Optimization of rural green building design in Northwestern Hunan based on LCA and AHP

Rural buildings in northwestern Hunan face multiple challenges in achieving a green and low-carbon transition, including fragile ecological environments, limited access to resources, and strong cultural preservation demands—rendering existing urban-based green building strategies largely inapplicable. To address these issues, this study develops an integrated evaluation framework combining Life Cycle Assessment (LCA) and the Analytic Hierarchy Process (AHP), aiming to facilitate the green transformation of rural architecture in the region. Based on field surveys and simulation modeling of 24 sample buildings, findings indicate that carbon emissions across the building lifecycle are predominantly concentrated in the material production and operational phases, jointly accounting for over 85% of total emissions. Among the three building types, traditional timber dwellings exhibit the lowest total carbon footprint (34,875.5–47,184.0 kg CO₂-eq), followed by modern energy-efficient houses (91,284.0–117,908.5 kg CO₂-eq), while brick–timber hybrid structures show the highest emissions (99,300.0–139,020.0 kg CO₂-eq). AHP-based weight analysis identifies “Resource Efficiency” and “Environmental Livability” as the two most influential dimensions, with a combined weight of 0.699, underscoring their pivotal role in shaping green performance. Accordingly, the study proposes differentiated low-carbon optimization pathways: traditional buildings should focus on utilizing locally sourced low-carbon materials and passive ventilation strategies; modern structures should prioritize operational energy efficiency; and brick–timber hybrids require targeted energy retrofit interventions. The results validate the scientific robustness of the LCA-AHP hybrid model and enhance its regional applicability through localized parameter adjustments, offering a quantitative foundation and optimized pathway for advancing sustainable rural building design in ecologically sensitive areas.