Solid Wall Insulation

Thursday 17th July 2025 Written Statements

[The Parliamentary Under-Secretary of State for Energy Security and Net Zero (Miatta Fahnbulleh)]

On 23 January, I informed the House of the discovery of widespread non-compliance with industry standards specifically in relation to the installation of solid wall insulation under the energy company obligation 4 scheme and the great British insulation scheme. At that time, I confirmed that the Government had request Ofgem to oversee an expanded programme of checks, and committed to updating the House once further information on the scale and scope of the issue became available.

Since January, my Department has been working with Ofgem, TrustMark, certification bodies, and others within the oversight regime to understand the scale of these issues. The statistically representative audit programme is due to complete later in the summer, and results will be published in the autumn. However, the preliminary evidence from these audits suggests that a majority of properties that have had solid wall insulation measures under these schemes have not had these installed to the appropriate standard. Some instances of poor-quality work, including inadequate ventilation or roof-line extensions, could, over time, lead to issues like damp and mould. This scale of non-compliance is unacceptable, and consumers will understandably be concerned.

Auditors have experienced some difficulty in obtaining consent to access people’s homes to check the quality of their installation. The Government are 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. I will be writing to Members, asking them to pass on this information.

Our priority remains ensuring that poor installations are identified and remediated as quickly as possible, with no cost to the consumer. Since January, Ofgem has contacted all 60,000 consumers who have had solid wall insulation under both schemes. Thousands of households have already had on-site checks conducted, and where issues have been identified, installers have been asked to remediate these. To date, 90% of the poor-quality installations that were identified in the initial audits conducted by TrustMark have been remediated. However, there is significant work to do to provide remediation for all households that are potentially impacted. We expect all installers to continue to demonstrate their commitment to ensuring households receive timely and high-quality remediation of any non-compliance identified. Where the responsible installer has gone out of business, we encourage consumers to reach out to their guarantee provider.

Should consumers have concerns about the solid wall insulation installed in their property under ECO4 and the Great British insulation scheme, or the process for seeking remediation, they can contact the Ofgem dedicated contact centre for advice and support by email at [e-mail], or by freephone on 0808 169 444, Mondays to Fridays (excluding bank holidays) from 9:30 am to 4:30 pm.

TrustMark and certification bodies will continue to carry out spot checks on other measures and schemes as part of their wider audit activity, although internal and external wall insulation have been prioritised. The current evidence is that compliance levels are higher in other measure types under ECO4 and GBIS.

We have reviewed, at pace, measures undertaken on homes under the local authority delivery, social housing decarbonisation fund and the home upgrade grant schemes. Current data suggests there is not a widespread issue in those schemes, and where non-compliant installations have been identified, the majority of these have been resolved through swift action by the supply chain. We will continue to monitor these schemes as ongoing work continues.

The potential scale of non-compliant solid wall insulation installed under ECO4 and GBIS points to a systemic failure with these schemes. We have taken immediate action to improve the oversight of installations while we bring forward root-and-branch reforms to the wider consumer protection system. Actions to date include:

Energy suppliers carrying out enhanced desk-based and on-site checks, and increased oversight of subcontractors;

Suspension of installers, and a rigorous process for reinstatement, following remediation of all issues in identified properties;

Greater oversight of TrustMark’s operations through a memorandum of understanding, and the appointment of a departmental board observer;

An updated standard, PAS 2035/2030:2023, which came into force on 30 March 2025, has introduced a requirement for retrofit co-ordinators to conduct site visits, and raised the qualification standards for retrofit designers.

Agreement from certification bodies that installers should hold only one PAS 2030 certification per measure type, to improve accountability.

However, we are clear that we will need to go much further. We will be engaging with energy suppliers, certification bodies and installers over the coming weeks to put in place further steps to minimise the risk of further poor-quality installs, and to accelerate the ongoing remediation process, ensuring that installers meet their responsibilities to remediate any non-compliant work.

Finally, it is clear that an overhaul of the retrofit system and the consumer protection landscape is urgently required. This is being brought forward as part of the Government warm homes plan in autumn. Reforms will consider how we certify the competence of installers working to upgrade homes and provide a clear system of oversight, redress and guarantees for when work goes wrong. This will support higher quality installations and greater consumer confidence in retrofit measures.

To ensure we get this right, I am convening an expert panel to advise the Government as we develop and implement these reforms. This panel will have expertise from across consumer groups and the construction sector.

I am committed to delivering a system that is robust, transparent, and delivers high-quality outcomes for consumers. I will continue to keep the House informed as this important work progresses.

[HCWS851]