Sites of Special Scientific Interest (SSSIs) and planning

 

A Site of Special Scientific Interest (SSSI) is land notified because of its special interest for wildlife, geology or physiographical features. SSSIs are the principal national nature-conservation site designation in England and are legally protected under the Wildlife and Countryside Act 1981, as amended.

Natural England notifies SSSIs and identifies the features for which each site is special. A site may also carry other designations: many SPAs and SACs overlap SSSIs, but the legal tests are not interchangeable. A National Nature Reserve may also be notified as an SSSI, while Local Wildlife Sites and Local Geological Sites sit at the local rather than national tier.

Separate statutory controls can overlap as well. For example, protected limestone pavement may be covered by a Limestone Pavement Order as well as forming part of an SSSI.

Development does not have to be physically inside an SSSI to matter. Both the legislation and the August 2026 NPPF recognise that operations outside a protected site can damage its special features.

 

Why is an SSSI designated?

 

An SSSI notification identifies the special interest features of the site. These can include particular habitats, species assemblages, geological exposures, landforms or other scientific features.

The notification is therefore more useful than the label alone. Two SSSIs can be vulnerable to completely different things. One may depend on water levels, another on undisturbed breeding habitat, another on particular grassland management and another on the continued exposure of geological strata.

Natural England’s designated-sites system and MAGIC provide boundaries and site information for English SSSIs.

 

Planning permission and SSSI consent are not the same thing

 

The former version of this page suggested that an applicant simply needed Natural England’s consent whenever planning permission was required. The legal position is more structured.

Owners and occupiers of SSSI land are notified of operations requiring Natural England’s consent – often abbreviated to ORNECs. Under section 28E of the Wildlife and Countryside Act, an owner or occupier must not carry out or permit a listed operation without the required consent unless another statutory route applies.

Where a public authority is itself proposing works likely to damage SSSI features, the separate assent procedure applies. And where a public body such as a local planning authority is considering whether to authorise another person’s operation which is likely to damage the special features, section 28I requires consultation with Natural England before permission is granted.

This means planning permission, Natural England consent and public-body consultation need to be understood together rather than treated as a single generic permission.

 

Natural England consultation on planning applications

 

Where a planning proposal is likely to damage the special interest features of an SSSI, the local planning authority must notify Natural England and take its advice into account. If the authority proposes to grant permission contrary to Natural England’s advice, additional notification and waiting requirements apply.

Natural England’s SSSI Impact Risk Zones (IRZs) help planning authorities decide when consultation is needed. The zones are not simple fixed buffers. They vary according to the sensitivity of the particular SSSI, the type and scale of development and potential impact pathways such as air quality, water, disturbance or loss of off-site supporting habitat.

The current IRZ layer is available through MAGIC. It is a screening tool for consultation risk, not a substitute for ecological assessment.

 

What does the August 2026 NPPF say about SSSIs?

 

Policy N6(1)(b) treats an SSSI as a site of national importance. Development affecting an SSSI should only be supported where:

• there would be no adverse effect, alone or in combination, on the site’s features of special scientific interest; or
• the benefits of the development in the proposed location clearly outweigh both the likely impact on the special features and any broader impact on the national network of SSSIs; or
• the relevant impact is being addressed through a made Environmental Delivery Plan and the developer has committed to the nature restoration levy.

N6(3) is equally important: the policy applies to development inside or outside a designated area if it would affect the biodiversity or geodiversity value concerned.

 

A development outside the boundary can damage an SSSI

 

There is no universal distance within which all development is unacceptable. The relevant question is whether the proposal has a pathway capable of affecting the notified features.

Examples can include changes to drainage or groundwater, polluted runoff, air deposition, recreational disturbance, increased fire risk, noise, lighting, loss of land used by designated species or physical changes to a watercourse feeding the site.

This is why the Impact Risk Zones use different distances and thresholds for different development categories rather than one generic buffer.

 

What if the SSSI is also an SPA or SAC?

 

Many internationally important sites are also notified as SSSIs. In that situation the Wildlife and Countryside Act regime remains relevant, but the Habitats Regulations may impose the additional Habitats Regulations Assessment process.

Passing the SSSI planning-policy test does not remove the need to satisfy the Habitats Regulations, and vice versa. The different designated features should be identified and assessed under the correct regime.

 

SSSIs and permitted development

 

An SSSI is not automatically Article 2(3) land merely because it is an SSSI. However, individual permitted development classes can contain their own restrictions affecting SSSIs or protected sites, and carrying out an operation on SSSI land may separately engage the Wildlife and Countryside Act consent regime.

Do not therefore infer that a proposal is safe simply because a GPDO right appears available. The particular class, SSSI notification and any other overlapping designation all need to be checked.

 

SSSIs and Environmental Impact Assessment

 

An SSSI is a sensitive area under the Town and Country Planning (Environmental Impact Assessment) Regulations 2017.

Where a project is of a description in Schedule 2 and any part is to be carried out in an SSSI, the normal Schedule 2 size or other threshold does not have to be exceeded before screening is required. That does not make EIA automatic; the screening question remains whether significant environmental effects are likely.

See EIA screening and scoping.

 

Relevant legislation and guidance

 

• Wildlife and Countryside Act 1981, as amended – particularly the section 28 provisions
• Natural England: SSSI Impact Risk Zones
• Natural England: protected-site consent and assent requests, April 2026
• National Planning Policy Framework, August 2026, especially N6

 

Conservation, Heritage & Protected Sites

 

Sites of Special Scientific Interest Page Updated: 20th August 2026