Biodiversity Net Gain

Biodiversity Net Gain, or BNG, is a new obligation that applies to most planning applications and will apply to DCOs from November 2025. Developers are required to improve biodiversity by at least 110% compared with what is being lost by the development.

What is Biodiversity Net Gain and how to prepare for it?

Since the start of April 2024, the Biodiversity Net Gain (BNG) obligation has applied to most planning permissions and will do so for all development consent orders (DCOs) from November 2025. BNG is a new mandatory condition that must be attached to all planning permissions , where any habitat lost by the development must be replaced with enhanced habitat elsewhere. The main principle of the approach is to assess the ecological value of the habitat that will be lost to development (calculated by a metric developed by Natural England) and implement measures to enhance biodiversity elsewhere, such that they will deliver a minimum of a 10% net gain over time. There must be a commitment to maintain the new habitat in its target condition for at least 30 years.

Some local authorities may have stricter policies than the statutory minimum of 10% net gain. You can check your local authority’s BNG policies via our ta ble which contains links to England’s 317 local councils’ and 10 national park authorities’ references to BNG.

Full details of the new regime are set out in Schedule 7A of the Town and Country Planning Act 1990.

Does mandatory Biodiversity Net Gain apply to my project?

Disclaimer: This tool is not intended to give definitive advice or to be acted upon in isolation.

Are you making a planning application or getting permission some other way?

Planning Application

Some other way

Is it a householder application?

For the definition of “householder application”, please click here.

Yes

Is it to create a biodiversity gain site?

For the definition of “biodiversity gain site”, please click here.

Yes

Are you applying for temporary permission and the loss of habitat will be fully restored within two years?

Yes

Is it exclusively for self-build or custom build residential development?

For the definition of “self-build or custom build”, please click here.

Yes

Is it for fewer than 10 dwellings and the red line boundary is less than 0.5 hectares?

Yes

You must work out the habitats present on the site.

Do the following all apply: there is no priority habitat impacted; there is less than 5m of hedgerow impacted; there is less than 5m of watercourse impacted; and there is less than 25sqm of habitat of non-zero distinctiveness impacted?

↓

“Impacted” means its score in biodiversity units will be reduced by the development. For the definition of “priority habitat”, please click here to download the documentation.

Yes

Mandatory BNG does not apply yet

Disclaimer: This tool is not intended to give definitive advice or to be acted upon in isolation.

Please feel free to get in touch to instruct us to provide you with legal advice on the BNG regime using the form below.

BNG Questionnaire v2

Who will be affected by the BNG requirements?

Anyone considering making a planning application, or a DCO application after November 2025 will be directly affected. All but the smallest developments (affecting less than 25 square metres of habitat) will need to comply with the BNG regime, even change of use applications if the onsite biodiversity value is impacted.

But this new regime brings opportunities as well as obligations. Any surplus biodiversity units can be put on the register and used for other developments, thus helping to offset development costs. Government research shows that each unit could be worth at least £20,000, depending on the rarity of type of habitat, so this could prove quite lucrative.

Environmental organisations and charities may well want to provide biodiversity land that furthers their own aims. This land could be very valuable to developers looking to discharge their BNG obligations. Entrepreneurs could also start trading in biodiversity units and many are setting themselves up to do so.

Environmental consultants will need to be ready to advise on and endorse biodiversity metric scores and assist with finding sites that will meet the BNG objective.

It is essential to get to grips with this regime, whether you have made or are expecting to make a planning application, are hoping to earn money from developers looking for enhanced habitat, either as a landowner or broker, or work for a local authority planning team.

Use the buttons below to find out what opportunities and implications lie ahead.

bng for property developers

bng for landowners

bng for local authorities

How will BNG work?

This regime obliges a biodiversity gain plan to be provided and implemented to secure the BNG before the development can start.

Land affected by development will be given a score in ‘biodiversity units’ for its biodiversity value. This metric also allows the ‘after’ score for land, either onsite or offsite, to be calculated with reference to how difficult any improvements are to implement, how long they will take and how far away the land is.

Although habitats don’t need to be replaced like for like, the rules get stricter for rarer habitats and all habitats must be replaced by those with an equal or higher ‘distinctiveness.’ Some ‘irreplaceable’ habitats, such as ancient woodland, are considered separately because of their exceptional value.

If there is no suitable land for improved biodiversity at the site, then it is possible to improve, or pay someone else to improve, land that is further away by using land on a national ‘biodiversity gain register.’ The Government is hoping a market will be created for buying and selling biodiversity land via this register, however, if there is no suitable land on it, it will be possible to pay the Government for ‘biodiversity credits’ to discharge the BNG obligation, but these have been set at a deliberately high level – £84,000 per unit rising to £1.3m depending on the rarity of the habitat.

read our faqs

Read on for a selection of case studies which explore in detail the practical implications of BNG.

A commercial development in central London

How will regulation affect commercial developments in central London?

A housing development of no more than nine dwellings.

Does the obligation to provide biodiversity net gain for small developments differ?

View more here

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How can we help?

advising businesses on opportunities presented by the new market in biodiversity units;

offering direct advice on how the BNG regime will affect your plans;

educating consultants on matters such as BNG scoring and finding alternative land;

acquiring land, improving it and adding it to the national biodiversity gain site register; and

advising charities on how they can get involved in the BNG regime for charitable purposes.

BDB Pitmans is at the forefront of advising a wide range of clients on BNG and we have been following the development of the regime closely. We are producing document templates for all the additional documentation you will need to navigate this regime. Our team are currently working with surveyors, consultants, companies and charities to ensure that they are up to speed on what BNG means for them and how to comply with their new obligations.

WHY CHOOSE BDB PITMANS FOR BNG ADVICE?

1 We are recognised as leading experts and have consistently achieved independent recognition for our expertise in planning, agricultural and rural affairs, and environmental law.
- The firm is highly ranked by Chambers & Partners for Planning and Agriculture & Rural Affairs
- Various members of our team are also individually ranked by Chambers for their expertise in Planning and Agriculture & Rural Affairs
- We are also highly ranked by the Legal 500 for Real Estate – Planning, Real Estate – Environment & Planning, and Real Estate – Environment
- Partner and Planning specialist Angus Walker is recognised by the Legal 500 and Chambers & Partners as a Leading Individual in the field of planning.
- Angus Walker is also one of the UK’s leading experts on Development Consent Orders
2 We are a full service firm that can offer a holistic view of these complex matters

Our expertise covers areas including planning, environmental law, agriculture and rural affairs, commercial law, and dispute resolution. We can support you with all your legal requirements in relation to BNG, plus your wider personal and business interests.
3 We offer commercial advice deeply rooted in the realities of the rural sector

Every decision you make needs to make sound commercial sense. Our BNG lawyers understand this, so our advice will also have a strong commercial slant drawing on decades of our experience advising landowners and rural businesses.

We can help you make the most of the new regime’s opportunities while protecting your personal connection to, and financial investment in, your land.