Biodiversity is the term used to describe the variety of life on earth, including all species of plants and animals, their genetic variation, habitats and the ecosystems they are part of. It includes not just the rare or the threatened but also the wildlife that is familiar to us.

The planning system plays an important role in helping to protect the natural environment. This is demonstrated by planning policy and legislation relating to biodiversity.

Government policies

The National Planning Policy Framework (NPPF) sets out the government’s planning policies for England and how these are expected to be applied.

Section 15 “Conserving and enhancing the natural environment” explains how planning policies and decisions should contribute to and enhance the natural and local environment. It describes how to protect and enhance biodiversity, and geodiversity (the variety of rocks, minerals and landforms and the processes which have formed these features throughout geological time).

The NPPF is accompanied and complemented by Office of the Deputy Prime Minister (ODPM) circular 06/05 on biodiversity and geological conservation. This provides guidance on the application of the law relating to planning and nature conservation within England.

Biodiversity is also protected through Section 40 of the Natural Environment and Rural Communities Act of 2006.

Protected species

In England, rare, notable or endangered species of plants and animals are protected under a range of legislation and planning guidance.

A variety of species of wildlife referred to as European Protected Species (EPS) are protected under the Conservation of Habitats and Species Regulations 2017 as amended (known as the Habitats Regulations). These include:

  • otters
  • bats (all species)
  • great crested newts
  • dormice

Legally, any development affecting these species has to be subjected to three tests under the Habitats Regulations. To satisfy these tests, planning applications need to include a survey for the relevant species; and if present a mitigation strategy which satisfactorily demonstrates that the proposal will not be illegal or adversely affect the species.

Applicants should be aware that if protected species are not considered at the early stages, and before the application is submitted, their proposals may lead to significant delays further in the planning process.

Read more in our draft Supplementary Planning Document (SPD) – Biodiversity and planning: guidance for new developments.

Protected species and historic buildings

Historic buildings can often be a home to wildlife such as bats, barn owls and other nesting birds.

When making an application for planning permission or listed building consent it is often necessary to submit an assessment carried out by an appropriately licensed ecologist to show if bats are likely to be present in the building(s) and if so, how they would be affected by the proposals. As stated above, this may lead to the requirement for more detailed surveys and mitigation strategies if bats are found.

Building owners should also consider the needs of protected species when carrying out works to their buildings which do not require permission, such as minor repairs in roof spaces. Complying with the relevant law by protecting species, including obtaining and complying with the terms and conditions or any licences required, is compulsory even where planning permission is not required.

Great Crested Newt District Level Licencing Scheme (DLL)

DLL is a new strategic approach to licensing for great crested newts (GCN).

Traditional licensing requires on site mitigation measures to be carried out. However, this can delay development as some measures can only be carried out at certain times of the year.

DLL does not require on site mitigation; instead developers make a payment based on the impact of their development. This conservation payment is used to create compensatory habitat off-site, which is targeted to areas where it will most benefit GCN.

Across South Gloucestershire there is a Natural England led scheme and applicants will need to enquire with Natural England to confirm their eligibility to use DLL. Read more in our draft Supplementary Planning Document (SPD) – Biodiversity and Planning: guidance for new developments.

Other species, such as slowworms, grass snakes or water voles, and particular species of birds and plants also have varying degrees of protection under the Wildlife and Countryside Act 1981 (as amended) and Countryside and Rights of Way (CROW) Act 2000.

Badgers and their setts are protected under separate legislation (protection of Badgers Act 1992 on

Protected sites

South Gloucestershire contains a network of nature conservation sites which are protected in law (or under planning policy) for their local, national or international importance for wildlife.

The Severn Estuary is internationally important for a range of species and assemblages of waterfowl and a variety of marine and inter-tidal habitats and species. In recognition of this, it is designated as a Special Protection Area and a Special Area of Conservation under European Directives. It forms part of a network of sites across Europe known as ‘Natura 2000’ or ‘European’ Sites. Any development affecting the Severn Estuary European Site will be subject to assessment under the Habitat Regulations 2010 as part of determining the application.

