Autoclaved aerated concrete (AAC) is a widely used environmentally friendly material for masonry units, prefabricated components and insulation boards. Focus of this research is an innovative eco-compatible material, the Bio-aerated Autoclaved Concrete (BAAC), patented by ENEA. The innovation regards the aeration process and involves the complete replacement of the conventional aerating agent (aluminium powder), through the reaction between catalase and hydrogen peroxide, that releases oxygen in the form of bubbles, leading to an increase in volume and the determination of a porous structure. A reduced environmental and economic impact is ensured, on one hand eliminating the use of metallic aluminum powder that is critical in matters of safety, and on the other one, exploiting waste materials from the food and agro-forestry industry for the production of Saccharomyces cerevisiae species derived from common brewer’s yeast. In order to find the best balance between required standards and final performance characteristics, BAAC samples with a density from 350 kg/m3 to 850 kg/m3 were manufactured in laboratory, cured using a homemade autoclave at 180 °C under saturated steam conditions and then characterized by a physical, hydrothermal and mechanical point of view. An improvement in quality parameters is observed, with reduction in density with the same water/solids ratio compared to conventional AAC and therefore better performance in terms of thermo-acoustic insulation, lightness, fire resistance and lower transport costs per unit of volume. The obtained results demonstrate the feasibility and innovation of this green lightweight material useful to guarantee energy saving, carbon neutralization and environmental sustainability.