The role of complexity in preference for and familiarity with two-storey traditional and modern house facades has been explored. Two sets of (8 traditional, 8 modern) house facade drawings, each representing minimum, intermediate and maximum complexity levels were prepared. Seventy-two Turkish university students (36 males, 36 females) from architecture and non-architecture departments rated these 16 drawings and 5 buffers on 7-point semantic differential scales, consisting of 'beautiful-ugly: 'pleasant-unpleasant: 'liked-did not like: 'simple-complex: 'plain-ornate: and 'familiar-unfamiliar'; and specified their most and least liked drawings among each of the modern and traditional sets of houses. Results indicated that the manipulated complexity levels were perceived as intended and the relationship between complexity and preference was an inverted U-shape, such that drawings representing the intermediate level of complexity were favored over the most and the least complex ones. The intermediate level of complexity appeared to be the most complex level within respondents' range of familiarity because they were equally familiar with houses of minimum and intermediate complexity levels, but their familiarity decreased for houses of maximum complexity level, as did their preference. The general pattern of these relationships seemed to be valid for different measures (rating and preference), respondents' background (architecture and non-architecture), and house types (traditional and modern), in spite of some minor differences. (C) 2000 Academic Press.