Land should be one of the greatest assets of the UK healthcare system, as a result of its large estates portfolio. Howere, the current state of many of the NHS's buildings means that physical spaces are often more of a burden, with maintenance backlogs costing billions. However, as a resource-limited public institution, it is crucial that all investments into NHS infrastructure are as effective and future-proof as possible. The previous two articles in this series have focused on the potential benefits of modular facilities to healthcare staff, services and patients, drawing on case studies of NHS trusts that have implemented modular facilities on their sites. This article, the third and final instalment of this series, discusses the health economic impact of current NHS infrastructure, and explores the ways in which modular facilities could provide a flexible and cost-effective means of expanding capacity and improving services in a resource-limited environment.