The series of catastrophic mistakes made in the design of the non-domestic Renewable Heat Incentive (RHI) have been widely reported since the NI Audit Office published the first report into the scheme in July 2016. Since then, revelations continue to emerge through the ongoing public inquiry.However, aside from the design, rollout and ultimate closure of RHI in February 2016, officials in the Department for the Economy (DfE) are still making fundamental errors in their handling of RHI as they attempt to reduce scheme overspend.