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AAI – Area of Archaeological Importance
An Area of Archaeological Importance (AAI) is a rare statutory designation under Part II of the Ancient Monuments and Archaeological Areas Act 1979. It is designed to make sure archaeologists have advance warning of ground-disturbing operations in the most archaeologically sensitive historic city centres and an opportunity to investigate and record remains before they are damaged or destroyed.
There are still only five AAIs in England: the historic centres of Canterbury, Chester, Exeter, Hereford and York. Historic England’s current planning and archaeology guidance confirms that these remain the five designated areas.
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Do you need a separate AAI consent?
No. An AAI is not a separate planning-consent regime in the way that Scheduled Monument Consent is. Planning permission may still be needed in the normal way, and archaeology can plainly be a material planning consideration, but the special AAI control works mainly through an advance notice and investigation procedure.
Under sections 35 and 36 of the 1979 Act, specified operations which disturb the ground, flood land or involve tipping in an AAI generally require advance notice to the administering authority. The normal notice period is six weeks before the operations are due to begin. There are statutory exemptions, so the exact operation should always be checked rather than assuming every minor excavation is caught.
The designation can therefore matter even where the proposed work does not need planning permission. Canterbury and Chester, for example, both continue to warn owners and developers that ground works within their AAIs may require six weeks’ advance notice independently of the planning application process.
What happens during the notice period?
The advance notice gives the investigating or administering authority an opportunity to assess the archaeological implications, inspect the site and, where necessary, arrange for investigation or recording before works proceed. The purpose is not simply to stop development: it is to avoid nationally important archaeological evidence being destroyed without an opportunity to understand and record it.
For a planning application involving archaeological potential, the LPA may separately require a desk-based assessment, field evaluation or other archaeological work before it can determine the application. That is part of the normal heritage planning process and should not be confused with the Part II AAI notice procedure.
Metal detecting in an AAI
AAIs are also relevant to metal detecting. Section 42 of the 1979 Act requires consent for the use of a metal detector in a protected place, and an Area of Archaeological Importance is one of those protected places. Section 42 consent is also required to remove an object of archaeological or historical interest discovered by a metal detector in the protected place.
Check the exact boundary
The designation does not cover the whole of each city. Check the current local authority mapping and procedure before work begins. The five AAIs are:
- Canterbury
- Chester and Boughton
- Exeter
- Hereford
- York
For wider archaeological planning issues, including Historic Environment Records, archaeological assessments and non-designated archaeology, Planning Geek is preparing a dedicated archaeology and planning guide. For nationally important scheduled remains, see Scheduled Monument Consent.
Page Updated: 20th August 2026