Resumen: Ephemeral architecture has been linked to assembling and dismantling procedures of exhibition halls and exhibition facilities, whose legacy remains in many cases reduced to photographic sequences or models. This work proposes to extend the concept of the ephemeral from such idea of provisional construction towards a long-lasting architecture but with a form that is visually evanescent. A more symbolic aspect, involving visual perception and sensory experience. Thus, the representation of the ephemeral on the facades has resulted in the use of superimposed reticulated wefts, translucent planes, reflective surfaces and, especially, the extensive use of glass, no longer as a transparent closure but as a plane of image reception. In the Cartier Foundation (Nouvel, 1994) and the Sendai Media Library (Ito, 2000), the facade appears endowed with a new aesthetic quality. The relative transparency constituted by a set of reflected images, lights and glitters, silhouettes, shadows and backlit figures, expresses visual qualities associated with the ephemeral: fleetingness, change and transience.