Recognition of Geometrical and Proportional Principles in Open and Semi-Open Spaces of Hot and Humid Climate (Case Study: Historical Houses of Bushehr)1

Proportion is one of the significant design principles featured in Iranian architecture. Several factors are influential in applying a certain type of spatial proportions. Climate and ecology are the most important ones. Bushehr is one of the cities in the hot and humid climate in Iran and features historical houses which include a large variety of open and semi-open spaces. The general appearance of the mentioned spaces in the historical buildings shows that the proportions of these spaces apparently follow certain principles. Therefore, this research was conducted with the aim of studying the proportional and geometrical principles used in the open and semi-open spaces in the historical houses in Bushehr. The findings and the results of the research can be used by contemporary architects and designers. The research is organized in two parts: the theoretical foundations and the fieldworks. In the theoretical basis part, the archival method was used to introduce and examine the history and the functions of these spaces. In the fieldwork part, the direct observation was the main method. The study of existing building drawings and their adaptation to the numerical measurements using laser meter were the next steps. The findings obtained from the geometry and the extracted numbers and sizes show that the open and semi-open spaces of the historical houses in Bushehr do not follow the proportional principles which, conversely, are common in other regions of Iran. However, the open and semi-open spaces have similar proportional geometry in all cases. The courtyard spaces have a square geometry or close to it, with a high height to width ratio. The height to width ratio in the corridors, arcades and “Tarmehs” is large and about the number three, in order to create more depth for shading. The dominant geometry of semi-open spaces is elongated rectangle in shape, their height is high, and their proportions are close to the number four in order to accelerate the convection of the heat upwards.