The process of commissioning and planning a new building can be complex, requiring a combination of skills, expertise and motivation from several different stakeholders. The first article in this series on healthcare infrastructure made the case for more modular facilities in the NHS, to increase capacity and help services address the growing care backlog. This article, the second in a series of three, will discuss the process of commissioning a modular facility, drawing on two in-depth case studies to provide insight from healthcare managers who have successfully completed such a project. This includes exploration of the circumstances that led the trusts to consider a modular solution, the challenges they faced, how they overcame those challenges and the benefits they have observed in their services so far. A guide to the key considerations and recommendations for commissioning and planning a modular facility is also provided for trusts looking for ways to expand their service capacity.