Published: 14 October 2025 | Sources: BBC News, The Guardian, Financial Times
A new report from the National Audit Office has revealed that 98% of external wall insulation installed under government-funded schemes now requires repair or replacement. For many homeowners, that’s devastating news — with damp, mould, ventilation issues, and even electrical safety risks reported in properties that were meant to become more energy efficient.
The findings point to poor workmanship, a lack of quality control, and weak oversight as key causes. Below, we’ll unpack what went wrong, what it means for UK homeowners, and how to protect your property moving forward.
What Went Wrong?
Government-backed schemes such as ECO and the Great British Insulation Scheme (GBIS) were introduced to help households save energy and cut emissions. However, the drive to meet installation targets led to a “quantity over quality” approach in some cases.
According to the NAO report, thousands of homes were insulated without proper checks or ventilation planning — resulting in issues that are now emerging years later.
Common problems include:
- Damp and mould forming behind insulation due to trapped moisture and poor detailing.
- Blocked ventilation causing condensation and poor indoor air quality.
- Incorrect sealing that allows heat to escape, defeating the purpose of insulation.
- Unsafe practices near electrics and brickwork, creating long-term hazards.
What This Means for Homeowners
If you had insulation fitted through a government or grant-funded scheme, it’s worth getting it checked — particularly if you’ve noticed new patches of damp, mould, or declining heating performance. The insulation product itself isn’t necessarily bad, but installation quality, missing ventilation, and non-compliance with building standards are major factors.
Proper insulation is about balance — maintaining warmth, ventilation, and moisture control together. For lofts, for example, simple upgrades like Felt Lap Vents help air circulate and prevent condensation build-up.
How to Protect Yourself (Checklist)
- ✅ Request proof of accreditation & insurance before work begins.
- ✅ Check reviews and case studies, not just badges and logos.
- ✅ Ensure ventilation and condensation control are included in the plan.
- ✅ Ask for a written guarantee covering both materials and workmanship.
- ✅ Verify compliance with PAS 2030/2035 standards for retrofit work.
- ✅ For lofts, choose modern, survey-friendly insulation that meets RICS and Building Regs standards.
The Carbon Zero Solutions Approach
At Carbon Zero Solutions Ltd, we’ve always said insulation is about creating a healthy, balanced environment — warm in winter, cool in summer, and dry all year round. That’s why we:
- Recommend Felt Lap Vents and Loft Legs on all loft insulation projects.
- Use only certified, trained installers.
- Provide photo evidence and survey-ready documentation for every job.
- Offer honest, no-obligation advice before work begins.
Final Thought
This scandal doesn’t mean insulation doesn’t work — it means it wasn’t done properly. When installed correctly, insulation is one of the smartest and most effective ways to lower energy bills, improve comfort, and boost property value.
If you’re unsure about your insulation or planning an upgrade, speak to us — we’re here to help.
👉 Request your free, no-obligation insulation health check
Further Reading
Official Reports & Coverage:
🔗 BBC News – “Almost all external insulation fitted under government scheme needs repair”
🔗 The Guardian – Environment Section
🔗 Financial Times – Climate Capital
See also: The Complete Guide to Home Insulation in the UK (2025 Edition)
Click the link above to read more.
