“Toilet” is a euphemism, the fruit of a figure of speech rather than metonymy. In contemporary Western societies, this ultimate area of privacy found its name in a process of extension and social exchange. Our social need for polite and indirect expressions to designate a place dedicated to evacuation in a public context (e.g. trains, buildings and open spaces) transformed what was initially a piece of fabric into an item of furniture first, then into a room, and finally into a place filled with other things. It was only once the facility was incorporated in a room that the “petite toile” – that linen lining with laces resting on a shelf where vases, brushes and any other item required for personal hygiene were arranged – became a “toilet”. Because of this transition from a two-dimensional item into an object, then a room, and finally an environment – which often acts as a meeting place – the toilet is a formidable tool to reflect on the current circumstances of interior architecture.