This article contributes to the growing body of literature on organisational spaces by taking a communication-centred approach to organising that stresses a performative view of communication as constitutive of organisation. Based on this constitutive premise, I propose to study the ‘spatial grammar of organising’, which implies (a) describing the spatial imaginary of an organisation: the spatial images that are voiced and embodied, and their effects on the production of organisational spaces; and (b) attending to the processes through which these organisational spaces are performed and to their implications. Applying these analytical steps in the study of an outreach organisation's development strategy, the article shows that the constitution of organisational spaces is a communicative process of boundary setting in which actors of various ontologies are related. Hence, the spatial imaginary of an organisation is not abstract and neutral: it has concrete organisational and political effects in defining the organisation's space of action.