"Theory is applicable to classical, interdisciplinary issues on the environmental assessment of public, open spaces. In the field of architectural design professionals, there is a great amount of literature on the link between culture and the built form (Cranz, 2002). Architectural design methodologies have for a long time been struggling with the congruence of fitness of form and function (Lerup, 1998). Recent sociological and cultural anthropology inquires are relevant to balance the scant environmental psychology bibliography available on this kind of the subject. In this paper contemporary issues of modernization, ethnic revivals, globalization, fads and fashions will be presented to demonstrate that these constructs do not ncessarily imply a lack of the designer's stand or awareness on the environmental constraints that they have upon the user's needs. Some open spaces work as expected because they were planned as being socially accountable environments of everyday life, to support human behavior. As it has been the case with historic, traditional environments, when physical form is flexible enough, then public, open-space design can accommodate the dynamism of "timeless" urban life. (Kostof, 1991). Yet, it is assumed that contemporary designers perceive tradition as opposed to modernization. (Rapoport, 1996). Evidence will be drawn from three examples: Torre de les Aigues (Barcelona, Cadira del Bisbe (Barcelona) and Empuries (one of Barcelona's site of the 1992 World Olympic Games). Ethnographic data has been gathered in a longitudinal study of Barcelona's open space system to prove that diversity and cultural change has been considered by the designer at the early stages of the design program. Theory has been used to interpret the data gathered between (between 1982 and 2002) through a set of qualitative studies made on a large user, age-group sample, particularly the young and the elderly. Cultural change has been evaluated through concepts of participatory, decision-making power, cultural distinction, and expressions of culture (e.g. changing "habitus," attitudes and values of teenagers' lifestyles which include participatory observation of use of open space at different periods of time). Further discussion will be needed with regards to a new definition of design programming as meaningful and accountable for environments that support human behavior in particular physical settings. The above mentioned study cases will show that evaluation can only be conducted when considering environmental design as an "open-ended" process. (Rapoport, 2003). Future research is needed on the validity of theoretical constructs for understanding the role of the physical environment in human life from the perspective of other age groups of citizens. "