Rawshan: environmental impact of a vernacular shading building element in hot humid climates

There has been a recent decline in the use of vernacular building traditions, which have been replaced by modern methods of construction. However, many academics and researchers have emphasized the significance of vernacular architecture, due to such technologies being the result of centuries of experiments focussed on adaptation to local climatic conditions. One of the best-known vernacular architecture elements is the Rawshan (Mashrabiyyah), which is not only aesthetically appealing and improves the indoor environment, but also fulfils a vital social/religious role, i.e. privacy. A Rawshan increases daylight penetration while minimizing energy consumption, thus positively contributing to the wellbeing of occupants. However, in order to optimise comfort, there is a need to reconcile the amount of daylight entering the living space with heat gain during summer and heat loss during winter. This research employed a genetic algorithm to optimise the design of a Rawshan for a residential building, with the aim of enhancing the occupants’ comfort while minimising energy consumption. Grasshopper was used for modelling the residential building and Galapagos for programming and configuring a genetic algorithm. The results reveal that this proposed genetic algorithm-based Rawshan design enhanced comfort, while minimising energy consumption and reducing the negative impact of solar gain on energy consumption