Definition
ECO4
Energy Company Obligation, version 4 — the UK government grant programme that funded much of the now-problematic spray foam insulation across UK lofts between 2022-2026.
ECO4 ran from April 2022, providing energy-poor households with grant-funded retrofit insulation.
Spray foam was a popular choice because it qualified and could be applied quickly.
By 2024, mortgage lenders updated their policies to refuse properties with spray foam, leaving many ECO4 homeowners unable to sell, remortgage, or release equity.
Government has confirmed (March 2026 Commons Library briefing) there is no universal scheme funding ECO4 spray foam removal.