Thousands of homes at risk of damp and mould over botched insulation, government confirms

Independent

22-07-2025

Tens of thousands of homes fitted with wall insulation installed under a popular scheme could cause owners serious health issues as the government warns of 'systemic' installation failures.
Solid wall insulation was made available under two government-backed schemes over the past few years, allowing homeowners to make their homes more energy efficient for free.
However, 'a majority' of the insulation granted under these schemes was not 'installed to the appropriate standard,' said Labour minister Miatta Fahnbulleh, adding that over time it could lead to damp and mould.
In a statement to Commons, the minister for energy consumers added: 'The government is keen to encourage everyone who is contacted for the purposes of scheduling an audit to strongly consider taking part in these checks, even if they do not think there is anything wrong with their installation.
'Our priority remains to ensure that poor installations are identified and remediated as quickly as possible, with no cost to the consumer.'
Crucially, anyone who is affected by the issue will not have to pay to fix the problem. Installers are required to foot the bill for the issue, and prove they have carried out the work properly with Trustmark, the independent body that oversees tradespeople working in homes.
For anyone whose installer has stopped trading, a guarantee should cover the cost of removal up to £20,000.
The botched insulations were installed under two initiatives: the ' Energy Company Obligation 4 (ECO4)' and 'Great British Insulation Scheme (GBIS)'. They were launched by the government in April 2022 and May 2023, respectively.
These schemes enabled eligible households to apply for free energy-efficiency upgrades through their energy supplier or local council – including solid wall insulation.
Solid walls are most common in properties built before the 1920s. They have no gaps or cavities, and insulating them involves adding material to the inside or outside of them to trap heat.
But a report published by Trustmark in January pointed to 'significant examples' of installations that fell short of the required standards.
Since the findings were revealed, Ofgem has written to the 60,000 households understood to have had insulation fitted under the two schemes.
Ms Fahnbulleh has confirmed that 'thousands of households have already had on site checks conducted,' adding that '90 per cent of the poor-quality installations that were identified in the initial audits conducted by Trustmark have been remediated."
Anyone with concerns about their insulation or with more questions can contact Ofgem