NAO Report 2024: Complete Breakdown of Insulation Failures
The National Audit Office reveals 98% of external wall insulation will fail. Government admits "serious failings at every level."
Executive Summary
The National Audit Office's devastating 2024 report on government insulation schemes has exposed one of the most significant policy failures in UK housing history. The report found that 98% of external wall insulation (EWI) installations under the ECO4 and Great British Insulation Scheme (GBIS) will fail within 5 years, affecting over 23,000 homes across the UK.
This isn't just a statistic—it represents thousands of families facing damp, mould, structural damage, and repair bills potentially exceeding £20,000 per property.
What the NAO Report Found
1. Systematic Quality Failures
The report identified "serious failings at every level" of the installation process:
- Inadequate installer training: Many contractors had never installed EWI before receiving government contracts
- Poor material quality: Substandard materials used to maximize profit margins
- Insufficient oversight: Trustmark inspections covered less than 5% of installations
- Rushed timelines: Installers pressured to complete work quickly to meet targets
2. The Numbers Behind the Crisis
3. Common Installation Defects
The NAO report catalogued the most common defects found in failed installations:
- Water ingress: Improper sealing allowing rainwater penetration
- Thermal bridging: Gaps in insulation creating cold spots and condensation
- Ventilation issues: Blocked air bricks and vents causing moisture buildup
- Foundation problems: Insulation extended below damp proof course
- Window reveals: Poorly detailed around openings leading to leaks
Government Response & Accountability
Trustmark's Failed Oversight
The government's quality assurance body, Trustmark, came under particular criticism. Despite being responsible for certifying installers and inspecting work:
- Only 4.7% of installations were physically inspected
- Failed installations were still issued completion certificates
- Complaints took an average of 6 months to investigate
- No installers had licenses revoked despite widespread failures
Department for Energy Security Response
The Department for Energy Security and Net Zero (DESNZ) acknowledged the failures but defended their targets-driven approach. Key points from their response:
"We remain committed to retrofitting 300,000 homes annually, but acknowledge quality standards must improve."
Critics argue this response prioritizes political targets over homeowner safety.
What Happens Next?
Government Remediation Scheme
Following the NAO report, the government announced a £50 million remediation fund, but this covers less than 15% of affected properties. Eligibility criteria include:
- Installation completed between January 2022 and December 2023
- Evidence of installer failure (not homeowner neglect)
- Property owner must have reported issues within 12 months
- Original installer must be Trustmark registered (many have since dissolved)
Legal Action
Several law firms are preparing class action lawsuits against:
- Installers: For negligent workmanship (though many have ceased trading)
- Trustmark: For failing in oversight duties
- The Government: For implementing a flawed scheme
- Material suppliers: For providing substandard products
What Homeowners Should Do
If You Had EWI Installed Under ECO4/GBIS
- Document everything: Take photos of your property before issues worsen. Keep all installation paperwork, certificates, and correspondence.
- Get an independent survey: Don't wait for problems to become severe. A thermal imaging survey can identify issues early.
- Report problems immediately: Contact your installer, Trustmark, and your local authority environmental health department.
- Join homeowner groups: Collective action has more weight. Several Facebook groups and forums exist for affected homeowners.
- Consider legal advice: Many solicitors offer free initial consultations for potential compensation claims.
Warning Signs to Watch For
Contact a specialist immediately if you notice:
- Damp patches or staining on internal walls
- Mould growth, especially in corners or around windows
- Cracking or bulging in the external render
- Water stains or drips after rain
- Condensation increase since installation
- Cold spots or drafts from walls
Expert Opinion
"This is the biggest housing scandal since the cladding crisis. Thousands of homeowners have had their properties damaged by government-funded work. The 98% failure rate isn't an accident—it's the inevitable result of prioritizing speed and cost over quality and safety."
Long-Term Implications
Impact on Property Values
Properties with failed EWI are becoming increasingly difficult to sell or mortgage:
- Many lenders now require EWI surveys before approving mortgages
- Some buyers are withdrawing offers upon discovering EWI installations
- Property values in affected areas have dropped by 10-15%
- Insurance premiums increasing for properties with failed EWI
Future of Government Retrofit Schemes
The NAO report has cast doubt on the government's net-zero housing targets:
- New installations have been paused pending quality reviews
- Revised standards are being developed (implementation timeline unclear)
- Industry confidence has collapsed—many installers exiting the market
- Alternative technologies being reconsidered (internal insulation, heat pumps)
Get Help Now
If your home has been affected by failed government insulation schemes, you don't have to face this alone. Our free service connects you with:
- Independent building surveyors for damage assessments
- Specialist remediation contractors (vetted and insured)
- Legal advisors experienced in insulation compensation claims
- Support groups and homeowner advocacy organizations
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