Over recent years, alkali-activated materials (AAMs) have been regarded as potentially lower carbon footprint alternatives to Portland cement binders, with a role to play towards the decarbonization of the built environment. The use of low density AAMs seem particularly promising extending the application range of these novel binders to other high added value applications including their use as thermal and acoustic barriers, moisture regulators, and thermal energy storage materials. These additional functionalities have the potential to further contribute to the reduction of energy consumption and the improvement of living conditions. Herein, the most relevant and recent research focusing the use of lightweight AAMs in the built environment is summarised and critically discussed.