Retrofitting domestic buildings is essential for meeting targets to mitigate the catastrophic impacts of our changing climate. Current rates of retrofitting are far lower than necessary for achieving global net zero climate targets. To date in privately owned homes, policymakers have largely relied on piecemeal activity and often short-lived retrofitting programmes and financial incentives. Consequently, this special issue explores what capabilities and capacities are needed to deliver retrofit at scale. Looking across different scales—national, municipal, neighbourhood and individual sites—this special issue provides insights to shape policies, organisational structures and delivery strategies for different scales, building types and supply chain actors. These papers highlight the need for a clearer definition of what retrofit incorporates, alongside the collection of high-quality data and rigorous building metrics. In addition, diverse business models are needed to ensure that a variety of actors across the public and private sectors are well positioned to engage in coordinating building retrofit at scale. Finally, it is essential that any acceleration of retrofitting activity is coupled with consumer protection mechanisms and support for developing supply chains which incorporates both existing workers and encouragement for new entrants. It is only through this multifaceted approach that domestic building retrofit can be delivered at the speed and scale necessary.