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

2 results

2 Recommendation Accepted in Part

62nd Report - Faulty energy effici…

Set out plans to scale-up the find-and-fix programme for faulty home insulation.

Nearly one year after the problems emerged, around 3,000 homes with defects had been found and fixed out of the more than 30,000 homes estimate to be affected. TrustMark, the government-endorsed quality scheme, did not notify the Department of high … Read more Nearly one year after the problems emerged, around 3,000 homes with defects had been found and fixed out of the more than 30,000 homes estimate to be affected. TrustMark, the government-endorsed quality scheme, did not notify the Department of high levels of faulty installations of external wall insulation until October 2024, more than two years after the start of ECO4 in April 2022. It highlighted similar concerns with internal wall insulation in November 2024. By mid-September 2025, nearly one year later, less than 10% of the estimated total number of affected homes had been found and fixed.1 TrustMark will oversee the programme to find and fix the remaining homes with faulty external 1 This is based on the midpoint of the estimated range of 32,000 to 35,000. 2,934 remediated homes / 33,500 = 9%. 3 wall insulation, of which it estimates there are around 20,000 as of November 2025. It expects to have audited all relevant homes (providing access is granted) within 15 months of when we took evidence in November 2025. TrustMark and the retrofit sector face a serious challenge in scaling-up audit activities at the pace necessary to meet these timescales. The Department plans to identify faulty internal wall insulation through existing audit processes, but we fear it may be overconfident in expecting this approach to be adequate. It is vital that the remaining homes with defects are found and fixed as soon as possible. As waiting times increase, the likelihood of damage occurring increases, and there are immediate health and safety risks that need urgent attention. recommendation a. In its Treasury Minute response, the Department should set out how it plans to scale-up its find-and-fix programme to meet the 15-month ambition and how it will find all the faulty internal wall insulation. b. Given the severity of the issue for residents of affected homes, the Department should be seeking to deliver the find-and-fix programme within a much shorter timeframe and should updat Show less

Government Response

The government accepted the recommendation in part, confirming the find-and-fix programme reached full operational delivery in January 2026, aiming for completion by May 2027, and detailing how faulty internal wall insulation cases will be addressed. However, it stated that delivering the programme on a significantly shorter timescale is unlikely due to constraints, though opportunities will be sought to reduce it.

HM Treasury

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1 Conclusion Accepted in Part

62nd Report - Faulty energy effici…

Widespread major issues found in ECO4 and GBIS insulation installations

On the basis of a deeply concerning report by the Comptroller and Auditor General, we took evidence from the Department for Energy Security and Net Zero (the Department) and Ofgem to find out why an estimated 98% of external wall … Read more

Government Response

The government disagreed with the committee's conclusion that failings undermine confidence in all retrofit schemes, stating it has greater confidence in local authority-delivered programmes. However, it accepted the severity of issues within ECO4 and GBIS, detailing multiple actions taken including offering audits, strengthening the consumer protection system, and implementing new oversight and enforcement measures.

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