GBIS (Great British Insulation Scheme) is an important supplier obligation program, running from April 2023 to March 2026. Although it will be fully operational by the summer of 2023, it is currently in the Early Delivery stage, granting some access before full implementation. Ofgem administers this scheme and it is funded by medium to large energy companies. Unlike the ECO scheme, which adopts a "whole house" approach, the GBIS will primarily focus on delivering single insulation measures, such as loft and cavity wall insulation.