In order to meet the demands of sustainable development the range of cementitious materials used will need to become more diverse. To master the use of this range of materials, modelling has an essential role to play in linking composition and processing to the final properties and performance. This paper describes some of the challenges such modelling presents and progress made at the Laboratory of Construction Materials at EPFL, based on the microstructural models mu ic [Bis09a, Bis09b] and AMIE [Dun10].