This annual report presents detailed statistics on the Energy Company Obligation (ECO), the Green Deal (GD) and insulation levels in Great Britain, up to the end of 2018. This is the fourth annual release following the user consultation that took place in autumn 2015 on GD, ECO and insulation level statistics. It includes further analysis and geographical breakdowns of ECO measures. It also includes ECO delivery costs, estimated carbon and energy savings from measures installed, the GD supply chain, and estimates of home insulation levels. These statistics are provisional and are subject to future revisions.