South Gloucestershire also contains over 20 Sites of Special Scientific Interest (SSSI), protected under the Wildlife and Countryside Act 1981 (as amended) and over 300 ‘Local Sites’. This is a catch-all phrase for sites which have been identified as being locally or regionally important for their:

  • species and habitats – Sites of Nature Conservation Interest (SNCIs)
  • geological features – Regionally Important Geological Sites (RIGS)

Whilst not protected in law, these sites are designated through a partnership of statutory and non-statutory nature conservation bodies and are protected under policy PSP19 of the South Gloucestershire Local Plan. The advantage of this is that they are given additional policy protection by being part of the council’s statutory development plan due to the status given to such plans under planning law. This means that, development resulting in significant harm to SNCI and RIGS will be refused unless the mitigation hierarchy has been appropriately complied with.

Some of these sites are also designated as Local Nature Reserves to give people the opportunity to get closer to nature and learn about wildlife.

Where applicable, we expect planning applications to be supported by the relevant ecological surveys to satisfactorily demonstrate that development will not adversely affect local biodiversity. Details on the type of surveys required, their methodology and scope is provided in our draft Supplementary Planning Document (SPD) – Biodiversity and planning: guidance for new developments.

Biodiversity Net Gain (BNG)

Biodiversity net gain is an approach to development which means that habitats for wildlife must be left in a measurably better state than they were before the development occurred.

Achieving biodiversity net gain means that Priority Habitats will need to be extended or improved as part of the development process. Developments will need to be designed in such a way that provides benefits to both people and nature and also reduces impacts on the wider environment.

Under the Environment Act 2021, all planning permissions granted in England, with a few exemptions, will have to deliver 10% biodiversity net gain from November 2023. BNG will be measured using Defra’s biodiversity metric and habitats will need to be secured and monitored for at least 30 years.

More detailed guidance including our interim objectives in relation to Biodiversity Net Gain and our approach to assessment within the planning process, pending further clarification from government, is set out in section Chapter 6 and 8 in our draft Supplementary Planning Document (SPD) – Biodiversity and planning: guidance for new developments.

Our vision for nature recovery of ‘More, Bigger, Better and Joined Up habitat for wildlife’ is set out in the South Gloucestershire Biodiversity Action Plan (BAP) and our Green Infrastructure Strategy 2021 – Greener Places.

More information on Biodiversity Net Gain (BNG)

Purple and yellow wildflowers in a meadow

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Why we need to do more

Despite legislation and policy to protect biodiversity and wildlife, the most recent State of Nature report, published in 2019, suggests there has been a steep 13% decline in the average abundance of wildlife in the UK since the 1970s. This is due to a range of factors including changes in agriculture, development, and climate change. The scale and pace of this nature loss is causing critical impacts on the natural systems on which all life on earth depends. Locally, nationally, and globally it is recognised that urgent and more action is needed to respond to the Climate and Nature Emergency.

Although in the UK certain sites and species are protected, there are limited mechanisms to value, maintain, enhance and create wildlife habitats beyond protected sites. As a result, most habitats continue to be lost to development and this reduces nature’s ability to connect and thrive.

What does BNG look like?

In the future, most developments will need to deliver a minimum 10% BNG. BNG requires an overall increase in biodiversity that is additional to existing habitat and species protections. Implementing BNG requires following the mitigation hierarchy of avoid, mitigate, compensate. This means that avoiding impacts on biodiversity is the first priority, and that BNG is delivered on site where possible, with off site a last resort.

BNG aims to create new habitat as well as enhance existing habitats, ensuring the ecological connectivity they provide for wildlife is retained and improved.

