The Thames Basin Heaths SPA covers an area of 8274.72ha across Hampshire, Berkshire and Surrey. It forms part of a complex of heathlands in Southern England, which support important breeding bird populations, including the Dartford Warbler, Nightjar and Woodlark.

More general information on Special Protection Areas (SPA) is available from Natural England.

The SPA affects most of Farnham

About 80ha of the Thames Basin Heaths SPA is within Waverley to the north of Farnham. There is a 5km buffer zone, however, and therefore the SPA affects most of Farnham. View a map showing the areas covered by 5km buffer zone.

Avoidance Strategy - Suitable Alternative Natural Greenspace (SANG)

An Avoidance Strategy was adopted in 2009 so that any new housing development in the Farnham area would not have an adverse impact on the SPA. 

This provides an additional 3.45ha of SANG (Suitable Alternative Natural Greenspace) in Farnham Park. This SANG was made available following the adoption of the Farnham Design Statement as a material planning consideration on 20 July 2010.

Following the Executive's decision to release the remaining 6.9ha of SANG at Farnham Park, the Thames Basin Heaths Avoidance Strategy was updated in May 2013 to reflect this change.

Download all the Thames Basin Heaths SPA Avoidance Strategy Associated Documents.

Submitting a planning application within 5km buffer zone in Farnham

If a developer cannot provide bespoke SANG (on or off site), they may be able to pay a SANG tariff to contribute towards the enhancement of existing SANGs, where such sites have been identified by the local authority. Waverley's only current SANG resource is Farnham Park.

Financial contributions to the enhancement of the Farnham Park SANG will need to be secured through an appropriate Section 106 unilateral undertaking.

This must be completed before we can grant planning permission. 

Proposals for residential developments that do not secure the provision of SANGs in accordance with the SPA Avoidance Strategy are likely to fail an Appropriate Assessment. In these circumstances permission must be refused.

Important note: The SANG capacity at Farnham Park is a finite resource in terms of the numbers of new dwellings it can support. At July 2015, the net unallocated capacity stood at 182 dwellings (out of an original total capacity of 1,104). The remaining capacity is monitored continually and the latest position is reported to all meetings of the council’s Western Planning Committee. Where there is insufficient capacity to support proposals for residential development, and unless applicants can provide bespoke SANG elsewhere, permission will be refused.

How much is the SANG tariff?

Use our calculator for assessing the required contribution for avoidance of the impact of development the Thames Basin Heaths Special Protection Area (SPA). 

This page contains

  • the Thames Basin Heaths Special Protection Area (SPA) Calculator,
  • Guidance for completing the Unilateral Undertaking
  • General Questions and Guidance
  • Unilateral Undertaking
  • Checklist for applicants

Contact Information

Planning Policy
Tel: 01483 523291Email:

Page owner: Jennie Falconer. Last updated: 13/08/2015 13:57