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NPPF Biodiversity Net Gain: National Planning Policy Framework

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The concept of biodiversity net gain in conservation biology refers to the positive outcome of a development project on the diversity of species and habitats in an area. This means that the project not only minimizes harm to the local ecosystem, but actively works towards enhancing the variety of life forms and habitats present.

The goal of biodiversity net gain is to create a net increase in biodiversity, rather than a net loss, as a result of the development project. To achieve this, efforts are made to create new habitats, restore degraded ones, and even relocate species to new locations. The ultimate aim is to improve the overall health and richness of the local ecosystem.

By complying with good practice and the guidelines of biodiversity within their development plans, developers, project and land managers should have more chance of their planning permissions being granted, as this is up to each local planning authority to determine.

Our team of Ecologists are highly experienced with the rules and guidance surrounding biodiversity and can assist clients all across England and Wales. If you are in need of advice or an expert Ecologist to help you with biodiversity net gain requirements, planning policies and decisions then please don’t hesitate to get in touch today.

What is NPPF Biodiversity Net Gain?

Biodiversity net gain plans ultimately ensure developers have to consider the impact their project or development has on the local environment and surrounding irreplaceable habitats. As such, developers must change and adapt their planning decisions and planning conditions to safeguard the local ecosystems and encourage habitat enhancements to ensure no damage is caused.

Leaving an environment in a better condition than it was prior to development is the ultimate aim of biodiversity net gain, and it can be accomplished by creating or enhancing a habitat surrounding and within the development itself.

To obtain planning permission for projects and developments, local planning authorities are commonly asking developers to meet the biodiversity net gain requirements before it becomes mandatory. This is ultimately in hopes that the developers can demonstrate how their project will benefit the environment around them. Complying with biodiversity net gain is a significant factor in whether planning permission is granted or denied.

What is the National Planning Policy Framework?

The National Planning Policy Framework (NPPF) is a set of guidelines in the United Kingdom for the preparation and implementation of local and regional planning policies. It was first published in 2012 and provides a framework for the interpretation and application of national planning policies and guidance for local authorities. The purpose of the NPPF is to promote sustainable development, which includes economic, social, and environmental objectives, and to ensure that development is planned for in a way that is coherent and effective.

The NPPF sets out the government’s planning policies for England and how they should be applied in the preparation of local and neighborhood plans. The NPPF for biodiversity are the guidelines that local authorities and planning developers must follow before BNG becomes mandatory by law in late 2023. It provides a balance between promoting sustainable development and protecting the environment, and is designed to make the planning system more efficient, accessible, and predictable.

Implementing NPPF Biodiversity Net Gain (BNG)

To meet the required biodiversity standards for your local planning authority it is recommended to consult an experienced Ecologist to ensure you are complying to the correct guidance, as guidance varies around the authorities.

Our team of expert Ecologists can visit your development site to provide individualised guidance on how to follow biodiversity net gain planning law. We can also create and provide relevant BNG reports and plans.

What is a Biodiversity Net Gain Condition Assessment?

A biodiversity net gain condition assessment is a process used to evaluate the potential losses and gains of a development project on biodiversity. The assessment typically involves a comprehensive survey of the site and its surrounding area to identify the existing species and existing habitats present, as well as an analysis of the potential impacts of the proposed development on these species and habitats.

The assessment also includes an evaluation of the proposed measures to mitigate negative impacts and enhance biodiversity, such as creating new habitats, restoring degraded ones, or translocating species to new locations. Based on the results of the assessment, recommendations may be made to improve the project design and mitigate negative impacts on biodiversity. The assessment will also include a calculation of the net gain or loss of biodiversity, based on the difference between the baseline conditions of the site and the expected conditions after the development project is completed.

Biodiversity net gain condition assessment is a requirement for most of the development projects as a mean of demonstrating compliance with planning policies and regulations.

Calculating Biodiversity Net Gain

To calculate biodiversity net gain, a predevelopment biodiversity metric score will be given to the land or area to be developed. This score, developed by Natural England, will enable Ecologists to calculate the the existing value of the site in biodiversity units and what BNG will be delivered when the land is developed.

