NAO Report November 2024:98% failure rate revealed

Government Schemes

Great British Insulation Scheme (GBIS) Problems: What Homeowners Need to Know

The Great British Insulation Scheme launched in 2023 as the government's flagship energy efficiency program. Within months, serious installation failures emerged. This comprehensive guide explains the problems, your rights, and how to get help.

Critical Finding
The November 2024 NAO report found that 98% of homes with GBIS-funded external wall insulation will likely develop damp or mould problems. The scheme shares the same systemic failures as ECO4.

What Is the Great British Insulation Scheme (GBIS)?

The Great British Insulation Scheme (GBIS) was launched in April 2023 as a replacement for the Green Homes Grant scheme. It aims to improve the energy efficiency of homes in Great Britain by installing insulation measures. The scheme runs until March 2026 with a budget of £1 billion.

GBIS Key Facts

Launch Date:April 2023
End Date:March 2026
Total Budget:£1 billion
Target Installations:300,000 homes
Delivery Method:Energy suppliers via contractors

GBIS vs ECO4: What's the Difference?

Many homeowners confuse GBIS with ECO4 (Energy Company Obligation 4). While both are government-backed insulation schemes running simultaneously, they have different eligibility criteria and focus areas.

FeatureGBISECO4
Primary FocusInsulation measures onlyFull retrofit including heating
EligibilityCouncil Tax bands A-D, low EPC ratingsBenefits recipients, low income
Income RequirementsNot means-tested in general routeStrict income/benefit requirements
Available MeasuresCavity wall, loft, room-in-roof insulationAll insulation types + heating systems
External Wall InsulationNot typically coveredAvailable for eligible properties
Inspection Rate4.7% (NAO 2024)4.7% (NAO 2024)
Shared Problems
Despite their differences, GBIS and ECO4 share the same fundamental oversight failures: inadequate inspections, poor contractor vetting, and insufficient quality control. The NAO report criticizes both schemes equally.

The Major Problems with GBIS

1. Catastrophically Low Inspection Rates

The National Audit Office's November 2024 report revealed that only 4.7% of GBIS installations receive any form of inspection. This means 95.3% of work is never checked for compliance, quality, or safety.

Installations Inspected4.7%
Installations Never Checked95.3%

2. Unsuitable Insulation Types for Property Characteristics

GBIS prioritizes "easy wins" - cavity wall and loft insulation - regardless of whether properties are suitable. The scheme's volume-based targets incentivize quick installations over proper assessments.

Properties at Risk

  • Pre-1920s properties with solid walls
  • Homes with existing damp issues
  • Properties with poor ventilation
  • Coastal or exposed locations
  • Listed or conservation area buildings

What Should Happen

  • Comprehensive property survey before work
  • Moisture and ventilation assessment
  • Building fabric compatibility check
  • Written explanation if insulation unsuitable
  • Alternative measures recommended

3. Contractor Quality and Oversight Issues

GBIS relies on the same broken Trustmark certification system as ECO4. Contractors can self-certify work, and the "phoenix company" pattern allows failed installers to simply close and re-open under new names.

The Phoenix Company Problem
Between 2020-2024, over 200 Trustmark-certified insulation contractors closed their businesses after complaints, only to re-register under different company names with the same directors. GBIS has no effective mechanism to prevent this.

4. Inadequate Consumer Protection

Unlike traditional building work, GBIS installations often bypass normal consumer protections. Homeowners report being pressured to sign contracts quickly, receiving incomplete documentation, and struggling to get warranties honored.

Common Consumer Protection Failures

1
No Cooling-Off Period

Work often starts immediately without the standard 14-day cooling-off period required for doorstep sales.

2
Unclear Warranty Terms

Insurance-backed guarantees are promised but documentation is incomplete or never provided.

3
Liability Gaps

When contractors fold, homeowners discover the warranty provider denies claims due to technical exclusions.

4
No Independent Advocacy

Complaint processes require homeowners to navigate complex bureaucracy alone against well-resourced companies.

Real-World GBIS Failure Examples

Cavity Wall Insulation Causing Penetrating Damp

GBIS-funded cavity wall insulation is particularly problematic in properties with cavity widths below 50mm, partial-fill cavities, or exposure to driving rain. The scheme's assessment process rarely identifies these risk factors.

Typical Timeline of Failure:

Month 0: GBIS cavity wall insulation installed in 1 day

Month 3-6: First signs of damp patches on internal walls

Month 12: Visible mould growth, musty smell, wallpaper peeling

Month 18+: Structural damage to plaster, timber frame deterioration

Loft Insulation Causing Condensation

Over-insulation without adequate ventilation is a common GBIS issue. Contractors install the maximum depth of loft insulation (270mm+) without checking or upgrading roof ventilation, leading to condensation in roof spaces.

