Archaeological Desk-Based Assessment
Archaeological desk-based assessments are a standard requirement for planning applications on sites that may contain buried heritage assets. The National Planning Policy Framework requires local authorities to assess the significance of heritage assets and to ensure that archaeological remains are properly considered before development proceeds. If your site lies within an Archaeological Priority Area or has any known heritage interest, expect your council to request one of these assessments.
Typical Cost
£300 – £5,000+
Turnaround
1 – 6 weeks
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What is a Archaeological Desk-Based Assessment?
An archaeological desk-based assessment (DBA) is a comprehensive review of all available evidence relating to the archaeological and historical interest of a site. It draws on existing records, historic maps, aerial photographs, and published sources to evaluate the likelihood that archaeological remains survive below ground and to assess their potential significance. The assessment considers the impact of the proposed development on any identified or predicted heritage assets and recommends whether further investigation, such as field evaluation, is needed.
When is a Archaeological Desk-Based Assessment required?
A DBA is required when a proposed development site falls within an Archaeological Priority Area, is located near a Scheduled Monument, contains or is adjacent to known archaeological finds recorded on the Historic Environment Record, or involves significant groundworks on previously undeveloped land. Many county and unitary authorities have archaeological advisors who will flag the requirement during pre-application discussions or at the validation stage. Sites in historic town centres, near Roman roads, or along river corridors are particularly likely to trigger a DBA requirement.
What does a Archaeological Desk-Based Assessment include?
The assessment includes a detailed review of the Historic Environment Record (HER), analysis of historic Ordnance Survey maps and tithe maps, examination of aerial photographs and LiDAR data, review of previous archaeological investigations in the vicinity, assessment of geological and topographical factors affecting survival of remains, a site walkover survey, consideration of past land use and disturbance that may have affected archaeological deposits, an evaluation of the significance of any identified heritage assets, and recommendations for mitigation including whether field evaluation is warranted.
How much does a Archaeological Desk-Based Assessment cost?
A straightforward desk-based assessment for a small residential site typically costs between £800 and £1,500. Medium-scale sites requiring detailed map regression analysis and HER searches usually fall in the range of £1,500 to £3,000. Large or archaeologically complex sites, particularly those in historic town centres or near Scheduled Monuments, can cost £3,000 to £6,000 or more. HER search fees are usually included but may be charged separately by some county councils.
Who can prepare a Archaeological Desk-Based Assessment?
Archaeological desk-based assessments should be prepared by a suitably qualified archaeologist, ideally a member of the Chartered Institute for Archaeologists (CIfA) working to their published standards. CIfA membership provides assurance that the archaeologist adheres to professional codes of conduct and technical standards. Local authority archaeological advisors may reject assessments prepared by individuals without appropriate qualifications or professional memberships.
How long does a Archaeological Desk-Based Assessment take?
A desk-based assessment for a straightforward site can typically be completed within 2 to 4 weeks, depending on the availability of HER data and the complexity of the archaeological background. Sites with extensive archaeological histories or those requiring detailed map analysis may take 4 to 6 weeks. HER searches can take up to 10 working days to be returned by the county council, which should be factored into the programme.
Frequently Asked Questions
What is a Historic Environment Record?
The Historic Environment Record (HER) is a database maintained by each county or unitary authority containing information about known archaeological sites, finds, historic buildings, and previous investigations in the area. It is the primary source of information for desk-based assessments and is maintained by specialist heritage staff. HER data is typically obtained through a formal search request, which may incur a small fee.
Will I need a field evaluation after the desk-based assessment?
Possibly. If the DBA identifies moderate or high potential for significant archaeological remains, the local authority's archaeological advisor may require a field evaluation before the planning application can be determined. This could involve trial trenching, geophysical survey, or test pitting. The DBA should clearly set out whether further fieldwork is recommended.
What is an Archaeological Priority Area?
An Archaeological Priority Area (APA) is a zone designated by the local authority where there is known or suspected archaeological interest. Development within an APA will almost always trigger a requirement for archaeological assessment. APAs are shown on local plan proposals maps and can be checked through the council's planning department or online mapping system.
Can archaeology stop my development?
In most cases, no. The planning system aims to balance development needs with heritage protection. Only nationally important remains equivalent to Scheduled Monuments are likely to prevent development entirely. For most sites, the local authority will require appropriate mitigation, such as archaeological recording during construction or a programme of excavation before works begin. This adds cost and time but rarely prevents development outright.
How does a DBA differ from an archaeological field evaluation?
A desk-based assessment uses existing records and documentary sources to predict what might survive below ground. A field evaluation involves physical investigation of the site through trial trenching, geophysical survey, or other techniques to confirm what is actually present. The DBA comes first and informs whether field evaluation is necessary.
What if archaeological remains are found during construction?
If remains are discovered during construction without prior assessment, you must stop work and notify the local authority. This can cause significant delays and expense. Having a DBA and any recommended field evaluation completed beforehand allows mitigation to be planned and conditioned, reducing the risk of unexpected discoveries causing costly stoppages.
Does the DBA cover listed buildings?
A DBA focuses on below-ground archaeological heritage rather than standing buildings. However, it will identify any listed buildings, locally listed structures, or historic buildings on or near the site and assess their setting. If works affect a listed building directly, a separate Heritage Statement or Listed Building Heritage Impact Assessment is likely to be required.
Are there areas with no archaeological interest?
Very few areas can be completely ruled out. Even sites with extensive modern disturbance may retain deeper archaeological deposits. However, sites that have been subject to deep basement construction, quarrying, or other major earthmoving are generally considered to have lower archaeological potential. The DBA will assess the degree of past disturbance and its likely effect on the survival of any remains.
Who is the local authority archaeological advisor?
Most county councils, unitary authorities, and London boroughs employ or retain an archaeological advisor (sometimes called a Historic Environment Officer or County Archaeologist) who provides specialist advice on planning applications with archaeological implications. They review DBAs and field evaluations, recommend conditions, and advise planning officers on heritage matters. Their opinion carries significant weight in planning decisions.
Can I commission the DBA before submitting my planning application?
Yes, and this is strongly recommended. Commissioning a DBA early allows you to understand the archaeological constraints on your site before finalising the design. It also means that if field evaluation is required, this can be programmed in advance rather than causing delays after the application has been submitted. Pre-application discussions with the council's archaeological advisor are also advisable.