Bio-based buildings, including massive wood structures and timber-frame constructions, offer high efficiency in winter, providing excellent thermal comfort with minimal energy demand for heating. This study investigates hygrothermal measurements conducted on real-scale walls constructed using innovative multi-layer panels created from functional bio-composites. These panels can be manufactured using recycled waste from the production site and wood waste from construction demolition. The experimental facility is a test hut constructed in Latvia, with humidity and temperature sensors strategically placed within the walls. An analysis of the results for three different wall configurations is undertaken to verify the monitoring and offer a first comparison of the construction systems. The results enable a better understanding of hygrothermal interactions within the walls under real outdoor climate. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.