What to Do If Your GBIS Installation Has Failed

Step 1: Document Everything Immediately

  • Take photos/videos of all damp, mould, or damage with timestamps
  • Find all paperwork: contracts, certificates, warranties, assessment reports
  • Keep a diary noting when problems appeared and how they've worsened
  • Track costs: dehumidifiers, decorating, heating bills, health impacts

Step 2: Contact the Installer in Writing

Send a formal written complaint to the contractor who did the work. Use recorded delivery and keep copies. Give them 14 days to respond with a plan to rectify the problems.

Step 3: Report to Trustmark and the Energy Supplier

File complaints with both Trustmark (the certification scheme) and the energy supplier who funded the work through GBIS. Both have obligations to investigate and resolve issues.

Step 4: Get an Independent Survey

Hire a qualified building surveyor or damp specialist (not connected to the scheme) to assess the problems and confirm causation. This report is crucial for any compensation claim.

Survey Costs
Professional surveys typically cost £300-£600 but are essential evidence for claims. Some homeowners insurance policies cover survey costs for building defects.

Step 5: Consider Legal Action

If the contractor, Trustmark, or energy supplier won't resolve the issue, you may need legal representation. Many solicitors offer no-win-no-fee arrangements for insulation failure cases.

Your Legal Rights Under GBIS

Despite being "free" government schemes, you have the same consumer rights as paying customers:

Consumer Rights Act 2015

Work must be performed with reasonable care and skill. Materials must be of satisfactory quality. You can claim for poor workmanship.

Building Regulations 2010

All insulation work must comply with Part C (Site preparation and resistance to contaminants and moisture) and Part L (Conservation of fuel and power).

Misrepresentation Act 1967

If contractors made false claims about suitability or benefits, you may have grounds to rescind the contract and claim damages.

GBIS Compensation: What You Can Claim

Successful GBIS compensation claims typically include:

Direct Costs

  • Insulation removal£2,000-£5,000
  • Damp remediation£1,500-£8,000
  • Replastering/repairs£3,000-£12,000
  • Redecoration£1,000-£4,000
  • Survey/expert fees£500-£1,500

Indirect Costs

  • Increased heating bills£400-£1,200/year
  • Dehumidifier costs£200-£600/year
  • Temporary accommodation£2,000-£10,000
  • Property value loss£10,000-£50,000
  • Distress/inconvenience£1,000-£5,000

How to Avoid GBIS Problems

If You're Considering GBIS

Essential Checks Before Accepting GBIS Work

  1. 1.Demand a full building survey - not just a quick visual assessment. This should check cavity width, wall construction, moisture levels, and ventilation.
  2. 2.Get a written guarantee that the insulation type is suitable for your specific property type and location.
  3. 3.Verify contractor credentials independently - check Companies House, reviews, and how long they've been trading.
  4. 4.Obtain full warranty documentation before work starts, including the insurance-backed guarantee certificate.
  5. 5.Request references from recent local installations and follow up to check for any emerging problems.
  6. 6.Never accept same-day installations - insist on a minimum 14-day cooling-off period to review all documentation.

Red Flags to Watch For

Pressure Tactics
Limited time offers, 'special deals,' or claims that you must decide today.
Vague Assessments
Quick visual check without measuring equipment or detailed inspection.
Missing Paperwork
No written contract, incomplete warranties, or 'we'll send it later' promises.
Cash Incentives
Offers of cash back, Amazon vouchers, or other inducements to sign immediately.
Generic Recommendations
Same insulation type recommended regardless of property characteristics.
New Companies
Contractor trading for less than 2 years or recently changed company name.

The Future of GBIS

Following the NAO's damning November 2024 report, the government faces pressure to either fundamentally reform or suspend GBIS. Key recommendations include:

  • Increasing inspection rates from 4.7% to at least 20%
  • Mandatory independent pre-installation surveys
  • Ending contractor self-certification
  • Creating a compensation fund for failed installations
  • Proper enforcement against repeat-offending contractors
  • Stronger consumer protections and clearer warranties

However, as of November 2024, GBIS continues to operate under the same flawed framework. Homeowners considering scheme-funded insulation should proceed with extreme caution.

Get Expert Help with GBIS Problems

If you're experiencing issues with GBIS-funded insulation, we can connect you with specialists who understand these specific schemes and can help you navigate the complaint and compensation process.

Get Free Assessment

Frequently Asked Questions

Is GBIS the same as the Green Homes Grant?

No. The Green Homes Grant ended in 2021. GBIS replaced it in April 2023 with a different structure but similar aims. GBIS runs until March 2026.

Can I refuse GBIS work if I'm eligible?

Yes, absolutely. Eligibility doesn't mean you must accept the work. If you have concerns about suitability, you should decline and seek independent advice.

Who pays for GBIS remediation if it fails?

Legally, the contractor is liable for defective work. However, many have folded. You may need to claim against Trustmark, the warranty provider, or the energy supplier. We can help you identify the responsible parties.

How long do GBIS warranties last?

Standard GBIS installation warranties are 2 years for workmanship and 25 years for insurance-backed guarantees. However, warranty providers often dispute claims based on technical exclusions.