Effects of Architectural Design on Daylight Fantasy in Iranian Traditional Houses

Daylight as the only light source in the past was not considered only for its illumination in Iranian traditional architecture. The visual qualities and aesthetics of daylight were other considerations for architects. A good example of fantasy of daylight in Iranian architecture can be found in traditional houses. Diversity of different wall and ceiling openings is a testifier for this claim. To find out the effects of different design concepts in quality and quantity of light related to its specific space, a research has been conducted in Ameri House in Kashan with several central yards and spaces. Discovering the relation between architectural decisions and quality of daylight is the aim of this research. In this article the specifications of daylight in some spaces of this house are studied according to their location in the house, geometric shape of the place, location and condition of their openings related to their functions. Using luminance meter, the field data of several spaces were gathered and it was extended to a year by radiance simulation. Lighting Handbooks were used to analyse lighting conditions such as amount, uniformity or diversity of illumination, visual amenity and visual quality related to the function of the space. The information were analysed in four steps: 1- Room specifications: by calculating “Room Index”, “Room Depth Criteria”, “Perimeter Zone” and “Orientation Factor”. 2- Geometry and neighbourhood conditions: by drawing “No Sky Line” area, “Visible Sky Angle” in section and façade and “Shading Mask” of the window. 3- Analysing the field data: by drawing the “Illumination” contours in plan (on the reference height) and section of each room. 4- The illumination condition of each room in a whole year was simulated using Radiance Software. In steps 3 and 4, the data were analysed by “Useful Daylight Illuminance (UDI)”. It shows the percentage of the room area which is in “UDI Achieved” (100-2000 Lux), “UDI Autonomous” (300-2000 Lux), “UDI Supplementary” (100-300 Lux), UDI Exceeded” (> 2000 Lux), and “UDI Fell-Short” (