The 8th International Conference on Building Materials and Construction (ICBMC 2023, Kyoto, Japan, online during March 17-20, 2023) and the 7th International Conference on Materials Engineering and Nano Sciences (ICMENS 2023, Chiba University, Chiba, Japan, online during April 7-10, 2023) were successful events with a strong academic atmosphere, which helped participants to exchange scientific and technological ideas. This edition is compiled from the results of these conferences and presents the latest research results on biopolymers, composite materials, chemical technologies, electro- and photochemistry, green building materials and structural mechanics.