Retrofit training failures leave homeowners in the cold

The UK’s ambition to retrofit 19 million homes by 2050 depends on one thing: people who know what they are doing. A new report, as reported by Construction News, slams the training system as ‘dysfunctional’, a word that should worry every homeowner planning an eco upgrade.

What the report found

The investigation reveals a patchwork of training courses, some lasting days, others weeks, with no consistent standard for assessing competence. Of the 30 courses reviewed, several lacked practical assessments. One provider offered a ‘retrofit coordinator’ qualification entirely online, with no site visit required. The report’s authors found that trainees could pass without ever handling insulation, sealing a draught, or checking a heat pump’s refrigerant charge.

For a homeowner spending £10,000 on cavity-wall insulation or £7,000 on an air-source heat pump, that is a direct risk. A badly fitted heat pump can consume 30% more electricity than a properly installed one, adding roughly £150 a year to a typical 3-bed semi’s bill, according to Energy Saving Trust estimates. Poor insulation can leave cold spots, condensation, and mould, negating any EPC gain.

Who qualifies, and who doesn’t

Government schemes such as the Boiler Upgrade Scheme and the Great British Insulation Scheme require installers to be certified under MCS (Microgeneration Certification Scheme) or PAS 2035. But the report suggests these certifications are only as good as the training behind them. PAS 2035, introduced in 2021, was meant to raise standards. Yet the Construction News investigation found that some training bodies are ‘accredited’ by organisations that themselves have minimal oversight.

The catch is that a certificate on the wall does not guarantee competence. A homeowner who hires a PAS 2035-qualified installer may still get a substandard job if that installer’s training was a tick-box exercise. Ofgem’s own data shows that 12% of heat pump installations under the Renewable Heat Incentive failed initial quality checks, a figure that aligns with the report’s concerns.

What it costs a typical 3-bed semi

A full retrofit, loft insulation, cavity walls, double glazing, heat pump, solar panels, can run £25,000 to £40,000. Grants cover some of that: the Boiler Upgrade Scheme offers £7,500 towards a heat pump; the Great British Insulation Scheme pays for basic insulation. But if the work is done badly, the homeowner loses not just the grant but the expected savings. A heat pump that cycles on and off because it is oversized or poorly commissioned can cost £500 a year more to run than a well-installed one.

The Energy Saving Trust recommends asking for at least three quotes, checking references, and insisting on a detailed commissioning report. The report’s findings make that advice urgent, not optional.

What homeowners should do now

First, check your installer’s credentials on the MCS website or TrustMark portal. Second, ask for evidence of practical training, not just a certificate. Third, demand a written guarantee that covers both parts and labour for at least two years. The government’s own ‘TrustMark’ scheme requires this, but not all installers comply.

If you are planning a retrofit in 2025 or 2026, wait until the new ‘Competent Person Scheme’ for retrofit is fully rolled out, expected by late 2025. Until then, the safest route is to use installers who are members of the National Insulation Association or the Heat Pump Association, which have their own codes of conduct and complaint procedures.

Households on standard variable tariffs can check eligibility for grants through gov.uk. Applications for the Boiler Upgrade Scheme remain open until 31 March 2027. But do not rush: a bad installation costs more than a delayed one.