The position of Iranian plateau in the southern half of the northern temperate region requires absence of cold weather in this area. However, the average elevation of 1200 meters causes a very cold winter weather as an important feature of this vast plateau. Seasonal variations in temperature which result from a regular change in the angle and duration of the sun's radiation in combination with other climatic factors, give rise to a general need for the sun’s radiation on the surface of passages and depths of houses in many parts of our country during the winter.
Determining the relationship between the angle of the sun's radiation and the directions of public passage network, the height of dwellings and the horizontal distance between the buildings facing each other in terms of the "length" and "direction" of shadow in different occasions of the day play important roles in architectural and urban planning. Attention to this climatic factor in design of new cities and renovation of old neighborhoods of historic cities helps us to take a step towards a comprehensive view of different natural, economic, social and physical dimensions in solving problems of human societies as the " organization of residential spatial system".