Accounting for more than a third of global energy demand, the built environment has a crucial role to play as we work towards the goal of zero-carbon energy. However, the complex nature of buildings means it can often be difficult to pinpoint where energy efficiency strategies and decarbonisation investments can be implemented with greatest impact. This presentation will explain how dynamic simulation technology and digital twins can serve as a vital tool in supporting built environments in their energy efficiency and decarbonisation journeys. IES and Auditel will share lessons learned from real life case studies, delivered through a joint approach, to demonstrate how more sustainable, energy and carbon efficient buildings can be realised. Maximising opportunities to reutilise waste energy and reduce energy costs.