The UK’s retrofit ambitions risk collapse under the weight of misplaced priorities. Current policy focuses heavily on installation targets, yet the reality on the ground tells a very different story.

The latest round of retrofit roulette involved the National Audit Office (NAO), which uncovered a staggering 98% failure rate in homes insulated under the ECO scheme, with major defects causing issues such as damp and mould. This colossal failure has led to wasted public and taxpayer money, leaving substandard housing that compromises energy performance and increases health risks for residents.

Far more than a mere technical glitch, this represents a costly misuse of public funds and a profound breach of trust.

Blind retrofitting is failing everyone

At the heart of the problem is a fundamental oversight: much of the UK’s retrofit work is being carried out without the essential steps of assessment and measurement.

Where we’re skipping to intervention without a thorough understanding of the existing building fabric, we’re effectively conducting retrofit blind. This is akin to baking a cake with the right ingredients but no measurements: the outcome will never be consistent or reliable.

Yet, this is our retrofit reality, with consequences far more critical than an undercooked dessert.

It is fundamental that we pivot away from "how many installations were done" to a disciplined focus on "how well they actually perform." If we’re asking consumers to decarbonise, but decisions lack scientific grounding, they’re not being made properly, and trust cannot be expected. With so much at stake, we should be measuring building performance with the same rigor as any other audit. If that approach were applied, we would not need a National Audit Office report to tell us what went wrong.

This is not about pointing fingers; it’s about getting it right. First time. That means embedding measurement as the cornerstone of retrofit, not as an afterthought. Only then can we a shift away from installing to meet political targets and, instead, towards upgrading homes that genuinely deliver on their promises.

Evidence begins with measurement

Effective retrofit isn’t about chasing the latest technology; it’s about taking a fabric-first, evidence-based approach. Without investigation and evidence, intent cannot meet reality. We may know that there’s a performance gap, but without quantifying its scale on a project by project basis, we cannot diagnose the issue or implement effective measures.

This means that a thorough investigation, supported by rapid and reliable measurement techniques, must precede any intervention and be repeated on completion of retrofit works. Only through timely, evidence-based insight can we build a clear picture of performance, guiding investment that avoids waste, disruption, and the continued erosion of trust. Performance is achieved when intent is delivered and demonstrated by trusted results.

Repairing trust and safeguarding public investment

The fallout from failed retrofit isn’t abstract, it’s a direct blow to taxpayers’ pockets and homeowner confidence. At a time of cost-of-living pressures, money wasted on subpar retrofit will have to be spent again, compounding public burden. Furthermore, when promised savings don’t materialise, consumer trust evaporates, jeopardising future decarbonisation initiatives.

Rebuilding this dwindling trust demands transparency, accountability, and a clear shift towards verified performance outcomes. We must assertively reject box-ticking or volume metrics and, instead, prioritise a more rigorous evidence-based approach.

A call for urgent, unified action

Ultimately, the challenge is immense but so is the opportunity. Scaling retrofit effectively to meet the 2050 net-zero targets isn’t impossible, but it does depend on our willingness to treat performance measurement as fundamental.

This means adopting robust standards, enforcing best practice to prioritise actual savings, and making an industry-wide commitment to getting retrofit right first time, every time.

The NAO’s damning report should not be a reason to despair, it should serve as a catalyst for change. We have the technology, evidence, and expertise at our disposal. But what we need now is the collective will to prioritise quality over quick wins, real-world outcomes over political targets, and genuine performance over empty compliance.

The future of fair, effective retrofit depends on it.