"Sofa houses are the earliest and remarkable type of houses in domestic architecture of Anatolia. They also present a unique combination of physical and sociocultural features of past civilizations. Despite variations in sofa houses based on climatic, topographical considerations, and local building materials, the evolution process and differences between urban and pre-urban models emerge a typological analysis comprising outer, inner and central sofa types.Outer and inner sofa types present striking resemblance to houses in north Mesopotamia so called "tarma", "riwaq" or "gallery" types. However, the evolution process of each type indicates remarkable differences in urban models.Outer sofa type is primarily considered as an example of the earliest stage of the evolution process, and it also had been the most common type spreaded in Anatolia. Retrospective analysis of this type emphasizes perpetual similarities between Hittite "hilani houses" and early Byzantine "hail" houses in north Syria, and Ottoman "outer sofa" houses. In the chronological perspective, inner sofa houses represent a transition stage situated between pre-urban or urban, and organic or symmetrical example of sofa houses.Other analogical correlations influencing the identity of sofa houses are the tent form of nomadic Turks so called Turkic "yurt" and traditional Horasan house. Theoretically internal arrangement of identical Turkish room might be derived from the meaning and use of Turkic yurt. On the other hand, central sofa houses reflect a specific identity in urban areas which is probably considered as a new version of typical layout of Horasan houses.Generally, sofa houses show a different trend at the evolution basis compare to north and central Mesopotamian houses. The difference between types is not only addressed to the specific characteristics of the house, but also the settlement pattern.This historical research is intended to explore characteristics and the evolution process of the concept of sofa based on examples in past civilizations. Main objectives may be considered to understand original cues about the evolution process, and to articulate specific characteristics or retrospective meanings of the concept of sofa by the enlightenment of cross-cultural comparisons."