T: Saving energy and resources has become a major issue in the design of machines and new developed plant concepts in the AAC production. For many years WEHRHAHN has been focusing on solutions in view of sustainability and effi ciency. The comparison of two AAC plants –of different generation- at RDB Hebel in Pontenure, Italy provides detailed information concerning the effect of action taken in recent years to reduce energy and raw material consumption. The evaluation considers of identical basic raw materials and the same applicable AAC standards a) The fi rst plant was built in 1986 Type Hebel for block production, capacity 1.080 m³/day b) The second plant was built in 2008 Type Wehrhahn PLUS 1400, capacity 1.400 m³/day for block production The following parameters have been compared [1]: – Product quality of the AAC, density, compressive strength, rejects, – Raw material consumption, – Energy consumption, – Labour cost. In the conclusion the results of the investigation have been discussed and an outlook into the future of a sustainable AAC production has been given.