A government report evaluating the impact of the Green Homes Grant Voucher Scheme (GHGVS) – which was supported by SERL data and expertise – has been published.

The evaluation

The report – released by the Department for Energy Security and Net Zero (DESNZ) on 2nd November 2023 – evaluates the outcome and economic impact of the GHGVS. One of the four ‘Green Economic Stimulus’ programmes announced in July 2020, GHGVS offered homeowners a voucher for up to two thirds of the cost of home energy efficiency improvements as part of a drive to maximise job retention, grow the UK retrofit market and tackle fuel poverty while addressing environmental goals.

The research

DESNZ partnered with Ipsos MORI, the BRE Group and the Energy Saving Trust as well as UCL researchers (including the SERL team) on the evaluation project. The SERL observatory sample of 13,000 participating homes was used as a control group to measure the GHGVS homes against. Machine learning regression was used to isolate the effects on a measure-by-measure basis, allowing for an estimated average energy saving
to be calculated for each measure.

“Robust evidence”

The evaluation identified “robust evidence of participation in GHGVS generating energy, carbon, and bill savings, but savings varied by measure type. Air source heat pumps and external solid wall insulation generated clear savings in energy, with associated reductions in carbon emissions and consumer energy bills. By contrast, whilst solar thermal was one of the most-installed measures through the scheme, it did not produce observable effects on energy consumption.”

The GHGVS report and evaluation are good examples of the way the public investment in SERL has enabled real-world data to be used in evaluating the effectiveness of intervention programmes.

Access the full report: Green Homes Grant Voucher Scheme: evaluation – GOV.UK (www.gov.uk)

View other SERL-related publications: SERL key documents