In the UK, the uncodified status of the Interior affords it an expedient critical substance, propagating a culture and a knowledge base that is expansive and one that is essentially fluid. In other words the definition and cultures of practice, research and education in the subject are yet to be unequivocally consolidated and explicitly systematized. In this short essay I will describe this condition as ‘Unfixed’. Hildebrandt captures the essence of the unfixedness of Interior Architecture in the essay The Gaps Between Interior Design and Architecture. Cited at the start of this essay, he suggests that meaning in Interior Architecture is embedded inside, as well as outside, of the building. In doing so he corroborates the notion that the subject as one that is engrained within the architectural matter, appearing to be part of an established condition. Yet it is as reliant on what lies outside the building as much as that, which is rooted within it. Perhaps inadvertently, Hildebrandt supports the notion that in any description of meaning in the subject the ambiguous qualities of Interior Architecture are still forcefully prevalent. The suggestion of capturing meaning within as well as outside the building, in order to offer a broad context from which to derive the substance of Interior Architecture, offers a limitless context from which to derive the meaning of the subject. On this basis the complexities of Interior Architecture, its uncodified yet embedded condition in the matter of the building, affords it the opportunity to continually redefine and experiment with its own meanings and processes of origination. This situation always offers the opportunity to reiterate and redefine its fundamental and essential cultures of practice, research and education, a process that incorporates an analysis of its relevance to the design and construction of the contemporary built environment.