Evaluation of Daylight-catching and Daylight Providing Methods in Mosques

Natural light has been an important element in Iranian architecture and shaping the interior spaces of monuments. During different historical periods, the presence of light in various Architectural works, In addition to the functional aspect, has always been under focus from spiritual religious aspects. The incentive to turn to the light during worshiping God has existed in different religions and still exists. Daylight had have a special place and value in Islam and the Islamic worldview. With the emerge of Islam, usage and application of light in architecture increased especially in mosques as the most important monuments of Islamic architecture In mosques, daylight in addition to functional aspect is considered as a mystical symbol and a sign of God's presence that raises the human sense of reverence and humility in front of God. To this end, for centuries, Iranian architectures have been trying to use traditional architectural elements and daylighting solutions to better deploy the natural light in their designs.
This study attempts to investigate and evaluate the application of light-catching elements in Iranian mosques, particularly in mosques and mosque–schools from Qajar period. We use a descriptive and analytical research method and our study is mainly on the basis of resources and the literature available in Iranian libraries. After describing the theoretical foundations of our research, we analyze a number of common light-catching elements in selected mosques. Although a multitude number of studies have been done on the concepts of light and its role and function in the traditional architectural monuments, particularly mosques and homes, little study has been done on light-catching elements in mosques of a specific period as done in this research.
Structural elements which have been used in Iranian traditional architecture for utilizing daylight are studied from two directions. In the first direction, light-catching elements often have the task of transmitting light into the interior space. In the second direction, light controlling elements adjust the entered light into the building (similar to canopies). The subject of this research is in line with the first direction. We only study light-catching elements and we chose among them common elements such as door and window, Shabak, Horno, Rozan and Roshandan. Although these elements are different in term of material, type and location of application in the building, all of them are used for light-catching even though some of them have also ventilation application. We chose 10 mosques and mosque-schools of Qajar period in Tehran. The examined mosques and mosque-schools in this research were selected based on the following criteria: first, all the selected mosques and mosque-schools are located in old and valuable region of the city and they are tourists attraction. They have architectural values and are well-known among people and experts. Secondly, the building of selected samples reflect prominent features of Qajar’s architecture. Also the sufficient information (including maps and images) are available for these monuments. We chose 5 mosques and 5 mosque-schools among Qajar’s architectural works. Then, the usage and the application rate of light-catching elements in these buildings are evaluated quantitatively and qualitatively by the use of maps and the available visual data. Quantitative analysis is based on the approximate numbers of elements used in these mosques which have been extracted from the available images and maps. To qualitatively evaluate the application rate of various methods of light-catching in these mosques, we specify four levels of usage: "insignificant","low","medium" and "high". We provide the results of quantitative as well as qualitative analysis in this paper.
Our analytical studies indicate that although door and window, Shabak, Horno, Rozan and Roshandan had been considered as innovative lighting elements inside mosques of Qajar period, architectures of this period still mainly utilized door and windows as the main lighting elements. Next to doors and windows, Rozan stands at the second place, Horno in the third place, and then Shabak and Roshandan. The utilization rate of doors and windows among considered mosques and mosque–schools has been similar. Nevertheless, the usage of Horno as a lighting element in mosques has been more than mosque–schools, Rozan and Shabak have been used more in mosque –schools rather than mosques. Roshandan has been barely used in the mosque-schools, and only few samples could be found within some mosques of this period.