Beyond Low-Carbon Buildings: Implementation, hygrothermal Performance, and LCA of poured earth and straw construction in rural China

• A regenerative building employing poured earth and biobased materials was constructed. • Hygrothermal performance throughout the year was assessed through on-site monitoring. • The whole life carbon emissions of the prototype building were evaluated. • The benefits of employing regenerative materials were thoroughly discussed. As one of the largest carbon-emitting sectors, the building industry’s transition toward carbon neutrality is critical to achieving global climate goals. Earth and biobased materials, usually considered as regenerative materials, offer a promising strategy for reducing both embodied and operational carbon, yet their scalability remains insufficiently documented in real construction. This study showcases a full-scale prototype building in a cold climate region of China, examining its construction system, indoor hygrothermal performance, and carbon emissions. Specifically, an innovative hybrid “light steel-straw-poured earth” construction system was developed, with embodied carbon quantified through on-site documentation of materials and construction processes. Indoor hygrothermal performance was monitored year-round to assess operational emissions, combining monitored data with simulation to provide a close-to-reality assessment. Results show that the hybrid system reduced embodied carbon by up to 28% compared to conventional concrete-brick rural buildings. Long-term monitoring demonstrated substantial improvements in indoor environmental stability: indoor temperature fluctuations were reduced by more than 70%, and relative humidity remained within the 40%-60% comfort range for 85% of the monitored period. Further implementation of timber as a structural bearing can reduce total carbon emissions by up to 40% and net carbon emissions by 86% relative to conventional construction. This study provides a systematic evaluation of earth- and bio-based materials, demonstrating their potential to reduce carbon footprints while improving indoor environmental conditions. The findings support the adoption of these materials as a viable pathway to developing low-carbon, climate-resilient communities in rural China.