Planning matters

The UK is rich in archaeology. Across the country countless unassuming fields have unearthed precious evidence of previous human activity. From prehistoric tools, Bronze Age round barrows, Iron Age hillforts, Roman villas, Anglo-Saxon hoards, deserted medieval villages, castles, burials and so much more. While widespread, archaeology is a finite resource that can be disturbed or destroyed by building development and environmental changes. For this reason it is protected by UK legislation, national and local policy, and guidance. 

Given this level of statutory and regulatory protection it’s not surprising that archaeology can have a big impact on a commercially sensitive development site; handling it wrong can end up being rather expensive! So, what aspects of a site’s archaeology is it important to be aware of? 

Any archaeological remains within a site, both those that are already known and still unknown, will be considered to be heritage assets; either designated (assets of national or international significance) or non-designated (assets of regional or local significance). These assets are protected under the National Planning Policy Framework (NPPF) and/or the Ancient Monuments and Archaeological Areas Act 1979.

With this protection for archaeology in mind, it is important for developers to understand whether a site is likely to contain any archaeological remains - or its ‘archaeological potential’ - as early as possible. Finding out that your site contains significant archaeological remains after a masterplan has been drawn up, can result in costly amendments and delays. Likewise, having an accurate understanding of the need for archaeological surveys or excavation allows for project budgets and timescales to be drawn up with confidence.

But, when starting with an empty field or car park, many people will wonder how on earth you are meant to guess whether a site is likely to contain archaeological remains or not, let alone understand what they might be and how important they are. By its very nature, the presence of buried archaeology is usually unknown and this requires the archaeological potential of a site to be calculated, initially through the preparation of an archaeological Desk-Based Assessment (often shortened to DBA). 

This is where the importance of fully understanding the factors that influence archaeological potential is critical. The Chartered Institute for Archaeologists’ published ‘Standard and guidance for historic environment desk-based assessment’ represents the industry standard. It defines the purpose of the DBA as “an assessment of the potential for heritage assets to survive within the area of study.” This sentence highlights how integral it is that archaeological potential is judged based on an awareness of archaeological survival. The two should not be separated. But first we need to understand how each are defined.

Archaeological potential - is first assessed by considering what is known about the archaeology of the area, mainly how many and what kind of archaeological remains have been recorded within the development site and surrounding area. In other words, if your site is next to a Roman camp, the potential for archaeological remains dating from this period is likely to be high. 

Archaeological survival - considers what factors may have affected the survival of archaeological remains within the site. This includes environmental factors, such as the geological makeup of the site, the presence of water, soil acidity and any historic environmental changes, whether natural or man-made. It also considers how the historic uses and previous buildings on the site may have damaged or completely destroyed archaeological remains. 

The ultimate purpose of a DBA is to estimate the potential for archaeology to exist within a development site - quantified as very low to very high. This needs to understand what is known about archaeology in the vicinity and consider this in the light of archaeological survival on the site. For instance, the archaeological potential of a site may be calculated as very high, when based on the known archaeological context of the area alone. However, if it previously contained a building or had been subject to intensive mechanised ploughing, the chance of archaeology surviving would be reduced and the overall potential considered to be low or moderate. Likewise, the archaeological potential of a site may appear to be low, based on a lack of findings in the surrounding area, but certain environmental conditions may mean there is high potential for organic (palaeo-environmental) remains to be preserved within the site. 

To illustrate this better, a few of Lichfields’ recent project examples are described below. 

We prepared the archaeological DBA for a new educational building located on Barry Waterfront. While the report found that the coastal and inland areas of Barry have produced archaeological finds dating from the Mesolithic period onwards, our research into the changing shape of the coast and uses of the site led us to conclude that there was a very low potential for archaeology. By carrying out historic map regression and corroborating this with documentary sources, we established that the site formed part of a man-made island, created during the late-19th century construction of Barry Docks, a process which linked the mainland with Barry Island. Our desk-based research also took us further as we then turned our attention to ground investigations from a nearby site. These revealed that the made-ground extended to a depth of 16m. 

Through our careful analysis of archaeological survival, we were able to recommend that no archaeological investigations were required within the site, in turn reducing project fees and timescales significantly. 

We prepared a DBA to assess the archaeological potential of a large brownfield site in the city centre of Derby. The site is located at the southern edge of the old medieval city and archaeological remains had already been found within parts of it. Based on the recorded archaeological context alone, this would have led us to conclude there was high potential for archaeology. But when considering the factors that would have affected archaeological survival, the picture completely shifted. The site contained an existing four storey building and basement carpark, the construction of which would have destroyed any upper layers of archaeology. But it was not as straightforward as this. The site was located on a former gravel terrace of the River Derwent, meaning there was high potential for the site to contain palaeo-environmental remains, i.e. animal bones and flora/pollen. Such remains are important as they can give archaeological insights into past environments and how our ancestors interacted with them. 

Lichfields was able to advise that, other than confirming the environmental evidence, archaeological excavation was not necessary. 

Dealing inappropriately with on-site archaeology can be expensive and time-consuming. If archaeological potential is not understood early on, this can wreak havoc on project timescales and rack up hefty fees. At Lichfields we always make sure that our archaeology reports create a thorough picture of archaeological potential that is sufficiently informed by an awareness of archaeological survival. This enables us to advise on the best mitigation strategies and avoids unnecessary costs on projects, while preserving our unique heritage for generations to come. 

If you would like help determining the archaeological potential of a site please get in contact, as we would be delighted to assist.