Archaeological remains can survive anywhere and everywhere, often unseen and unsuspected. From fields and villages to towns and cities, archaeology is all around us and shapes our surroundings.

It poses both risks and opportunities for all developments, whether in urban or greenfield locations. There are approximately 34,000 Scheduled monuments in the UK but despite this being a big number, most archaeology that housing schemes affect are non-designated heritage assets. While, as non-designated heritage assets, archaeology is not usually an absolute design constraint, it can present serious design, planning and implementation issues to any development scheme. Due to their land take, this is a risk for major residential schemes.

Early Project Planning

If tackled early enough in project planning, most of the challenges archaeology poses, apart from the cost, can be overcome fairly easily. It is when archaeology has not been considered early enough in the development process that things can go wrong with unexpected costs and delays in critical areas. The earlier the archaeological risks can be considered and evaluated, the less likely that archaeological remains become a challenge to development.

Questions to be asked

The earlier the better is the mantra when considering archaeological and heritage matters in the development process. Questions need asking such as – is there anything known archaeology here already? What is known in the wider area and does that have any implications for our site? Is the geology and topography a factor influencing the potential for archaeology? Is there evidence for subtle earthworks not even visible to the eye and what about cropmark evidence? Other questions are also at play, such as, what is the usual approach of the LPA’s archaeological advisors in relation to geophysical survey, trenching sample sizes and predetermination v conditional trenching?

These questions can start to be answered through initial high level appraisal which informs the development’s risks register, its constraints and opportunities assessment and early masterplanning & cost planning.

Assessment & Evaluation

As a proposed residential scheme starts to progress through the Local Plan, outline application and RMA process, the initial high-level assessment gets refined, tested and developed through detailed research, non-intrusive and intrusive archaeological investigation. Such work typically involves desk-based assessment, heritage statement, geophysical survey and/or trenching.

The thorny issue of evaluation trenching, its sample size and whether it is pre-determination or conditional, is almost inevitably going to raise its head at some stage. Although the NPPF does have provision for evaluation trenching, it does not provide guidance on when in the planning process this should happen. Many LPA archaeology advisors now routinely require pre-determination on all green field development sites, but others take a more flexible and (dare we say it) pragmatic approach. There are, of course, many sites where archaeology has been established to be a very serious issue that it is in the developer’s/land promoter’s interest to undertake trenching pre-determination. There is no one size fits all model, unfortunately.

Mitigation Works

In some instances, the archaeological evaluation identifies archaeological remains of significance which require archaeological mitigation works which typically takes the form of excavation (sometimes referred to as strip, map and record), although a watching brief during construction works may sometimes be appropriate.

Once all fieldwork has been completed, construction works can generally commence whilst the archaeological post-excavation assessment, archiving and publication work is in progress. Occasionally archaeological remains are identified which are deemed worthy of preservation in situ which can require changes to the of development layout, which is why understanding the archaeological implications across sites at an early stage is key.

How can Orion assist?

Orion’s skilled archaeology team is experienced in advising landowners, developers and their agents on all aspects of potential and actual archaeological matters. Providing pragmatic support from the start of a project with land disposal or acquisition, right through to planning and the discharge of archaeological planning conditions.

As a CIfA Registered Organisation & accredited CIfA members, we problem solve with our clients in a timely and cost-effective manner. Our mix of specialist expertise and commercial understanding means we can be relied upon to deliver honest and accurate advice, negotiate favourable outcomes with statutory bodies, and establish and manage archaeological fieldwork.

Case Studies

The following case studies demonstrate Orion Heritage’s pragmatic & expert approach to sites where archaeological remains had the potential to become a challenge in advance of major residential development.

South Marston, Swindon

Clients: Hallam Land Management, Taylor Wimpey, Vistry & Hannick Homes

South Marston is a major, consented residential scheme for 2,380 homes, community facilities, a new primary school, and green space. Orion was appointed to undertake a heritage assessment and the heritage ES chapter for the outline planning application and then the discharge of the archaeological conditions on the outline consent.

Orion undertook a desk-based assessment, geophysical survey, and several phases of archaeological evaluations which identified multiple historic settlements and features, including Bronze Age, Iron Age and Roman. On our expert advice, the scheme layout was devised to exclude most of the large historic settlement to reduce both the potential impact on the remains and the cost of excavation. Our assessment also showed that there would be no effects on nearby listed buildings.

