About this page
This page provides a short overview of how protected sites should be considered through planning and development. It highlights that protected site legislation is mainly focused on avoiding impacts from development, rather than development helping to deliver improvements to these sites. It explores how relevant legislation and policy could be applied by local planning authorities (LPAs) to ensure development not only avoids impacts, but also has a beneficial impact on protected sites.
IMPORTANT: This page does not provide detailed information on how LPAs should review planning applications or set Local Plan policy for protected sites. Defra and Natural England have provided guidance on how to review planning applications that might affect protected sites and guidance on Habitats Regulations assessments. There is also MHCLG guidance on appropriate assessment and a page on how to use European site conservation objectives and advice.
The Planning and Infrastructure Act 2025 introduced Environmental Delivery Plans (EDPs). Where an EDP is in place, it changes the approach required for development affecting protected sites. This webpage does not cover what local authorities should do where a EDP is in place.
Legislation covering development and land use plans that affect protected sites
Local planning authorities (LPAs) have duties relating to operations they carry out on or likely to affect protected sites and operations they permit that may affect protected sites. ‘Operations’ local planning authorities permit include planning permission. These duties also apply to land use plans, i.e. Local Plans, for European sites.
There is overarching Government guidance on how to review planning applications that might affect protected sites and areas.
The Wildlife and Countryside Act and Habitats Regulations ensure that Local Plan policies are written, and development is designed in a way to avoid and mitigate impacts (and for European sites, compensate for unavoidable impacts as a last resort). It is up to the person carrying out the operation to propose and implement the avoidance, mitigation and/or compensation measures, i.e. the developer in the case of planning applications and local planning authorities for Local Plans. The LPA secures the necessary measures, for example, through a planning condition or S106 for planning permission or for a Local Plan, appropriate wording of a policy or implementing a strategic solution.
Unless an Environmental Delivery Plan is in place, there is no legislative requirement for developers to provide measures that will improve or enhance a protected site, so if the site is not in a favourable condition currently, this is not a mechanism to drive recovery. Hence, the nutrient neutrality approach, which is based on development leading to no change to nutrient levels (not an improvement), i.e. avoiding impacts, but not getting the site back to a favourable condition.
However, LPAs do have a statutory duty to protect and enhance protected sites, which they could choose to meet via their planning decision-making. The best way to make sure that developers do this is likely to be via setting local planning policy.
Note that the current Government policy is that biodiversity net gain cannot be used to enhance designated features of the protected site, except if the habitat is intertidal. So, whilst biodiversity units can be created on and used to create or enhance habitat in protected sites, they can only be used to get a site to favourable condition (i.e. improving the condition of the special features) for intertidal sites. BNG could potentially be used to enhance protected sites by funding habitat creation/enhancement beyond the site boundary.
National planning policy and protected site enhancement
Alongside legislation, National Planning Policy Framework (NPPF) sets the context for Local Plan policies and decision-making on planning applications by LPAs and therefore what developers will provide.
Note that a revised NPPF was published for consultation on 16 December 2025.
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Paragraph 192: ‘plans should:
a) Identify, map and safeguard components of local wildlife-rich habitats and wider ecological networks, including the hierarchy of international, national and locally designated sites of importance for biodiversity; wildlife corridors and stepping stones that connect them; and areas identified by national and local partnerships for habitat management, enhancement, restoration or creation; and
b) promote the conservation, restoration and enhancement of priority habitats, ecological networks and the protection and recovery of priority species; and identify and pursue opportunities for securing measurable net gains for biodiversity.’
- Paragraph 193(b): ‘development on land within or outside a Site of Special Scientific Interest, and which is likely to have an adverse effect on it (either individually or in combination with other developments), should not normally be permitted. The only exception is where the benefits of the development in the location proposed clearly outweigh both its likely impact on the features of the site that make it of special scientific interest, and any broader impacts on the national network of Sites of Special Scientific Interest.’
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Paragraph 193(d): ‘development whose primary objective is to conserve or enhance biodiversity should be supported; while opportunities to improve biodiversity in and around developments should be integrated as part of their design, especially where this can secure measurable net gains for biodiversity or enhance public access to nature where this is appropriate.’
So, with specific reference to protected sites, the NPPF is more about the avoidance of impacts from development rather than improving the sites, though general enhancement of biodiversity through development is encouraged.
Protected Site Avoidance and Mitigation – Existing Solutions
Protected site improvement through development – a way forward?
The Wildlife and Countryside Act, Habitats Regulations and NERC Act include duties for local planning authorities to protect and enhance SSSIs and biodiversity through their functions, but there are no specific references to plan- or decision-making. General enhancement of biodiversity through development is also encouraged by the NPPF.
Local authorities can set policies in their Local Plan that promote or even require enhancement of protected sites to meet their legal duties and NPPF requirements, but it’s not explicitly set out anywhere that they should do this. Developers may also be incentivised to improve protected sites for various reasons other than Local Plan policies, such as meeting Corporate Social Responsibility targets, Nature Positive initiatives and helping to get local communities on board with development proposals.
Links to further information:
DISCLAIMER: The PAS team updates these pages regularly to reflect current guidance on protected sites as best we can. Our goal is to provide accurate, timely information to support local planning authorities. If you are from a local authority and have any questions about the content or need further information, please contact us at [email protected]. This page was last updated on 20/03/2026.