SANG: Suitable Alternative Natural Greenspace explained

 

SANG stands for Suitable Alternative Natural Greenspace. It is recreational greenspace provided or secured as part of a strategy to reduce recreational pressure on a protected wildlife site, most commonly a Special Protection Area (SPA).

A SANG is not the buffer zone around an SPA. That was an error in the previous version of this page. The protected site has its own boundary, a local mitigation strategy may define one or more zones of influence around it, and a SANG is the alternative greenspace intended to give new residents somewhere attractive to walk and exercise dogs without adding harmful recreational pressure to the protected habitat.

The best-known example is the Thames Basin Heaths SPA, but SANG-style mitigation is used in a number of other areas. The exact distances, contribution rates, capacity calculations and eligibility rules are local and should never be assumed from the Thames Basin Heaths model.

Farnham is a useful live example of why capacity matters. Waverley’s latest monitoring leaves room for just 16 more homes at Farnham Park, while a new SANG is proposed beside it. Read our Farnham SANG capacity story.

 

Why is SANG needed?

 

Some internationally protected wildlife sites are vulnerable to increased recreational use generated by new housing. Depending on the site, impacts can include disturbance of breeding or roosting birds, dogs leaving paths, trampling, nutrient enrichment, fire risk and other pressures.

Under the Habitats Regulations, the competent authority must be satisfied that a proposal will not adversely affect the integrity of the protected site before it can normally be approved. A strategic package of mitigation can make that conclusion possible where the effect is predictable and the mitigation is sufficiently certain.

SANG is one form of that mitigation. It aims to provide high-quality, convenient and attractive alternative recreational space so that the additional population created by development does not increase pressure on the protected site.

 

SANG is different from SAMM

 

SANG and SAMM are often mentioned together but do different jobs.

SANG provides or improves alternative recreational greenspace. SAMM means Strategic Access Management and Monitoring and normally funds measures associated with managing recreational pressure on the protected site itself, such as wardening, education, monitoring and access management.

A local habitats mitigation strategy may require one or both. Contributions are commonly secured through a planning obligation or other suitable mechanism, but the legal and financial arrangements vary between authorities.

 

The Thames Basin Heaths example

 

The Thames Basin Heaths SPA is the example most often associated with SANG. It protects breeding populations including nightjar, woodlark and Dartford warbler across heathland in Berkshire, Hampshire and Surrey.

The long-established strategic framework includes:

• a general restriction on net new residential development within 400 metres of the SPA
• a requirement for relevant residential development in the wider zone to provide or contribute to SANG
• a requirement for appropriate SAMM measures

For much of the framework the familiar SANG zone is 400 metres to 5 kilometres, although current local strategies can include further provisions for particular scales and locations of development. The relevant local authority’s latest adopted strategy must therefore be checked.

These distances are not national rules and should not be copied onto another SPA or SAC.

 

Does every development near an SPA pay a SANG tariff?

 

No. Liability depends on the particular protected-site strategy, the type of development, its location and whether it would create the impact the strategy is intended to mitigate.

Residential development is the usual focus because additional residents can generate extra recreational visits. But exclusions, exemptions and different approaches can apply to specialist accommodation, replacement dwellings, sheltered housing, HMOs, holiday accommodation and other development. These questions are determined by the current local strategy and the Habitats Regulations evidence supporting it.

Do not assume that a development which is exempt from Community Infrastructure Levy is automatically exempt from a habitats mitigation contribution. CIL and SANG/SAMM are different systems.

 

How much does SANG cost?

 

There is no national SANG tariff. Local authorities publish their own contribution rates and calculation methods, often linked to dwelling size, occupancy assumptions or the capacity and delivery cost of strategic SANG.

Rates can change and strategic SANG capacity can be limited. For property appraisal or development due diligence, check the current local authority tariff and available mitigation capacity rather than relying on an old planning permission or a neighbouring council’s charges.

A larger development may provide bespoke SANG rather than buy capacity in an authority-led scheme. Where new SANG is proposed, its location, accessibility, size, quality, walking routes, car parking where appropriate, long-term management and ability genuinely to divert recreational trips will all matter.

 

SANG and Habitats Regulations Assessment

 

The local planning authority remains responsible for the Habitats Regulations Assessment (HRA). A financial contribution does not itself replace the legal assessment.

At the initial HRA screening stage, mitigation introduced specifically to avoid or reduce effects should not be taken into account. Where a likely significant effect cannot be excluded, the authority moves to appropriate assessment and can then consider the secured SANG/SAMM package when deciding whether adverse effects on site integrity can be ruled out.

This is why planning decisions often contain both an HRA record and a planning obligation securing the mitigation.

 

Buying a property or development site in a SANG area

 

Habitats mitigation can materially affect the viability and timing of a project. Before purchasing or designing a scheme, check:

• which SPA, SAC or Ramsar site generates the requirement
• the current zone of influence and whether the site falls within it
• which development types trigger mitigation
• whether strategic SANG capacity is available
• the current SANG and SAMM contribution rates
• whether bespoke SANG would be needed for the scale of development
• how the contribution or land is secured
• whether any additional ecological assessment is required because the proposal has effects not covered by the strategic mitigation scheme

Strategic mitigation deals only with the impacts for which it was designed. A site can still have separate ecological constraints.

 

Useful related pages

 

For the underlying protected-site rules, see our pages on Special Protection Areas, Special Areas of Conservation and Ramsar sites. For the legal assessment process itself, see our dedicated guide to Habitats Regulations Assessment.

 

Conservation, Heritage & Protected Sites

 

SANG Page Updated: 31st August 2026