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

9 results

3 Recommendation Accepted

62nd Report - Faulty energy effici…

Update how to protect households from unaffordable repair bills when guarantees are insufficient.

Households do not have real assurance the government will protect them from unaffordable bills when the original installer or guarantees do not cover the cost of repairs. Ministers have stated that no household should have to pay to fix the … Read more Households do not have real assurance the government will protect them from unaffordable bills when the original installer or guarantees do not cover the cost of repairs. Ministers have stated that no household should have to pay to fix the issues. The original installer is liable for fixing the installation and costs up to £20,000 should be covered by a guarantee when the installer has ceased to trade or fails to remediate. This process leaves some households unprotected. Remediation costs will sometimes exceed the guarantee cap. It should normally cost between £250 and £18,000 per home to correct the installation, but in the worst case we are aware of it cost over £250,000 to fix the defects and resultant damage. We are sceptical that the original installers and the guarantee providers will be able to withstand the potential scale of claims. Households have not yet claimed on guarantees in large numbers, but not all installers are complying with the remediation process, and some company directors are closing and restarting their businesses to avoid remediation responsibilities. The Department plans to bring ECO partners together to find bespoke solutions for the “very small number” of households it anticipates will not be sufficiently covered under standard processes. We find neither the Department’s proposed solution nor its downplaying of the likely scale 4 of the problem at all credible. Since we took evidence in November 2025, the government has announced that it will end ECO. There will be no additional obligation beyond the existing ECO4 and GBIS targets and no levy on bills from April 2026, although the Department is yet to confirm whether it will extend the period for suppliers to meet their existing ECO4 obligations beyond March 2026. We are concerned there may not be a big enough retrofit market once ECO ends to ensure enough installers remain viable businesses able to complete the remediation. recommendation Given the urgency of this matter, the Departm Show less

Government Response

The government accepted the recommendation, stating that it provided responses to the Committee's three requests via a letter on 6 February 2026.

HM Treasury

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4 Recommendation Accepted

62nd Report - Faulty energy effici…

Review risk management and internal escalation systems to swiftly address scheme issues.

The Department’s senior officials took two years to recognise the scale of the problems, which led to many faulty installations that could have been avoided. This is unacceptable and demonstrates very poor overall supervision. The Department acted in October 2024 … Read more The Department’s senior officials took two years to recognise the scale of the problems, which led to many faulty installations that could have been avoided. This is unacceptable and demonstrates very poor overall supervision. The Department acted in October 2024 when TrustMark informed it of analysis indicating high levels of non-compliance with quality standards in external wall insulation. TrustMark only developed the analytical capabilities for interrogating its data and producing this kind of analysis in the latter half of 2024–prior to this it did not have the resources or systems to oversee what was happening on the ground. The Department should have done the due diligence on this before Trustmark were appointed to this role, however, the Department had access to other information that should have alerted it to the potential issues much earlier given that the ECO4 scheme started in April 2022. For example, TrustMark told us it had been sharing the results of its audits with the Department from 2022 and that when it started to identify the increased risk from 2023 into 2024, it undertook more audits to better 5 understand the level of risk. The Department’s failure to take minutes of its meetings with TrustMark meant it was unable to defend its position that it had not been alerted sooner. The Department also had risks to quality, assessments and standards on its programme risk register since November 2022 but did not take any proactive steps to prevent the risks materialising in the first place or escalate the risks appropriately. The Department gave the scheme virtually no senior level attention and should have carried out far more investigations much sooner. Its poor oversight of ECO4 and GBIS meant that senior leaders had assumed the quality assurance system was working when it was not. recommendation The Department should review its risk management and internal escalation systems so that issues identified within specific schemes are escalated swiftly and Show less

Government Response

The government accepted the recommendation, stating that risk management and escalation within DESNZ are managed through formal governance. In response to issues, they have established an internal programme board, an external expert panel, and a project board for the find-and-fix programme, with a senior civil servant now observing on the TrustMark board.

HM Treasury

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5 Recommendation Accepted

62nd Report - Faulty energy effici…

Publish an annual report to Parliament on all retrofit schemes, non-compliance and fraud.

The Department’s system of quality assurance and consumer protection was far too complicated, and organisations within it focused too much on their own tasks rather than whether the system was protecting consumers. The ECO schemes and the retrofit quality assurance … Read more

Government Response

The government accepted the recommendation, committing to publishing an annual report to Parliament on retrofit schemes, non-compliance, and estimated fraud before Autumn 2027, to be included in the department’s Annual Report and Accounts. It will also establish a standard methodology for reporting on error and fraud for new and existing schemes.

