Understanding the Performance of the Iraqi Traditional Courtyard House, Is there an Order for the Use of External Envelope Materials?

Until the late decades of the nineteenth century, The Iraqi traditional courtyard house (ITCH) had ensured social, cultural, and environmental needs. Although many researchers had documented the ITCH characteristics and features, the strategy of materials use of its walls and roof slabs has not been recorded as a system or an order yet. This paper believes that the ITCH has an inherent order for its walls and roof slabs materials use. The research methodology, to explore and extrapolate this order, includes investigating and analyzing photographic and descriptive surveys of the ITCH documentations. Results reveal that the order comprises the use of the two types of components; the thick and heavy walls and roof slab with the thin and lightweight ones together simultaneously in appropriate specific positions of the ITCH. The order also expresses a harmony between the material properties of the envelope components and their exposure to the environment. Thick and heavy walls and roof slab are used in places where they are mostly shaded, whereas thin and lightweight ones are used where they are exposed to sun. The order was simulated in a diagrammatic house model.