The making of colored glass windows flourished during the Safavid period (1501-1736 AD) and became an inseparable feature of traditional Iranian architecture that was greatly concerned with climate and use of natural resources. Orosi, Arasi or Orsi windows offered a suitable interior temperature, shade, controlled natural light, heat insulation and natural ventilation. But they also became a valuable artistic and decorative element in architecture of northern, central and southern Iran. In western literature, Persian colored glass panels (Shisheh-Alvaan & Mushabbak) and Orsi or sash windows and their periodically significant role in the traditional architecture of Iran as cultural, environmental and climatic elements of architecture, is missing. Unlike classical western architecture, where stained glass is highly embellished within a Christian context, it served a greater purpose in Iranian architecture that is rarely explored. Today there is very little known about the techniques craftsmen used in Iran to construct beautiful colored glass windows and panels. The origin of Orsi is unknown and there isn't any substantial research conducted in the area of colored glass windows in Iran. Through examination of original and primary archival manuscripts, existing historic monuments and contemporary literature. My research aimed to explore the origin, design and climatic effects of Orsi windows and colored glass panels in Persian architecture from the Safavid era forward.