In the context of the built environment, transformations in built form and content and in function and aesthetics can be seen as the result of architectural designers' responses to their perception of changes in societal values and institutions. This raises the question of how the general public understand and respond to the buildings that are produced and become a part of the environment of everyday experience. This paper is concerned with this question in the context of a particular building type - the single detached house - where architectural designers have produced innovative designs in response to what are perceived changes in life styles, perceptions of the environment and new technologies. Our approach is to contrast aspects of experience which result from exposure to architect designed houses with the same experiences of everyday and traditional house forms. In choosing what aspects of experience to study we have been guided by a model of how past experience is represented in mental models or knowledge structures and the role these play in ongoing experience of particular examples of environmental types. Existing cognitive representations of frequently experienced environments result from ongoing, long term exposure to and interaction with these environments. This type of extensive, repeated experience results in a non-conscious form of learning (Lewicki, Hill and Bizot, 1988) which leads to a representation of the regularities in the environment. In the context of interest in this paper, there are regularities in the particular sets of physical attributes and relationships between attributes which have typical ranges of values associated with them which are characteristic of houses. Our knowledge structures mirror these typical ranges of values for the physical attributes and relationships (for a more complete discussion of knowledge structures in general see Mandler, 1984 or, in the context of the built environment, Purcell, 1986). This knowledge about the world is however relatively abstract or generic as it represents the typical regularities present in the world. Ongoing experience, formed by the interaction between the characteristics of a particular example and generic knowledge creates a second type of mental representation. This consists of a representation of the differences between the characteristics of the instance and the existing generic knowledge (Purcell, 1992). This difference creates the relative uniqueness of the experience associated with a particular instance. Further it provides a mechanism for the more or less accurate recognition and recall of previous encounters with particular examples and the types of experience associated with those encounters - an aspect of experience which forms one major focus of this paper. An innovative or new example of a type, such as an architect designed house will be experienced on the basis of what attributes, relationships and ranges of values are present in the example and how they relate to existing generic and specific cognitive representations. To the extent that the new house represents a metamorphosis, that is an example of a house that is different to existing generic knowledge, it will be experienced as atypical and unfamiliar even though it will be recognised as an example of the type. These differences between an example and existing knowledge however also form the basis for other types of experience which can be regarded as accompanying the experience of familiarity and typicality. Discrepancy or difference to existing cognitive representations establishes the conditions for affective experience (see Gayer and Mandler. 1987, Purcell.