Our designed projects often do not perform in reality. This disparity between predicted or designed and achieved performance in reality is referred to as a ‘performance gap’. Performance is often thought if as a technical pursuit relating to building and system performance only (i.e. focus on energy and CO2 issues), but it also includes material, spatial performance and occupant satisfaction. There are many reasons for this gap, and include assumptions made at design stage, use of tools that are ill-designed for predicting performance, workmanship and commissioning issues and complex/smart technology as well as occupant behaviour and procurement models and design processes itself that do not embed post-occupancy monitoring, removing the design team from the end-user (that the design assumptions are based on). Meeting intended performance in building design and construction is crucial to meet ambitious and necessary climate goals, and meeting the EU’s stringent regulations for reducing energy consumption and CO2 emissions.