UK Inquiry Tracker

Faulty energy efficiency installations

Public Accounts Committee Open Inquiry

Opened: 10 Jul 2025 Parliament page

The Energy Company Obligation 4 (ECO4) and the Great British Insulation Scheme (GBIS), both funded via energy consumers’ bills, are government schemes for the installation of energy-efficiency improvements in people’s homes, such as insulation. Not-for-profit quality assurance company TrustMark identified issues with both schemes, with government announcing in January 2025 … Read more The Energy Company Obligation 4 (ECO4) and the Great British Insulation Scheme (GBIS), both funded via energy consumers’ bills, are government schemes for the installation of energy-efficiency improvements in people’s homes, such as insulation. Not-for-profit quality assurance company TrustMark identified issues with both schemes, with government announcing in January 2025 issues including insufficient ventilation, missing or exposed insulation leading to damp and mould. The PAC has found issues on a number of occasions with similar retrofit schemes. Its 2018 report on the Renewable Heat Incentive found that it failed to meet its objectives or provide value for money against a £23bn total cost to taxpayers, while its 2021 report on Green Homes Grants found the scheme’s design was overly complex and that government had persistently failed to learn lessons from previous energy efficiency schemes. In 2025, the National Audit Office publishes its investigation into energy efficiency installations. Proceeding from the NAO investigation’s findings, the PAC will hear from senior officials at the Department for Energy Security and Net Zero the regulator Ofgem, and others, on subjects including what efforts government has taken to remediate problems, how much this will cost the public purse, and the impact on achieving carbon net zero by 2050. If you have evidence on these issues, please submit here by 23:59 on Thursday 30 October 2025. Please look at the requirements for written evidence submissions and note that the Committee cannot accept material as evidence that is published elsewhere. You can request anonymity or confidentiality when you send evidence, but it is the Committee which decides what information to publish and how. It may treat submissions confidentially, even where you have not requested this. Please note that the Committee’s inquiry cannot assist with individual cases. If you need help with an individual problem you are having, you may wish to read the information on Parliament’s website about who you can contact with different issues . The Energy Company Obligation 4 (ECO4) and the Great British Insulation Scheme (GBIS), both funded via energy consumers’ bills, are government schemes for the installation of energy-efficiency improvements in people’s homes, such as insulation. Not-for-profit quality assurance company TrustMark identified issues with both schemes, with government announcing in January 2025 issues including insufficient ventilation, missing or exposed insulation leading to damp and mould. The PAC has found issues on a number of occasions with similar retrofit schemes. Its 2018 report on the Renewable Heat Incentive found that it failed to meet its objectives or provide value for money against a £23bn total cost to taxpayers, while its 2021 report on Green Homes Grants found the scheme’s design was overly complex and that government had persistently failed to learn lessons from previous energy efficiency schemes. In 2025, the National Audit Office publishes its investigation into energy efficiency installations. Proceeding from the NAO investigation’s findings, the PAC will hear from senior officials at the Department for Energy Security and Net Zero the regulator Ofgem, and others, on subjects including what efforts government has taken to remediate problems, how much this will cost the public purse, and the impact on achieving carbon net zero by 2050. If you have evidence on these issues, please submit via the Call for Evidence portal. The deadline for written evidence will be announced in due course. Please look at the requirements for written evidence submissions and note that the Committee cannot accept material as evidence that is published elsewhere. You can request anonymity or confidentiality when you send evidence, but it is the Committee which decides what information to publish and how. It may treat submissions confidentially, even where you have not requested this. Please note that the Committee’s inquiry cannot assist with individual cases. If you need help with an individual problem you are having, you may wish to read the information on Parliament’s website about who you can contact with different issues . Show less

19 Recommendations

20 Conclusions

1 Report

1 Oral session

6 Letters

1 Event

Activity timeline 10 events

21 May
2026

Correspondence

Letter to the Permanent Secretary at the Department for Energy Security and Net Zero relating to Faulty energy efficiency installations, 21…

7 Apr
2026

Report published

Treasury minutes: Government response to the Committee of Public Accounts on the Sixty-second report from Session 2024-26

23 Feb
2026

Correspondence

Letter from the Interim Permanent Secretary at the Department for Energy Security and Net Zero relating to Recommendation 3 of the Committe…

23 Jan
2026

Report published

62nd Report - Faulty energy efficiency installations

12 Jan
2026

Correspondence

Letter from the Chief Executive Officer of the Installation Assurance Authority Federation relating to the Committee’s evidence session on …

8 Dec
2025

Correspondence

Letter from the Chief Executive of the UK Accreditation Service relating to the Committee’s evidence session on Faulty energy efficiency in…

8 Dec
2025

Correspondence

Letter from the Interim Permanent Secretary at the Department for Energy Security and Net Zero relating to the Committee’s evidence session…