Development often results in impacts on, and losses of, nature. By reinforcing and complementing the mitigation hierarchy, mandatory BNG requires development to deliver more for nature; setting a requirement to increase biodiversity by a minimum of 10% compared to the baseline. This means there will be more and better-quality places for wildlife to live and thrive and for people to enjoy.

BNG can be delivered on site, off site, or via credits and must be maintained for a minimum of 30 years.

How do you measure BNG?

BNG is measured using the Biodiversity Metric. This tool is intended to be used by an ecologist. It uses changes in the extent and quality of habitats as a proxy for biodiversity and compares the habitat found on a site before and after development.

Four key factors underpin this comparison:

  • habitat size
  • condition
  • distinctiveness
  • location

What is a Biodiversity Net Gain Plan?

The BNG plan is a strategy for achieving BNG, including information not captured in the biodiversity metric such as species factors, habitat management plans and how the net gains will be managed and maintained, whether that be on site, offsite or via statutory credits.

BNG scheme design and the planning process

Pre application:

  • select site and assess the likely ecological impacts of the scheme
  • use Biodiversity Metric to assess different scheme designs
  • follow the mitigation hierarchy

Application and determination:

  • submit a Biodiversity Net Gain Plan
  • has the mitigation hierarchy been applied?
  • any land used to deliver BNG off-site will need to be secured for a minimum of 30 years
  • off-site BNG will need to be formally registered on the Biodiversity Gain Site Register

If above is acceptable then BNG Plan will be secured with a condition.


Implement scheme and manage, monitor and report on BNG delivery for the duration of the BNG agreement. 

What happens when we cannot achieve BNG

There will be times where achieving net gain cannot be delivered on-site and suitable compensation will need to be agreed with us (this will be discussed and agreed on a case-by-case basis). It is the responsibility of the developer to deliver any offsetting requirements, even if it requires purchase of additional land to deliver the net gain off-site.

The three main offsetting options include the applicant:

  • purchases additional land to offset
  • pays a Biodiversity Sum to us
  • pays a sum to a third-party habitat broker

Table 3 in chapter 8 of the draft Biodiversity and Planning SPD sets out the various potential offsetting options in more detail. However, as BNG is still in a transitional period some options are not currently available. We intend to list local third-party habitat brokers as and when they become available. The Bristol Avon Catchment Market is open for expression of interest for environmental credit requirements.

We do not have to offer to take on the responsibility of delivering off-site net gain, however where we decide to do this the applicant will be required to pay a Biodiversity Sum for delivering and taking on full responsibility for the offset requirement.

The Biodiversity Sum is calculated based on the Biodiversity Units resulting from the biodiversity metric calculation. It covers the agreed works (habitat creation, enhancement and restoration, long-term management) required to be delivered by us (or council-appointed third party).

It should also be noted that:

  • the final Biodiversity Sum will include a 15% administration fee
  • a S106 Agreement will be used to transfer the Sum alongside a trigger point
  • all other offsite options will be subject to a 10% admin fee

Full details about the biodiversity metric calculation and what administration fees cover can be found in the draft Biodiversity and Planning SPD.

Biodiversity units are priced according to predictions from market assessments. Market analysis done by Eftec, commissioned by DEFRA has indicated the price of £25,000 is realistic to cover habitat creation costs. Therefore, the Biodiversity Sum required for 1 Biodiversity Unit will be in the range of £20,000 to £25,000 (index-linked) to be agreed with developers through the planning application determination process.

The bigger picture

Nature is important in its own right, but it is also essential for the processes that support all life on Earth. The natural environment provides benefits to us all through ecosystem services.

BNG links to a range of Council priorities including:

  • action to respond to the Climate and Nature Emergency
  • place-making to create more greener and nature rich places where people and nature thrive
  • planning, design and management of high quality green infrastructure to increase benefits across priorities
  • access to greenspace and nature
  • mental and physical health and wellbeing
  • resilience to flooding, high temperatures and drought
  • improving air and water quality

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