The current version of the metric system is 4.0, and factors that go into the metric include:

  • The type of habitat (both on and off site habitats)
  • Any locations (if they are local environment priorities)
  • The size of habitat parcels in kilometers or hectares
  • The condition of any habitat parcels 

If biodiversity cannot be improved on the land in question then developers can use biodiversity offsetting to improve another area of land as compensation for their development, this is done by the purchase of biodiversity credits.

Biodiversity net gain offsetting is essentially an act that ensures conservation measures are taken to further habitats and environments when biodiversity net gain is unable to take place elsewhere, ultimately compensating for what is lost in a measurable way. Developers will have to ensure that biodiversity is maintained for at least 30 years via conservation covenants or planning obligations. 

When will biodiversity net gain be mandatory?

Local planning authorities require all permissions they grant to achieve at least 10% biodiversity following the Environment Act 2021. A provision for secondary legislation has been put into place from the act, which will set a date in which the mandate will come into force. Currently, the mandate is expected to come into force towards the end of 2023.

The Environment Act 2021 allows a transitional two-year period for local authorities to get their policies and processes smoothly in place before BNG becomes mandatory in 2023.

The current national policy in England, The National Planning Policy Framework (NPPF) Paragraph 179 states:

  • “To protect and enhance biodiversity and geodiversity, plans should:
  • “Identify and pursue opportunities for securing measurable net gains for biodiversity.”

Paragraph 180 states:

  • “When determining planning applications, local planning authorities should apply the following principles: 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” 

Many Local Planning Authorities have already been requesting the assessment for BNG for a number of years already, and many of them are beginning to amend local developers’ processes to ensure they meet the set standards as part of the local policy.

The Act will require the key points:

  • Developers must deliver BNG at a minimum of 10% through their schemes. This will be measured through a metric, currently Biodiversity Metric 4.0. This tool can help to identify your biodiversity unit score and translate it into the standards of local planning authorities.
  • A developer will need to demonstrate how biodiversity gain will be delivered on developed land. This will be demonstrated through the production of detailed Landscape Planting Schemes, Landscape Management Plans and Monitoring assessments for on and/or off-site.
  • A mitigation hierarchy is to be followed and demonstrated to avoid, minimise or compensate. If it is not possible to compensate on the development site, then offsetting on other designated sites will be required elsewhere.
  • Developers will have to guarantee the biodiversity gain is maintained for at least 30 years (as outlined in Landscape Management Plans).
  • New “local nature recovery strategies (LNRS)” will be prepared to geographically cover England by “responsible authorities”. This will encourage habitat creation and enhancement in the right places.
  • Conservation covenants will be a mechanism used to deliver this (this approach is in preparation by Defra and Natural England).
  • A national register of land used for biodiversity gain will be established. This will involve setting up a new biodiversity credits market.
  • Metrics are only concerned with habitats and do not take protected species into consideration.
  • Other ecological legislation and policies still apply.


The Environment Bill ultimately endeavors to encourage developers to think about the mandatory biodiversity net gain before and during the acquisition of land to avoid changing plans and calculation further down the line once processes have already begun. Having to adapt an on-going development to meet BNG will lead to delays and financial loss to name but a few problems they may encounter. 

How can we help with NPPF biodiversity net gain?

Taking measures that prove you are trying to increase NPPF biodiversity net gain within your development project will further your chances to gain the required planning permission from your local authority when biodiversity net gain is mandatory. Getting ahead of legislation and keeping up to date with the guidelines in the NPPF biodiversity net gain plan and upcoming laws surrounding the Environment Bills will ensure your development project runs as smoothly as possible.

At Collington Winter, our team of ecologists are experts in the field of biodiversity net gain and can keep you up to date with new and changing legislation. As regulations can vary across local authorities it is important to instruct a qualified ecologist to ensure you are following the correct rules.

Our team’s experience and qualifications in BNG means we can support our clients pre and post development in order to reach the required mandatory biodiversity net gain bracket that is becoming law in autumn 2023.

Our biodiversity net gain consultants have helped numerous clients over the years. Achieving BNG and avoiding biodiversity loss through development is something that we are experienced and qualified in. We can offer advice on planning projects and landscape management plan requirements.

Some of the additional services our team can offer include:


To find out more how our team can help you with your biodiversity plans then please do not hesitate to get in touch with us to discuss your queries. You can email our Ecology Director, Olivia Collington, at or use the form below and a member of our team will be in touch with you.


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