1 Dec
2025

Correspondence

Letter from the Chief Operating Officer at TrustMark relating to the Committee’s evidence session on Faulty energy efficiency installations…

13 Nov
2025

Oral evidence

Oral evidence session

13 Nov
2025

Formal meeting (oral evidence session) · The Grimond Room, Portcullis House

Committee event

Oral evidence sessions 1 session

13 Nov 2025

View on parliament.uk

Clive Maxwell CB CBE · Department for Energy Security and Net Zero Deborah Chittenden · Department for Energy Security and Net Zero Jeremy Pocklington CB · Ministry of Defence Jonathan Brearley · Department for Energy Security and Net Zero Jonathan Brearley · Ofgem Kiera Schoenemann · Ofgem Matt Gantley · United Kingdom Accreditation Service (UKAS) Simon Ayers MBE · TrustMark

Reports 1 report · click to expand

Title	HC No.	Published	Items	Response
62nd Report - Faulty energy efficiency installations	HC 1229	23 Jan 2026	39	Responded

Recommendations & Conclusions

12 results

13 Conclusion Not Addressed

62nd Report - Faulty energy effici…

Installer suspension and reinstatement process insufficient for widespread insulation failures

To limit further faulty installations, the Department asked the certification bodies and scheme providers, via TrustMark, to suspend installer businesses based on their failure rate. By the end of January 2025, 38 installers had been suspended, preventing them from carrying … Read more

Government Response

The response addresses a different recommendation regarding a blanket ban on external/internal wall insulation installations, not the specific issues raised in this conclusion about the suspension and reinstatement of installers.

HM Treasury

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15 Conclusion Not Addressed

62nd Report - Faulty energy effici…

Delays in fixing faulty installations increase property damage and health risks

Delays in finding and fixing these homes increase the risk of damage to the property, including damp and mould, and leave people in homes with unaddressed health and safety risks.29 We asked the witnesses how they would make sure the … Read more

Government Response

HM Treasury

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16 Conclusion Not Addressed

62nd Report - Faulty energy effici…

Provide regular six-monthly updates to the Committee on external wall insulation remediation progress.

The Department and TrustMark told us that TrustMark would oversee a find-and-fix process for homes with external wall insulation. It would offer audits to all homes with external wall insulation installed through ECO4 or GBIS, provide direct oversight to ensure … Read more

Government Response

HM Treasury

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17 Conclusion Not Addressed

62nd Report - Faulty energy effici…

Current plans for identifying faulty internal wall insulation lack proactive detection of hidden defects.

The Department told us that it plans to identify faulty internal wall insulation through existing audit processes. First, TrustMark and the certification bodies continue to conduct business-as-usual audits. Second, households with concerns can contact their installer and certification body, or … Read more

Government Response

HM Treasury

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18 Conclusion Not Addressed

62nd Report - Faulty energy effici…

We asked the witnesses why no-one warned the Department about the risks or flaws with the system it had designed, or considered whether the system as a whole was protecting consumers.72 While TrustMark accepted it should have done much more, … Read more

Government Response

The response addresses a different recommendation, regarding an annual report on retrofit schemes, and not the conclusion about lack of warnings about the risks or flaws of the system.

HM Treasury

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Government Response AI assessment · 37 of 19 classified

Accepted 9

Accepted in Part 2

Acknowledged 1

Deferred 3

Not Addressed 12

Rejected 10

Total 19 recs + 20 conclusions

Correspondence 6 letters

21 May 2026 From committee Letter to the Permanent Secretary at the Department for Energy Security and Net Zero relating to Faulty energy efficiency installations, 21 May 2026

Parliament page

23 Feb 2026 To committee Letter from the Interim Permanent Secretary at the Department for Energy Security and Net Zero relating to Recommendation 3 of the Committee’s Report on Faulty energy efficiency installations, 06 February 2026

Parliament page

12 Jan 2026 To committee Letter from the Chief Executive Officer of the Installation Assurance Authority Federation relating to the Committee’s evidence session on 13 November 2025 on Faulty energy efficiency installations, 23 December 2025

Parliament page

8 Dec 2025 To committee Letter from the Chief Executive of the UK Accreditation Service relating to the Committee’s evidence session on Faulty energy efficiency installations on 13 November 2025, 27 November 2025

Parliament page

8 Dec 2025 To committee Letter from the Interim Permanent Secretary at the Department for Energy Security and Net Zero relating to the Committee’s evidence session on Faulty energy efficiency installations on 13 November 2025, 02 December 2025

Parliament page

1 Dec 2025 To committee Letter from the Chief Operating Officer at TrustMark relating to the Committee’s evidence session on Faulty energy efficiency installations on 13 November 2025, 25 November 2025

Parliament page