Atria and open stair connections between floors form part of the design aspirations for many modern office buildings. These features introduce a risk of fire affecting multiple floors simultaneously, which can threaten the structure in different ways to a single floor fire, particularly for steel frame structures. This study investigated the challenges, the practical considerations and possible approaches to evaluating structural fire behaviour in multi-floor fires, as well as design measures which can be implemented to address the risks. The study was conducted based on a case study from a recent Arup commercial project.