Orion formulated and agreed a site-wide outline archaeological mitigation strategy, which was written into the archaeological planning conditions. After planning permission was granted, we devised and agreed a thorough site-wide Written Scheme of Investigation and an outline archaeological management plan for the archaeological remains to be preserved in the open space of the scheme.

We continue to work with Taylor Wimpey & Vistry to run the large scale archaeological mitigation excavations required ahead of construction of this major residential scheme.

Land at Spa Road, Melksham

Clients: Hallam Land Management, Bloor Homes & Barratt David Wilson Homes

This is a consented scheme for 450 dwellings with land for medical or communal facilities and a relief road. Outline permission was granted in 2016 with a condition requiring mitigation investigations.

A member of Orion’s management team undertook an archaeological desk based assessment, organised & managed a geophysical survey of the site and managed pre-determination evaluation trenching while in previous employment. The geophysical survey revealed a focus of undated enclosures within part of the site. The evaluation trenching revealed that these enclosures were of Roman date with some slight evidence for a possible stone structure or stone surfaces. This was interpreted as being a small rural settlement typical of large parts of Wiltshire.

Following the granting of outline planning permission, Orion Heritage were appointed to agree the scope of mitigation excavation works on the area of Roman remains and manage the fieldwork and post-excavation works. The excavations revealed the remains of a Roman villa with a rudimentary underfloor heating system in parts of it. The building had been largely removed and only the traces of the foundations survived. An associated stone lined well was revealed which was approximately 2m in diameter and 5.5m deep dating to the 3rd & 4th centuries AD. Finds from the well included structural timbers, wooden stakes, a wicker basket, leather shoes, a large quantity of animal skulls and whole pots. The villa overlay a series of field systems within which were potential roundhouses which were the forerunners of occupation prior to the villa.

Despite the unexpected find of the villa and its well, the works were delivered on time well ahead of construction commencing. The well required a variation to the budget as this feature could not have been anticipated based on the results of the evaluation and geophysical survey.

Kingsbrook, Aylesbury

Client: Barratt David Wilson Homes North Thames

Kingsbrook is another major consented residential scheme for 2,450 homes, 10ha of employment uses, neighbourhood centre, 2 primary schools, eastern link road, green infrastructure, community facilities and flood defences. Following the granting of outline permission, Orion was appointed by BDW to progress the archaeological mitigation works required by the conditions of the outline consent.

Some pre-determination works had previously been undertaken comprising a geophysical survey of the whole site followed by some very limited and targeted trenching. In consultation with Buckinghamshire Council and the client, Orion agreed a site-wide mitigation strategy comprising evaluation trenching on a development phase by phase basis and mitigation excavation of 6 areas across the site. These investigations revealed late Iron Age/early Roman settlement and field systems as well as two associated cremation cemeteries and some limited Saxon activity. These works were completed within budget and within the timetable required, despite challenges posed by the Covid pandemic and wet ground conditions from inclement weather conditions.

Exeter University Department of Archaeology & History and the Institute of Heritage Sciences and the Spanish National Research Council in Spain have recently published a ground breaking Lidar based study on the Roman road network of Devon & Cornwall.

Prior to this study, the understanding of the Roman road network in the SW had barely changed since Ivan Margary’s 1967 publication ‘Roman Roads in Britain’ in which he concluded that Exeter was the focus of the road network in South West England. Exeter University’s study has established that instead of Exeter, it was actually North Tawton that was the centre of the road network which radiated out to the tidal estuaries on the north and south coasts of Devon and down into Cornwall.

As well as identifying the key role of North Tawton in the network, utilising Lidar data analysis, the University team have identified an additional 60-70 miles of additional Roman roads to the west of Exeter where very few had previously been recorded, and using predictive modelling, they have identified further possible routes of previously unsuspected Roman roads. This study will radically change the understanding of the South West in the late prehistoric and Roman period. As the report on the study states:

“…further lengths of road are yet to be identified on the ground. Although it could be argued that roads no longer in use and visible as earthworks might be of pre-Roman, or medieval date, the combination of 1) the consistency in construction practice (agger, quarry pits, terracing), 2) the coherency of the road pattern, and 3) in places the stratigraphic relationship with medieval field systems, argues for it being of Roman origin. The network presented here is only that which has been mapped as an archaeological earthwork visible on LiDAR data and, for example, there are gaps between those segments connected by historic tracks, lanes and roads which are likely to have fossilised the Roman route.”

