Archaeological areas in Surrey

County Sites of Archaeological Importance and Areas of High Archaeological Potential

Surrey's County Sites of Archaeological Importance (CSAIs) and Areas of High Archaeological Potential (AHAPs) form an archaeological alert mapping system. These areas are used by members of the Historic Environment Planning Team to provide archaeological advice and recommendations on planning applications across Surrey's 12 individual planning authorities.

National Planning Policy requires planning authorities to consider 'non-designated Heritage Assets' in deciding an application. All archaeological remains can be considered to fall under this definition. Therefore we have adopted CSAI and AHAP areas to identify known or potential archaeology which is likely to require additional planning consideration.

In addition to these mapped areas, all development sites over 0.4 hectare (approximately 1 acre) are also assumed to have a potential to contain undiscovered 'non-designated heritage assets'. The use of these two policies aims to give planners, landowners and the general public more clarity about how national policy is implemented at a local level.

What does it mean if a County Site of Archaeological Importance (CSAI) or Area of High Archaeological Potential (AHAP) is located on your land?

The areas are simply a planning tool so there are no accompanying rights or restrictions. The presence of an AHAP does not mean that the land cannot be developed. In the event that you wish to submit a planning application for land within (or partially within) one of these areas, this would trigger consultation with the Historic Environment Planning Team, due to the potential impact on a heritage asset – see below.

Where a CSAI is present, it is advised to check whether the heritage asset is also a nationally designated Scheduled Monument as these will have further levels of legal protection due to their national importance.

What does it mean if there is a County Site of Archaeological Importance (CSAI) or Area of High Archaeological Potential (AHAP) within your planning application area?

All planning applications within one of these areas will trigger consultation with the Surrey Historic Environment Planning Team. Normally an Archaeological Desk Based Assessment will be required to be submitted with any planning application associated with one of these areas to help determine the potential archaeological significance, and likely impact of the proposals.

The outcome will vary depending on the specifics of the site and application; in some cases a programme of mitigation work will be designed, in others further on site evaluation work will be necessary in order to reach a decision, or there may be no further archaeological concerns. Any planning requirements will be proportional to the proposal and the potential significance of the heritage asset.

If you are thinking of submitting a planning application and wish to discuss the likely archaeological requirements, please feel free to get in touch using the contact details below.

Making changes to a County Site of Archaeological Importance (CSAI) or Area of High Archaeological Potential (AHAP)

The CSAI and AHAP areas are reviewed every 5 years, however alterations can be made in exceptional circumstances. The most recent review was completed in 2023, and the next round of review is due to take place in 2028.

The areas are identified in accordance with a set methodology and linked to information contained within the Surrey Historic Environment Record database and published sources. If you have further information regarding an identified, or potential new, CSAI or AHAP the team would be pleased to keep this on file to inform the next review process. Please use the contact details below to get in touch.

Please be aware that all new information will be considered within the approved assessment process in accordance with the set guidelines. Please see our Archaeological Areas Selection Criteria (PDF), for more information.

How do you find out more about the Archaeological Alert Mapping in Surrey?

The CSAI and AHAP area data can be viewed on our interactive map. This can be found by turning on the respective layers in the 'Heritage' section of the layer list.

For further information on individual areas please contact us using the contact details below.

Contact us

For further information regarding individual Archaeological Areas, or to discuss possible archaeological planning matters, please email:

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