One of the problems that haunts any discussion of tectonics in architecture (typically defined as the raising of construction to an art form) is that it can often seem like an obvious fallacy is being committed, broadly of the pars pro toto variety. If we become too fixated on the fabric of the building as the very ‘raw material’ of architecture, then it can soon seem – as David Leatherbarrow once claimed in a conference on this very subject – that tectonics is a ‘very small glass into which we are trying to pour an awful lot of wine..’. 
Leatherbarrow may indeed be right, especially if we consider (as the standard definition above suggests) that tectonics simply aims at some kind of rapprochement between technology and aesthetics. In which case, it clearly only addresses the second and third of the famous Vitruvian triad of architectural characteristics: ‘firmness’ and ‘delight’, while ignoring the equally important quality of functionality or ‘commodity’. If this is in fact the case, then tectonic expression could easily be dismissed as an optional extra, something added on to an otherwise already technically adequate architectural solution. If constructional richness and articulation is thus seen as a luxury – the province of high-end, or boutique, projects for wealthy private clients – then where does that leave the majority of what we might call ‘everyday architecture’? Is there another role for tectonic expression, beyond the pleasures of working with expensive materials or the uncertainties of traditional craftsmanship?
I would like to suggest that tectonics does indeed have a broader relevance in architecture, beyond the particular attractions of ‘aestheticized technology’, whether we prefer a stripped-back, bare-bones Brutalism, or the current digital revival of surface ornamentation, with its connotations of playfulness and excess. If we think instead of a kind of ‘meta tectonics’ – or what I prefer to call a tectonic sensibility – then we might also be able to draw some broader lessons from those inherent qualities and natural tendencies of materials and systems that tectonic expression sets out to celebrate. I am thinking here of a deeper sensitivity towards what Lars Spuybroek has called The Sympathy of Things , an intuitive, bodily ‘feel’ for the constraints and possibilities of tectonic elements, which arises from the embodied experience of working directly with materials. My suggestion is that this idea might also be transferable into the realm of architecture’s spatial and functional possibilities, offering a way of incorporating that missing Vitruvian term, commodity, within a new and broader definition of tectonic architecture.
This may at first seem like a strange reorientation of tectonic thinking, into what would normally be considered an immaterial realm. But, I would argue that this is precisely what emerges from thinking about a building (as philosophers of technology like Bruno Latour and others typically do), less as a fixed object and more as a set of tools: spaces that offer the user a structured field of possibilities for action. What I am suggesting is that spatial and functional organisation have a materiality all of their own.
I take this idea from the work of two key historical figures, the American psychologist James J. Gibson (1904-79), and the French phenomenologist Maurice Merleau-Ponty (1908-61). Gibson developed his ‘theory of affordances’  to describe those opportunities offered to a living organism by the various features of its surrounding environment. In the case of buildings, the most obvious examples would be things like windows, doorways and staircases, features that either afford views or bodily movement between what would otherwise be disconnected spaces. Other technologies, like tools or even musical instruments, also remind us that these affordances vary according to the bodily abilities of the individual to exploit them. For example, a skilled craftsman with a feel for the natural characteristics or grain of a material can adapt a process dynamically to suit the opportunities emerging as the work develops.
Likewise, Gibson suggested that our perception of the environment is grounded in a sense of its possibilities for bodily interaction, an idea that also echoes an earlier analysis in Merleau-Ponty’s major text Phenomenology of Perception. For Merleau-Ponty, perception begins with what he variously named ‘motor intentionality’ or ‘motor cognition’, meaning a primary bodily reaction to what he called the solicitations of the world around us. As built spaces offer affordances for particular kinds of behaviour, for Merleau-Ponty language could also be said to offer affordances for activities such as rational thinking and communication. Most importantly for Merleau-Ponty, language is not simply a tool for ‘representing’ pre-conceived ideas, rather it acts as a mechanism for constituting thoughts as such. As he wrote in a memorable line from his late essay ‘On the Phenomenology of Language’: “My spoken words surprise me myself and teach me my thought.”  The same sense of discovery and creativity inherent in all material practices is also highlighted by Bruno Latour in his notion of “the slight surprise of action”  which he develops as a critique of the assumption of mastery inherent in the conventional definition of top-down design.
So, the tectonic sensibility as suggested above involves thinking of functional possibilities as affordances for action, but always within the relational framework set out in Gibson’s work. Rather than rigidly imposing programmatic functions in a top-down deterministic manner, spaces could instead offer more loosely structured fields for creative appropriation by the building user. Features designed for one purpose can then also be turned to other uses, as Merleau-Ponty suggested in the case of language: words are – often unwittingly – ‘coherently deformed’ to invoke and express new layers of meaning.  By extending this sensitivity to material affordances into the realm of spatial and conceptual configurations, it could be argued that ‘tectonic architecture’ is after all, simply architecture as such.
 Q & A discussion at the international symposium Towards an Ecology of Tectonics, Royal Danish Academy of Fine Arts (KADK), Copenhagen, Nov 1, 2012.
 Lars Spuybroek, The Sympathy of Things: Ruskin and the Ecology of Design, London: Bloomsbury Academic, 2016.
 James J. Gibson, The Ecological Approach to Visual Perception, Hillsdale NJ: Lawrence Erlbaum Associates, 1986, pp127-143.
 Maurice Merleau-Ponty, “On the Phenomenology of Language”, in Signs, translated by Richard C. McCleary, Evanston IL: Northwestern University Press, 1964, p88.
 Bruno Latour, Pandora’s Hope: Essays on the Reality of Science Studies, Cambridge MA: Harvard University Press, 1999, pp280-283.
 Merleau-Ponty, op. cit. p91.
These ideas are also discussed in more detail in my recently published book Merleau-Ponty for Architects (Routledge 2017), and further developed in discussions with Michael Hensel, Anne Beim and Marie Frier Hvejsel, at KADK Copenhagen (November 2016).