The Department for Energy Security and Net Zero (DESNZ) has announced that more than £100 billion in private clean energy investment has been secured since Labour took office. This milestone includes funding for social housing retrofits alongside major national grid upgrades and offshore wind projects.

Following this announcement, DESNZ published the latest Great British Insulation Scheme data, showing that 139,136 retrofit measures were installed across 114,354 British homes between the scheme’s launch in April 2023 and March 2026. The Great British Insulation Scheme (GBIS) is designed to help households insulate their properties, improve domestic energy efficiency, and lower energy bills.

Despite the newly revealed investment in retrofits, the dataset highlights a steady month-on-month decline in delivery. March 2026 saw just 3,571 measures installed, marking the lowest monthly volume in nearly a year.

A Polimapper geodata analysis reveals cross country variations. The constituencies of Leicester East, Redcar, and Blyth and Ashington recorded the highest delivery rates, each exceeding 3,200 measures installed per 100,000 households, alongside some of the highest overall rates of households upgraded.

Conversely, the inner London constituencies of Cities of London and Westminster, Holborn and St Pancras, Islington South and Finsbury, and Kensington and Bayswater have recorded zero energy efficiency measures or household upgrades since the scheme commenced in April 2023.

Sector commentary

Bob Ward, policy director at the Grantham Research Institute of the London School of Economics: “These figures [£100bn] demonstrate the potential scale of green investment, which can drive strong growth in the economy. Private investment is mobilised by clear and consistent policies, and a firm political commitment. It is essential that the next prime minister recognises the power of green investment, and creates an environment to foster it.”

Ed Miliband, secretary of state for Energy Security and Net Zero: “This is only the start of what we want to achieve. From nuclear to renewables, electrification to carbon capture and storage, clean energy can power growth and address the legacy of an economy that hasn’t worked for too many people in too many parts of Britain for too long.”