Twelve million UK homes need retrofitting to meet net-zero targets, yet fewer than 2% of installations meet the promised energy savings. That is not a policy failure, it is a policy design failure. The government has chased quantity over quality, and homeowners are paying the price in higher bills and lower EPC ratings than they were sold.
As Construction News reports, the UK’s retrofit programme is now being scrutinised for its obsession with volume, how many homes treated, how many heat pumps installed, rather than whether those homes actually consume less energy. The catch is that this volume-first approach has left a trail of substandard work that the taxpayer will ultimately underwrite.
Why volume-first fails the homeowner
Consider a typical 3-bed semi in Manchester that received cavity-wall insulation under a government scheme. The installer used substandard materials, leaving gaps. The householder now sees no reduction in their gas bill, still around £1,200 a year, and the EPC remains at D. Ofgem estimates that poorly installed insulation alone costs UK households £180 million annually in wasted energy. That is £180 million of public money that achieved nothing measurable.
The problem is structural. Contracts are awarded on numbers of properties treated, not on kilowatt-hours saved. Installers are incentivised to move fast, not to do the job right. The Energy Saving Trust has long argued that a quality-assured retrofit should include a pre-installation survey, a detailed specification, and a post-installation performance test. Currently, fewer than one in five schemes include all three.
What a quality-first policy looks like
The shift is straightforward but politically uncomfortable. First, government must mandate that all retrofit work is carried out by PAS 2035-certified installers, the current standard, but one that is often ignored. Second, every installation should come with a performance guarantee: if the home does not achieve the predicted energy saving, the installer pays the difference for three years.
Third, the EPC system itself needs reform. A home that receives a new boiler but no insulation can jump from E to C on paper while actual energy use barely changes. The government’s own consultation on EPC reform, due later this year, must align the rating with real-world consumption, not just modelled assumptions. Until that happens, homeowners cannot trust the label they are sold.
What homeowners should do now
While policy catches up, individual households can act. Prioritise fabric-first upgrades: loft insulation (typically £300–£400, saves £200 a year), wall insulation, and double glazing. These deliver reliable savings regardless of installer quality. When choosing a contractor, ask for PAS 2030 or PAS 2035 certification, and request a post-installation thermal imaging survey. If the installer refuses, walk away.
The government will open a new round of the Boiler Upgrade Scheme in April 2025, offering £7,500 for heat pumps. But only use this if your home is already well insulated, otherwise the heat pump will run inefficiently and your bill may rise. The Energy Saving Trust’s home energy check tool (free online) can tell you your home’s heat loss before you commit.
Retrofit policy will change. The question is whether it will change fast enough to stop the next wave of wasted spending. For now, the safest retrofit is the one you supervise yourself.
Frequently Asked Questions
Ask for their PAS 2030 or PAS 2035 certification, which covers installation of energy efficiency measures. You can also check the TrustMark registered installer database, all government-funded schemes require TrustMark accreditation.
Initially, yes, quality-assured work costs 10–20% more upfront. But the Energy Saving Trust estimates that poorly installed measures waste £500–£1,000 in extra energy bills over five years. A quality-first approach pays for itself within three years through guaranteed savings.
