Review of the Geometry and Proportions of the Central Court in Achieving the Right Daylight in the Ghajari's Historic Houses of Kashan

In the central yard of historic houses of Kashan, geometry and proportions are the most important factors in providing light to adjacent spaces. To measure the optical performance of these yards it is necessary to know its geometrical properties. The article by the method with expression of geometric and proportional principles and rules related to the central yard in the use of daylight spaces, proportional to its performance in the selected sample. Factors such as geometric shape, length, width, height and specific ratios R_1= ambient / height and R_2= width / length or (PAR), SAR = width / height, sky boundary and angle of view of the sky relative to the pop-up and its effect They are based on the optical performance of the yard. The results show that the dominant geometry of yards, rectangles and squares is with corners Proportional values R1, R2 exceed the suggested minimum for proper illumination of space; Also, the SAR and the viewing angle of the openings to the sky are proportional to the performance of the spaces and the need for their lighting. As a result, in Kashan homes, light is given higher priority than its climatic function, and adjacent central yards enjoy natural daylight and almost uniformity with adequate light penetration for most of the day. Yards are able to provide a daylight factor of more than 1.5-3 for adjacent spaces, which indicates the compliance of its geometry, proportions and spatial scale in order to provide adequate lighting for these houses.