In the Voldsløkka school concrete was used in critical parts of the structure, replacing it with wooden structures in other parts of the building load-bearing structure. In general, there are several technical challenges associated with concrete where high amounts of cement are replaced by supplementary cementitious materials (SCMs). With reduced cement content and increasing amounts of other additions, the early strength as well as the long-term strength development can be reduced. Some durability properties might be also reduced. Resistance to alkali silica reactions as well as chloride ingresscan however be increased for properly cured concrete with low carbon binders. On the other hand, resistance to carbonation in buildings and frost-salt scaling in infrastructure concrete may decrease and remains a challenge. High replacement of cement with SCMs in low carbon concrete can also affect the workability (flow properties) and handling of the concrete.