Learning from Javanese vernacular theater architecture: passive natural ventilation strategies in a tropical humid climate

Abstract

Tropical vernacular heritage buildings serve as repositories of generations of embodied climate wisdom, yet their passive environmental performance remains poorly documented. The research explores the thermal performance and natural ventilation strategies of the Sobokartti Theatre in Semarang, Indonesia. This theater is a conserved heritage building of Javanese origin and features a hybrid colonial vernacular spatial layout that combines the Joglo and Limasan typologies of the roof. The research uses a five-lens triangulation framework consisting of archival analysis, in situ observation, quantitative field measurements, computation-al fluid dynamics (CFD) simulation, and thermal comfort assessment utilizing PMV, ASHRAE Standard 55, and the Indonesian National Standard (SNI). Field measurements showed mean interior air velocities of 0.54–0.68 m/s and in-let-to-outlet temperature differences of 0.7–1.1°C. The multistage Joglo roof acts as both a wind scoop and a stack-effect driver, resulting in aperture velocities of 0.40–0.53 m/s. The CFD simulation proved the conceptualized thermal moderation of a vertically arranged air flow system. Even when PMV values reached 2.1–2.2 during peak hours, thermal tolerance of occupants was between 72% and 89%, indicating a significant adaptation capability of users of tropical buildings. The building’s environmental performance is the result of a coherent interplay between the configuration of vernacular architecture, natural ventilation and the relationships between the occupants and the environment. This paper proposes a replicable framework for the assessment of naturally ventilated heritage buildings as integrated environmental systems. It argues that conservation should not be only about physical authenticity but also about the transmission of embedded climatic intelligence for the sustainable low-energy design of architecture.