the main installer.
6. Can an ECO4 installer in England work on Welsh schemes?
If you're already ECO4-approved in England (PAS-certified and TrustMark-registered), you're most of the way there for Welsh work:
- Your TrustMark and PAS credentials are GB-wide · they're not England-only.
- ECO4 guidance doesn't split standards by country · PAS/TrustMark apply in Wales as well.
But you still need to clear scheme-specific hurdles:
- Warm Homes/Nest and ORP will have their own installer procurement · you may need to win a place on their installer framework, subcontract to the lead scheme manager, or pass a separate approval process.
- Welsh Government programmes expect you to understand and align with Welsh energy policy, Warm Homes rules, and Well-being of Future Generations goals, not just ECO technical standards.
So:
- No, you don't need a totally separate technical accreditation if you're already PAS/TrustMark-compliant · the standards are the same.
- Yes, you still need to sign up or be appointed under the specific Welsh scheme · ECO4 registration alone doesn't automatically list you as a Nest/Warm Homes installer.
Tip for new starters Treat ECO4 accreditation as your "ticket to the dance", but Warm Homes/Nest as a separate contract you still have to win, don't assume the scheme will send you work just because you're on a supplier's ECO list in England.
7. Installer routes, Nest, Warm Homes and ORP
In practice, there are three main ways a tradesperson gets near this work in Wales:
Direct installer for Warm Homes/Nest
You apply to join the scheme manager's installer panel or framework, showing PAS/TrustMark compliance, capacity, insurances and Welsh-specific understanding. They feed you jobs, handle eligibility, and pay you on set rates per measure or per project.
Subcontractor to a main retrofit firm
You don't hold PAS/TrustMark yourself; instead, you work under a main contractor's badge, delivering specific elements (for example, plastering, roof repairs, heating installs) on their Warm Homes jobs. Lower margin but less compliance hassle.
Social housing / ORP route
The Optimised Retrofit Programme funds social landlords to deliver PAS-aligned decarbonisation upgrades to their stock and align with the Welsh Housing Quality Standard. Landlords procure retrofit teams and installers via frameworks that also use PAS 2035, TrustMark/MCS and well-being goals. Warm Homes Plan work will be similar, just under a rebranded structure and possibly with more focus on renewables.
Tip for new starters Decide whether you want to be scheme-facing (hold PAS/TrustMark and deal with audits) or trade-facing (sub to someone who does), both can make money, but they're very different levels of admin.
What to do next
- Check your current status: do you hold PAS 2030 certification for the measures you want to install, and is your TrustMark registration active and updated for the current PAS version?
- Call or email Nest Wales and ask how they're currently onboarding or working with installers (direct panel vs main contractor model) and what accreditations and insurance levels they expect.
- If you're not ready to carry the PAS/TrustMark load yourself, look for retrofit firms in Wales already doing Warm Homes/Nest or ORP work and offer your trade on a subcontract basis while you learn the ropes.
- Read the latest Welsh Warm Homes / Warm Homes Plan updates so you know where the scheme is heading · more deep retrofits, more renewables · and pick training accordingly (for example, heat pumps, fabric first).
Sources
- Welsh Government Warm Homes Nest scheme annual report 2024–25 · new Warm Homes Nest scheme details, health route, eligibility, households helped and average bill savings.
- Welsh Government Nest eligibility page · tenure, benefit-based and income-threshold criteria, EPC cut-offs (E or D with health conditions).
- Senedd Research article on Warm Homes Programme · revised programme from April 2024, funding levels (£37.5m capital 2025–26) and fuel-poverty gap.
- Warm Homes and Energy Conservation Act 2000 · legislation.gov.uk/ukpga/2000/31/contents · fuel poverty duty underpinning Welsh programmes.
- PAS 2035:2019 · whole-house retrofit standard; roles and processes for domestic retrofit.
- PAS 2030:2019 · installation standard for individual measures.
- TrustMark Framework Operating Requirements · PAS 2030 certification and PAS 2035 compliance for ECO and scheme work.
- Welsh Government Optimised Retrofit Programme 3 guidance · PAS-aligned fabric-first retrofit for social housing.
- Well-being of Future Generations (Wales) Act 2015 · legislation.gov.uk/anaw/2015/2/contents · well-being goals influencing Welsh scheme design.
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