This report delves into the application of structural lightweight concrete for thermal energy storage, adhering to Australian Standards. It examines compressive strengths of concrete, crucial for understanding its characteristics and proper implementation in structures. The report discusses mix design challenges for structural lightweight concrete, particularly in maintaining workability while minimizing water content, and introduces methods like the "specific gravity factor" and volumetric approaches to address these challenges. Furthermore, it explores the use of porous materials with reversible chemical and physical sorption properties for long-term thermal energy storage in buildings, highlighting the importance of micro- and meso-porous materials and providing examples such as zeolites and organic/inorganic porous hybrid materials. The report references key studies and publications in the field, providing a comprehensive overview of the subject.