Dances with Shadows: A Retractable Wood Cover of a Courtyard in Historic District of Yazd

The significance of shade in sweltering climates for sustainable living is underscored by the vernacular architecture of Yazd. Through a central water body, a tree canopy, and structures that encircle the courtyard, courtyards offer shade within the urban fabric of Yazd. These courtyards generate positive pressure, which propels cool air into interior spaces, thereby establishing a cool microclimate. Cool air from the courtyard replaces warm air extracted through high ceilings, windcatchers, and other exhaust systems. This design strategy reduces interior temperatures by implementing a natural ventilation system in arid regions. A Yazd courtyard’s underground substructure, however, compromises its ability to generate shade and cool air. The retractable wood cover over Yazd University’s courtyard named ‘Ellieen’ is the subject of this chapter’s description and analysis of a recent design-build project. The cover’s design generates dynamic shadows on the courtyard surfaces, adding a new aesthetic element to the context. The project’s main purpose is to address the increasing need for improved comfort in traditional courtyards during hot seasons, driven by climate change and the need to adapt existing structures. Additional considerations are shade optimisation during the day by its changeability; material selection for the cover should prioritise heat reflectance, ventilation, and durability. Integration with architecture is important too. The courtyard cover should seamlessly integrate with the overall architectural design, complementing the aesthetics and functionality of the historical building. The concept of temporarily covering open spaces and yards in Yazd dates back to the past, with fabric covers called ‘Poosh’ used to shade religious places. To achieve the goal, the project attempts to shade the courtyard the courtyard via a cover, known as one of the open spaces of the Art and Architecture School. The courtyard is 10 m × 13.80 m2 in size. There is no tree since the courtyard has a subterranean level under it as a library. Around the courtyard, there have been various activities, including a buffet for students and a prayer room. In addition, this courtyard serves as a link between other courtyards of the faculty complex houses. The design problem involves lightweight, responsive courtyard coverings that retain the original mass and space while allowing for a variety of activities in the courtyard while matching the historic district’s skyline. The design-build process of the prototype resulted in a telescopic cover that can collapse into a convex shape. It features wooden beams in the larger courtyard and metal rails on the smaller sides. The mechanism opens the upper half of the cover with the help of an electric motor, exposing half of the courtyard surface. A shorter half-cover is then fitted inside. The two sections move simultaneously and completely out of the courtyard’s opening, repeating the process in the opposite direction. By using only wood, the design spans a distance of 13.8 m, demonstrating the structural capabilities of glued laminated timbers. The involvement of students in the construction of the shade structure at Yazd University’s Faculty of Art and Architecture went beyond mere labor contributions. It had a profound impact on both the students’ sense of belonging to their academic community and the overall project management process. The decision to engage students in the construction of the shade structure aligns with a cornerstone of vernacular architecture, which is leveraging local labor with preservation skills and knowledge.