A desk-based assessment is usually requested where a development site sits in an area of known or suspected archaeological interest. That can include town centres, village cores, former settlement edges, land near scheduled monuments, historic farmsteads and plots with evidence from previous discoveries nearby. In practice, the requirement often appears because the local planning authority needs a clearer picture of archaeological risk before deciding the application.
The site types most likely to trigger a DBA
Although every local authority has its own validation process, some situations repeatedly lead to requests for desk-based assessment work.
- Sites inside areas identified as archaeologically sensitive on local records or planning constraints maps.
- Land within or near historic settlement cores where earlier occupation may survive below current ground level.
- Development close to scheduled monuments or areas with known prehistoric, Roman, medieval or post-medieval activity.
- Large greenfield or rural sites where the absence of modern development does not mean the absence of buried archaeology.
Why the requirement appears at application stage
Planning officers and archaeological advisers need enough information to understand whether the proposal could affect heritage assets below ground.
- Without a DBA, the authority may not be able to judge the site’s archaeological potential with confidence.
- The assessment provides baseline evidence that helps shape conditions, further evaluation requests or mitigation strategies.
- It can also demonstrate that the applicant has considered historic environment issues proactively rather than waiting for a problem to emerge later.
- Where archaeological sensitivity is lower than feared, the DBA may help avoid unnecessary escalation.
How to know early whether one may be needed
The best time to ask the question is before the application is assembled, not after a validation query lands.
- Review the site’s planning context early and check whether the local authority highlights archaeological constraints in the area.
- Consider the age and historic character of nearby settlement, roads, churches, field systems or known findspots.
- Seek professional advice if the site lies in Somerset, North Somerset, Bath and North East Somerset or another historic part of the South West.
- Treat a DBA as an early planning tool rather than a late compliance task.
Frequently asked questions
Can a house extension require a desk-based assessment?
Sometimes, yes, if the site lies in a highly sensitive archaeological area or the groundworks are significant enough to raise concern.
Does being outside a conservation area mean a DBA will not be needed?
No. Archaeological sensitivity and conservation area status are different issues. Buried heritage can exist well beyond designated built heritage areas.
If a DBA is required, will excavation automatically follow?
Not automatically. Some projects stop at the desk-based stage, while others lead to evaluation or mitigation depending on the findings.
Need advice on this type of project?
If you are unsure whether your planning proposal may need an archaeological desk-based assessment, AS Archaeology & Heritage Services can review the site context and advise on the likely next step.
Related links: Desk-Based Assessments | Contact AS Archaeology | Reports