The price cap is rising again, but for some households the real cost is measured in damp walls and freezing rooms. A BBC investigation has revealed that residents in properties upgraded under the government’s ECO4 scheme are living in ‘uninhabitable’ homes after installers left insulation work incomplete or dangerously botched. One tenant described mould spreading through a bedroom within weeks of the work, a direct consequence, they say, of a firm that has since folded.
As reported by the BBC, the collapsed energy firm left homeowners with no recourse for repairs. The case is a stark warning for anyone considering ECO4-funded upgrades, free does not mean risk-free.
Who qualifies, and who doesn’t
ECO4 is the fourth phase of the Energy Company Obligation, a government scheme that forces larger energy suppliers to fund insulation, heating, and glazing improvements for low-income and vulnerable households. Eligibility is means-tested: households on certain benefits or with a low income and an EPC rating of D or below can qualify. The scheme is administered by suppliers, but the actual installation is subcontracted to third-party firms.
That subcontracting chain is where the problems start. The BBC’s report highlights a firm that took on ECO4 contracts, did shoddy work, then dissolved, leaving tenants with no legal route to force repairs. The energy supplier that commissioned the work is ultimately responsible, but chasing them can take months.
What it costs a typical 3-bed semi
ECO4 covers the full cost of approved measures, typically cavity wall insulation costs £1,500–£3,000, loft insulation £500–£1,200, and a new boiler or heat pump £5,000–£12,000. For a 3-bed semi, a full package could be worth £8,000–£15,000. But the catch is that the installer is chosen by the energy supplier, not the homeowner. You cannot vet them yourself.
If the work is botched, the immediate cost is not financial, it’s health and comfort. Damp and mould from poorly installed insulation can trigger asthma and other respiratory conditions. The long-term cost is a home that is harder to heat, meaning higher bills. One resident quoted in the BBC report said their energy use actually increased after the work.
How to protect yourself, and what to do if it goes wrong
The Energy Saving Trust advises homeowners to ask for proof of accreditation before any work begins. Installers should be certified under the Microgeneration Certification Scheme (MCS) for heat pumps and solar, or the National Insulation Association (NIA) for insulation. They must also be registered with TrustMark, the government-endorsed quality scheme.
Yet even this is no guarantee. The firm in the BBC story was TrustMark-registered before it collapsed. The real protection is a written contract that includes a clear guarantee, typically 10 years for insulation, and the name of the energy supplier that commissioned the work. If the installer folds, the supplier is still liable. Complaints should go first to the supplier, then to the Energy Ombudsman. Ofgem can also investigate and, in theory, force the supplier to rectify the work.
But the process is slow. The BBC’s affected residents waited months with no resolution. The lesson is to document everything: take photos before and after, keep all correspondence, and get a completion certificate signed off by a qualified surveyor if possible.
The bigger picture: ECO4’s design flaw
The ECO4 scheme is meant to tackle fuel poverty and improve the UK’s notoriously leaky housing stock, 14 million homes have an EPC rating of D or below. But the BBC report exposes a structural weakness: the scheme relies on a chain of contractors with little direct oversight from the energy supplier or Ofgem. When a contractor goes bust, the householder is left holding the damp walls.
Ministers have promised to tighten rules, but no timeline has been given. In the meantime, homeowners should treat any ECO4 offer with healthy scepticism. Ask the supplier for the installer’s full trading history, check Companies House for any signs of financial trouble, and never sign a completion certificate until you are satisfied the work is sound.
If you suspect botched work, contact your energy supplier in writing immediately. Copy Ofgem’s consumer team and your local MP. The Energy Ombudsman can award compensation of up to £10,000, but only if you report within 12 months of the issue arising. Do not wait.
Frequently Asked Questions
No, the energy supplier selects the installer. But you can refuse to proceed if you are not satisfied with their credentials. Ask for proof of MCS or NIA certification and a written guarantee before work begins.
Contact the energy supplier that commissioned the work immediately, they remain liable. Also report the issue to Ofgem and the Energy Ombudsman. Keep all documentation, including photos and contracts.
