These categories are derived from the philosopher Michel de Certeau and define two spatial arenas.
Spatial practices are the acts, routines, rituals, actions, movements, and uses that are carried out by people in their daily lives. This is meant to go beyond the idea of considering people as ‘users’ – the anonymous, neutral, blank people that are imagined to live in architectural proposals. Spatial practices go beyond function and use, and as such must include social and cultural identity. For example, rather than limit a kitchen to ‘cooking’ and a functional analysis of abstract movements required to make a meal, spatial practices taken into account what kind of meals might be made, by whom, and how often, among other aspects. But even more significantly, understanding the spatial practices of a kitchen means knowing that a kitchen is used for socialising (it’s where everybody hangs out during parties), eating, snacking, conversing, making telephone calls, exchanging information (via post-it notes on the fridge), and so on. The key aspect of all of this is to remember that these practices are spatial – they occur in space in a particular way and get some of their meaning from being spatialised.
Spatial form is both the physical and material solid-stuff of the built environment and its void-space. It is meant to capture the relationship between solid form and void-form as well as considering space as continuous and therefore linked to the broader context surrounding your project’s site. This term is meant to join two separated physical aspects of designed things – you may find that some refer only to form, while others only to space, each either downplaying or ignoring the other term.
From de Certeau we also understand that, contrary to many architectural approaches, spatial form and spatial practices mutually create and define each other. Again, there is a split between those who see architecture as being about its physical aspects almost exclusively (ignoring spatial practices) and those who see it as experiential (ignoring spatial form). While each term on its own enriches the more commonly used but reductive concepts (form and use), they are most useful when considered together and inseparable.
Source: Michel de Certeau, The Practice of Everyday Life. The above is not a direct or literal translation of de Certeau’s concepts but rather a summary of my adptation of his ideas as developed in my research and practice.