Objective  This research aims to understand the distinctive construction techniques used in traditional mountain dwellings for adapting to regional climate changes. The correlation between these techniques and the intricate factors influencing them is explored, in hope of offering insights into the low-energy consumption, green design, and climate adaptive transformation of contemporary regional structures.

Methods  This research takes the dwelling clusters in Jingtong Village, Youxi County, Sanming City, Fujian Province as the research object, where the regional climate is hot and rainy in summer and mild in winter. Due to this, the primary goal of local construction techniques is to ensure optimal natural ventilation to improve thermal comfort in summer. Based on field research and interactions with local inhabitants, homeowners and artisans, the research reveals that local dwelling clusters are mostly sited against a hill or valley, with horizontally parallel alleys, expansive and descending courtyards, and low-lying and deep gables, mainly for purpose of “shading and air guiding” in summer. As such, this research prioritizes natural ventilation in summer over other seasons. Utilizing on-site measurements and meteorological data, the research adopts a “step-by-step simulation” method for computational fluid dynamics (CFD) analyses of local dwelling clusters at the two scales of cluster and unit. This approach can facilitate both qualitative and quantitative assessments on the ventilation characteristics of such dwelling clusters in summer. Additionally, the research conducts an initial examination on the determinants of natural ventilation across six traditional dwellings, mainly considering the uniformity and divergence of their construction. With Houlongcuo (a kind of wing-room) as a benchmark, the research develops four comparative models to compare the face widths of the primary and secondary patios, eave depths, and cornice height discrepancies, and accordingly elucidate the interplay between “courtyard configuration” and the natural ventilation of traditional dwellings in summer, thus identifying the optimal courtyard dimensions for ventilation.

Results  The research findings reveal that: 1) Local settlements are strategically located on the gentle inclines of river valley terraces and mountain hillsides. Given regional climate, emphasis is placed on the spatial orientation of macro landscape pattern following the principle of optimal ventilation flow. 2) Local dwelling clusters still maintain the advantages of individual spatial units. Such factors as mountain shape, structural orientation, overall layout and natural barrier may jointly influence the ventilation efficacy of traditional dwellings. The mountain topography either funnels or obstructs airflow, altering wind speed and direction around the traditional dwellings. Building orientation is predominantly influenced by landscape, for which a “design by circumstance” approach is adopted without strict adherence to directional principles. Most structures face southward with possible slight deviations eastward or westward to capture prevailing winds. The incorporation of east-west wells and alleys compensates for reduced airflow in dwellings not aligned from north to south as traditional dwellings, ensuring high wind speed level. Architecturally, the consistent layout among the six dwellings stems from the grand lineage’s religious system, which can promote consistent ventilation patterns. In spite of the variationsin natural ventilation characteristics among spaces, all spatial configurations cater to the inhabitants’ needs. The layered structure design minimizes wind speed differentials across “three halls and five buildings”, promoting consistent and comfortable breezes. 3) Structures are designed in harmony with the surrounding environment, with shape, size and height differentials being considered to ensure optimal ventilation. Changes in the face width of the primary patio show an insignificant correlation with wind speed readings. However, enlarging the side patio augments wind speeds around the water-crossing pavilion. As patio depth increases, indoor average wind speed diminishes, particularly noticeable in the lateral water-crossing pavilions. The velocity metrics across the “three halls and five buildings” initially rise, then decline. Terraced designs in the rear alleyway counterbalance the difference in mountain elevation, with each terrace rising by 0.82 m, culminating in a gable height differential of 3.14 m. This is consistent with mountain gradient, thus directing airflow efficiently through the main hall and maximizing daylight exposure.

Conclusion  This research comprehensively examines the features and determinants of natural ventilation in summer across traditional mountain dwellings in central Fujian at various scales. It reveals that these dwellings are interconnected and progressively layered at multiple scales to achieve optimal summer ventilation. This approach embodies the region’s ingenious strategies for low-energy climate adaptation. The systemic and continuous nature of these strategies proves essential for harmonizing with the natural climate.