Lessons from Sustainable and Vernacular Passive Cooling Strategies Used in Traditional Iranian Houses

Passive cooling strategies have long been used in vernacular and traditional architecture practices. Today, with the surge in energy consumption, excessive carbon emissions and lingering climate change challenges, the shift to passive solutions to heat and cool buildings is crucial. Despite this urgency, we heavily rely on electricity and gas to maintain thermal comfort inside buildings. Since heating and cooling accounts for 40% of household energy use, devising passive strategies in housing design can make a significant difference in energy consumption. This paper explores the characteristics of Iranian traditional housing that contribute to making indoor spaces thermally comfortable. The examination of sustainable strategies used in seven case studies in the hot and dry climate of Iran indicates that such measures have a significant impact on the microclimate of traditional houses and considerably reduce the need for electricity and mechanical power. The study suggests that designing tall, north-facing walls, large and shallow pools in the courtyards, multiple openings in the courtyard-facing wall in the same room, stack-cooling for instigating the convective air movement, night purge ventilation, dome ceilings, earth coupling and using thermally massive materials, as well as seasonal relocation across the courtyard are among the most important strategies for mitigating the heat in Iranian houses. Finally, this work puts forward a set of recommendations to improve the passive design of future buildings in hot and arid climates.