Fitting into these exciting results is the recent discovery of a section of a previously unrecorded and unsuspected Roman road at the proposed business park that forms part of the Sherford new town just to the east of Plymouth. The extensive programme of detailed archaeological investigations that are being undertaken ahead of the construction of the Sherford new town just to the east of Plymouth, has recently discovered a section of a previously unsuspected Roman road. This section of the road which extends across the length of the area towards Plympton demonstrated the construction methods with its crushed slate surface and adjacent drainage points still clearly visible and well-preserved (

At the time of excavation, the road was undated but due to the way it was constructed was thought to be Roman in date. Optically stimulated luminescence (OSL) dating of the soil immediately below the road surface provided a later Iron Age date (300-130BC) date. As these soils pre-date the construction of the road, this dating has been interpreted as being reasonable evidence for the road being of Roman date and probably at the earlier end of the occupation range.

The section of the Roman road excavated at the Business Park is 1.7km to the west of the position of the Roman road in the area predicted by the Exeter University study. The University study predicted that the road would be orientated north-south but the Business Park road is orientated north west -south east. The different orientation could be that the model’s predicted route is slightly incorrect or that the road excavated at the Business Park is a previously unsuspected spur off the route identified by the University’s modelling. Whichever explanation is correct, the Sherford Business park excavations have confirmed that the predictive modelling by Exeter University appears to be reasonably accurate and, at least in the Plymouth area, definitely closer enough to inform the research questions of future archaeological investigations relating to the Roman occupation and use of the area.

Rob Bourn, Managing Director of Orion Heritage said,

“Enhancing our understanding of not just Devon, but also Britain’s ancient history, the archaeological work at Sherford continues to be fascinating. We are thrilled to work on these important historic investigations, and hope the findings at Sherford help to encourage everyone to take an interest in local history and the secrets under the soil.”

Orion Heritage has been managing the extensive archaeological investigations that are happening ahead of the construction of the new town on behalf of the Sherford Consortium (Vistry Group and Taylor Wimpey).

Reserved matters permission was sought by Rydon Homes for 26 new homes on land off High Street, Barcombe Cross in Lewes District.

The application was refused on the grounds of the effect of the proposed scheme on the character and appearance of the area. While the reason for refusal was not specifically related to built heritage issues, the site is surrounded on three sides by the Barcombe Cross Conservation Area and so the effect on the character of the conservation area was a significant element of this refusal. The scheme had been allocated in the Lewes District Local plan and outline planning permission for 26 homes had been granted. The scheme was recommended for approval in the committee report but was refused by the Planning Committee.

The primary heritage issue was the effect on the character of the Conservation Area. It was accepted by all parties that the development would have a less than substantial harmful effect on the conservation area but this had been considered to be acceptable, subject to the high quality design of the scheme, when the site was allocated and granted outline consent. The proposed reserved matters scheme was designed in close consultation with the LPA’s planning case officer, Senior Conservation Officer and Landscape officers so as to ensure that the reserved matters scheme was to fit in with the character of the conservation area.

The Inspector concluded that the design of the proposed dwellings would reflect the built heritage and local vernacular which characterise Barcombe Cross. It was accepted that there would be no harm caused to the special interest of the Conservation Area, other than that caused by the loss of an undeveloped field within the setting of the conservation area, as identified as part of the assessment of the outline scheme. He also concluded that the appeal scheme would be respectful of the character, appearance and setting of the Conservation Area, as per the requirements of the local plan policy for the allocation.

Orion Heritage did the archaeological assessment, evaluation trenching and heritage statement for the outline scheme and was the heritage expert witness at the appeal.

Orion’s MD Rob Bourn was the heritage expert witness and the barrister was Richard Turney KC. The archaeological assessment was done by Charlie Willis, Sylvia Lock managed the evaluation trenching and Jan Mathieson and Robin Sheehan did the heritage statement and additional assessment of the Barcombe Cross Conservation Area.