Archaeological deposits pose a financial risk for developers resulting from the planning constraints that are imposed by the premise that a public interest exists in those deposits and in the consequent impact that any development might have upon them. In England and Wales, those planning constraints arise from the principles now established by the National Planning Policy Framework. Here archaeological deposits are identified as being among the heritage assets that go to make up the heritage environment, and developers are required to execute works that are environmentally sustainable. My aim in this short piece is to consider what might be required of policies of heritage sustainability.

My dictionary defines an asset as ‘anything valuable or useful’, two qualities that, I assume, may lie dormant in the ‘thing’ until they are realised by means of some form of engagement (value through the market and usefulness through deployment, for example). It would seem to follow that a policy of sustainable development, when applied to the heritage environment, requires that the potential value or usefulness of its assets should at least be maintained. Does this simply require the physical preservation of those assets? Not necessarily, for perhaps the potential value and usefulness of one heritage asset might be transferred into another that takes another form. I assume that this thinking is what lay behind the not terribly successful policy of ‘preservation by record’. There are obvious problems that attend the strategy more widely in the heritage sector. For example, the value of a long standing building at the heart of a community which is commonly treated as a point of reference and part of an aesthetically pleasing vista is not easily transferable. However, it does seem that the heritage asset of many such buildings is often assumed to be embodied in their facades where value is revealed in the look of the thing, and this has resulted in the preservation of the facade whilst the rest of the structure has been sacrificed. We should note, however, that stone circles, castles, churches, and country houses (among others) cannot be reasonably treated in a similar way for the simple reason that their value is realised by occupying, exploring, and using their interiors. The ways the value and usefulness of a heritage asset might be realised must therefore guide our understanding of how that asset can be sustained.

The problem of establishing what constitutes sustainability in archaeological deposits arises partly from the assumption that the potential value of any deposit is almost entirely described by the nature of its preservation (desiccated and eroded, or waterlogged and deeply buried) and where the realised value is contingent upon the methodological skills of recovery and analysis. From this perspective, the risks to the developer amount to the costs of applying the latter (competent methods) to the former (nature of deposits). Costing in this way might appear attractive in its directness, although in practice the scale of the unknowns (what the deposits might actually contain) maintain a higher level of risk than either the developer or contracting archaeologist are likely to find comfortable. Carver’s discussion of the Crossrail project explores where the responsibilities lie in managing those risks. The problem, however, remains: are we clear as to the ways that the process of excavation realises the utility and value of the deposits and that it delivers sustainable development?

Let us begin with what might constitute the utility and the value of an archaeological asset. Perhaps its utility is that it allows us to engage with the now fragmentary conditions of past human experiences and to investigate, and indeed debate, the conditions and forces that operated in a past of which that human presence was obviously a part. Any claim that our procedures are environmentally sustainable should mean that the utility of the asset in facilitating such an enquiry is itself sustained. This ability to bring certain aspects of the past into view and to open them to investigation lies not in the material itself, however well preserved that may be, but in the perspectives established by the procedures of investigation. And this is where the value of the asset is realised, for value here is not that of commercial return but rather what we gain from considering the perspectives that best confront the diversity and scale of human history. We learn and see the world afresh. This is a value fashioned by method and critical thought: it is experienced through the practical exploration of surviving conditions? and it is a value that must be sustained if our heritage policies deliver what they claim.

However abstract all this might sound, it is in fact blindingly simple, although admittedly it requires an inversion in current reasoning. Do not start from the assumption that humans make their environment, but rather that the environment makes certain kinds of humanity possible. It does this by providing or restricting access to resources, making or hindering the possibility of certain kinds of perception, restricting access to spaces for some, and opening access to others. In other words, the best way to think about the cultural environment is not from the perspective of its making (as something imposed on the landscape) but from the perspective of the ways that environment could be read by learning to live in an architecture of things and to gain, or to be restricted, access to certain resources (be those resources food, security, political authority, spiritual revelation, or whatever). In this way, people became distributed across a spatial architecture that defined them.

The effectiveness of this approach was demonstrated in the excavation programme at Heathrow Airport Terminal 5 (Andrews, Barrett and Lewis 2000), where the excavators were asked to realise an understanding of how the changing forms of the landscape made possible different paths of movement and traditions of occupancy and, on this basis, the ways in which the landscape was strategically modified and the consequences of that modification for future inhabitation.

In the case of most urban landscapes, the archaeological engagement with archaeological deposits is quite unlike that encountered in the large-scale open excavation possible at Heathrow. Urban excavations are often restricted spatially by interventions into deep deposits, where the kind of cost estimates and management procedures sketched above are likely to apply. In the example of Crossrail, the procedures for managing the risks for the developer of this massive infrastructure project across London have clearly been exemplary. However, what more is required of urban excavations if they are to contribute to environmental sustainability?

To demand that the archaeology of the urban environment makes the human history of occupying that environment visible does not mean that we simply expose the ancient fabric of a city. We are all familiar enough with the sad spectacle of chunks of ancient masonry marooned and ignored in a busy thoroughfare. History is not, after all, a matter of events, ancient relics, and the actions of ‘great’ people: these are merely the objects of antiquarian curiosity. History concerns the processes that shape the human world, the changing material configurations that have brought together the flows of human energy, technologies, raw materials and the rest of nature to sustain these places as particular environments of human existence. As I have attempted to argue, archaeological assets are useful and achieve their value in these terms: they allow us to understand how those conditions once operated, their consequences in people’s lives and their resilience and fragility, as well as how they came into being and passed away. I suggest, therefore, that archaeological assets can be maintained (i.e., can be rendered sustainable) by transferring the value of deposits excavated into a mosaic of resources that describe the changing conditions that shaped those earlier human environments and have, by dint of developer investment, been made accessible to people who might find that they enrich their experience of living and working in those locations.

Four points follow. First, it is the archaeologist’s, and not the developer’s, skill and responsibility to deliver sustainability of value and usefulness by transferring the asset represented by deposits excavated into a new medium. Second, history is contentious. The fact that Guy Fawkes was baptised in the late medieval church of St Michael le Belfrey that stands alongside the Minster in York (although differently aligned on the more ancient axis of Petergate) is perhaps of passing interest. That this opens a window onto the history of recusant Catholicism in Yorkshire and the wider struggle of the reformation in Europe has implications for an understanding of the surviving fabric of that city, and provides the richer potential of a journey of historical enquiry. Third, the urban landscape comprises a series of geographically contested and overlapping spaces extending across wealth and poverty, authority (with its own conflicts between, for example, church, state, and market), and rebellion. How these spaces were appropriated, defined, and defended is part of a historical narrative that has not remained buried beneath the streets but, courtesy of archaeology, can now accompany the contemporary experience of urban life: history may be performed simply by reoccupying the shadows of these earlier spaces. Finally, digital media have the potential of revolutionising the ways the assets of the urban heritage environment may be stored and accessed. The conflicting narratives that have defined a place over time, the source materials available for further investigation, and the challenges that future thought and investigations might address will all surely become increasingly open to digital investigation from within those places. Enabling us to explore the ways that historical processes were located within the resources of time and place could therefore be offered by means of digital information that has been built, as a sustainable heritage asset, into the fabric of the contemporary urban environment.