HM Treasury

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7 Recommendation Accepted

62nd Report - Faulty energy effici…

Prioritise robust customer protection and remediation for all government-funded retrofit schemes

The serious failings to protect consumers on these schemes risk undermining confidence in all the Department’s retrofit schemes. The Department believes it is rebuilding confidence through the steps it has taken to date, such as suspending 38 installer businesses, implementing … Read more The serious failings to protect consumers on these schemes risk undermining confidence in all the Department’s retrofit schemes. The Department believes it is rebuilding confidence through the steps it has taken to date, such as suspending 38 installer businesses, implementing a “robust” reinstatement process, and requiring retrofit coordinators to visit 7 each site in person. We are extremely sceptical that the changes so far are sufficient, especially given the low level of remediation that has taken place to date. For example, there is still no requirement for the retrofit coordinator to be independent of the installer, so the person who is meant to check the retrofit has been completed to the correct standard can be appointed by the installer they are assessing. The Department needs to make further changes before it can be confident there will be no more faulty installations under the current system. Since we took evidence in November 2025, the government announced that it would not continue ECO after the current schemes end, but that it would continue to invest in tackling fuel poverty through its Warm Homes Plan. It is vital, given the Departments strong statement that in the last resort it will stand by householders to ensure their homes are remediated that high priority is given to this pledge even after the scheme ends. The Department accepts that wholesale reform of the system is ultimately required to ensure customer protection and restore the public’s confidence in retrofits. It intends to deliver this reform in line with three principles: the system must be simpler and clearer; there must be stronger central oversight; and there must be clear accountability, redress and remediation when things go wrong. The public have a right to expect that where work is funded by government grant that the government effectively guarantee the work will be done correctly and put right if not. recommendation a. The Department should give high priority to ensuring—and ind Show less

Government Response

The government accepted the recommendation, affirming high priority for the find-and-fix programme and committing to wholesale reform of the consumer protection system as outlined in the Warm Homes Plan, including developing new competency frameworks.

HM Treasury

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25 Recommendation Accepted

62nd Report - Faulty energy effici…

Ensure Government steps in to remediate defects when other avenues are exhausted.

The Department told us that the Ministers are very clear these problems must be fixed at no cost to households who have done nothing wrong. It told us it expects only a “very small number” of homes to not be … Read more

Government Response

The government agrees with the recommendation to step in and ensure defects are remediated where all other avenues have been exhausted, even though the scheme has closed.

HM Treasury

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27 Recommendation Accepted

62nd Report - Faulty energy effici…

Department provided limited oversight and influence over ECO4 and GBIS schemes.

The National Audit Office reported that the Department designed both ECO and the consumer protection and quality assurance system to operate at arm’s length from government, and that the Department gave itself limited oversight and influence of ECO4 and GBIS. … Read more

Government Response

The government will publish an annual report to Parliament on its retrofit schemes, their level of non-compliance and estimated fraud, and whether the schemes are working as intended, starting before Autumn 2027. This will be included in the department's Annual Report and Accounts.

HM Treasury

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28 Conclusion Accepted

62nd Report - Faulty energy effici…

Available intelligence on risks and non-compliance was not escalated or consolidated effectively.

The National Audit Office reported that TrustMark only developed the analytical capabilities for identifying non-compliance trends in the latter half of 2024. Its funding model meant it did not have the free cashflow to develop these capabilities sooner.60 However, TrustMark … Read more

Government Response

The government agreed with the Committee’s recommendation. TrustMark reached full operational delivery of the find-and-fix programme in late January 2026 and currently intend for the programme to complete by May 2027 in line with ECO4 closure timeframes.

HM Treasury

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29 Recommendation Accepted

62nd Report - Faulty energy effici…

Department failed to act sufficiently on identified quality risks in its programme register.

Since November 2022, the Department’s programme risk register had included risks to quality, assessments and standards, yet the Department did not take sufficient action to check whether the risks were materialising, to prevent them from happening, or to escalate the … Read more

Government Response

The government states that risk management and escalation is already managed through formal governance across projects, schemes and portfolios, with risks escalated as appropriate. The department is committed to reform of our consumer protection system and has set up both an internal programme board to track progress which includes Treasury and NISTA representation, as well as an external expert panel.

HM Treasury

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30 Recommendation Accepted

62nd Report - Faulty energy effici…

Consumer protection and quality assurance system for ECO4 and GBIS is overly complex.

The National Audit Office’s report considered by the Committee concluded that ECO4 and GBIS combined with the consumer protection and quality assurance system resulted in an overly complex system, with many different actors. It reported that nobody spoken to during … Read more

Government Response

The Department will publish an annual report to Parliament on retrofit schemes, with the first publication before Autumn 2027. This will be included in the department’s Annual Report and Accounts.

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