In this paper, a theoretical framework developed in a doctoral program of research concerned with connecting philosophies of between-ness with design practice is described. The theory of ‘spatial excess’ as defined by Elizabeth Grosz is shown to be particularly useful in reconceptualising design practice. Central to this is an understanding of spatial excess in relation to anti-deterministic space, the search for different spatial inhabitations, and ephemeral people-space relations; dimensions developed further in the doctoral program through two spatial practices that exist outside conventional architecture and design – site specific installation art and experimental making. These are outlined in the paper together with findings that suggest that practices of spatial excess might be most potent in sites that are conceptually and physically interior, and that these practices should happen in everyday contexts and environments where they can be initiated by their occupants.