<![CDATA[This study examines the passive strategies of the Rumah Gadang and their influence on thermal comfort in a hot-humid tropical climate. The research was conducted to identify the passive elements of two Rumah Gadang buildings and to evaluate how these elements affect indoor thermal conditions. A mixed-method approach was applied through qualitative observation of building elements and quantitative measurement of air temperature and relative humidity at eight points over 13 days, converted to Standard Effective Temperature (SET) following the Gagge two-node model specified in SNI 9382:2025. The results indicate that both buildings apply passive elements such as building form, orientation, roof, overhangs, openings, raised floor, wooden walls, columns, foundations, interior spaces, open space, and surrounding landscapes, which contribute to temperature regulation and natural air movement, especially through the stilt-house system, openings, and underfloor space. Rumah Gadang Istano Rajo Rantau XII Koto (RG2) records lower peak air temperatures and more stable, more evenly distributed temperatures than Rumah Gadang Sikumbang Tuanku Rajo Malenggang (RG1); however, when evaluated through SET — which more fully captures the physiological effect of humidity — RG1 sustains a marginally longer average daily duration of neutral/comfortable conditions (9.0 hours) than RG2 (7.5 hours), as RG2's persistently higher relative humidity offsets much of its temperature advantage. In both houses, the roof remains the hottest part of the building, and relative humidity in both cases remains above the comfort standard throughout the measurement period. These findings confirm that Rumah Gadang is not only a vernacular cultural heritage but also a relevant reference for passive tropical architecture, and that humidity control — not temperature control alone — is essential to advancing environmentally responsive, energy-efficient building design derived from vernacular precedent.]]>
