Nearly one year after the problems emerged, around 3,000 homes with defects had been found and fixed out of the more than 30,000 homes estimate to be affected. TrustMark, the government-endorsed quality scheme, did not notify the Department of high levels of faulty installations of external wall insulation until October 2024, more than two years after the start of ECO4 in April 2022. It highlighted similar concerns with internal wall insulation in November 2024. By mid-September 2025, nearly one year later, less than 10% of the estimated total number of affected homes had been found and fixed.1 TrustMark will oversee the programme to find and fix the remaining homes with faulty external 1 This is based on the midpoint of the estimated range of 32,000 to 35,000. 2,934 remediated homes / 33,500 = 9%. 3 wall insulation, of which it estimates there are around 20,000 as of November 2025. It expects to have audited all relevant homes (providing access is granted) within 15 months of when we took evidence in November 2025. TrustMark and the retrofit sector face a serious challenge in scaling-up audit activities at the pace necessary to meet these timescales. The Department plans to identify faulty internal wall insulation through existing audit processes, but we fear it may be overconfident in expecting this approach to be adequate. It is vital that the remaining homes with defects are found and fixed as soon as possible. As waiting times increase, the likelihood of damage occurring increases, and there are immediate health and safety risks that need urgent attention. recommendation a. In its Treasury Minute response, the Department should set out how it plans to scale-up its find-and-fix programme to meet the 15-month ambition and how it will find all the faulty internal wall insulation. b. Given the severity of the issue for residents of affected homes, the Department should be seeking to deliver the find-and-fix programme within a much shorter timeframe and should updat