Biodiversity Net Gain: Achieving BNG

As it is now a part of UK legislation, Biodiversity net gain (BNG) will become a mandatory point for all upcoming development projects in England. BNG refers to the process whereby a development (or project) considers the environmental impact in terms of biodiversity. It aims to ensure the biodiversity is left in a better state than before the development was completed. This is done by avoiding biodiversity loss, retaining various habitat types and protecting any assets of strategic significance.

Biodiversity Net Gain is being requested more frequently by Local planning authorities to inform a planning application. The aim is to demonstrate how the proposed development will be of benefit to biodiversity in a measurable manner. BNG also acts as a planning condition as well as a policy requirement for planning consent. It can therefore have a significant impact during the decision making process of planning authorities when they debate whether to grant or refuse a planning application.

Utility providers, transport and other organisations are introducing BNG to internal policies to ensure any project will achieve a net gain. Some are even setting greater percentage gain targets than 10%. Those in charge of planning projects will now need to factor in mandatory biodiversity net gain and recognise the importance of development biodiversity.

what is biodiversity net gain

Implementing BNG

If you are unsure of how mandatory BNG may affect your planning application, you should contact your local planning authority immediately. They can discuss your development plans in detail and whether they align with BNG.

If they indicate that your development could be significantly impacted, we recommend that you contact an experienced ecologist as soon as possible. Our ecologists can discuss whether your development plans meet the required standards. They can also recommend any measures you may need to take in order to meet the biodiversity standards.

At Collington Winter, our team has strong experience completing BNG and will provide guidance throughout the planning process. We can ensure that one of our experienced biodiversity ecologists visits your development site to create and develop any necessary BNG plans and any required BNG reports.

Our ecologists will complete a habitat classification assessment, and the data is entered into a metric to measure changes to the natural environment, pre and post development. This metric is currently Defra Metric 4.0. Landscape planting plans and management plans are used to inform post development measures.

Biodiversity Net Gain Principles

According to the Chartered Institute of Ecology and Environmental Management (CIEEM), there are ten crucial good practice principles of biodiversity net gain. These should help to achieve BNG if they are followed accordingly. The mandatory BNG principles include the following:

  • Utilise the mitigation hierarchy to minimise the impact on biodiversity
  • Eliminate any negative impacts on biodiversity
  • Communicate each BNG outcome with complete transparency
  • Cover all areas of sustainability, including societal and economic factors
  • Involve any pre-development and post-development stakeholders in creating mandatory net gain solutions
  • Focus on producing long-term environmental benefits from BNG
  • Understand the variable factors and potential risks in order to achieve biodiversity and deliver net gain
  • Offer nature conservation that exceeds the stated BNG requirements
  • Determine a suitable method in order to secure measurable biodiversity net gains
  • Ensure the best possible results from biodiversity net gain

For case studies and a practical guide on BNG principles, visit the CIEEM website.

Our team has strong experience completing BNG and will provide guidance throughout the planning system process. This applies from the initial land purchase agreements to monitoring assessments.

Calculating Biodiversity Net Gain

Metrics assign every habitat on a site a ‘biodiversity unit value’ according to its relative importance for biodiversity. This enables comparison between the existing value of a site and what will be delivered through development or management and post development. This may include an increase in natural habitats through retention and enhancement and/or creation, which goes over and above the environmental habitat originally on site.

BNG can be calculated through the DEFRA biodiversity metric 3.1, which requires a limited number of factors. These factors include:

 The type of habitat (both on and off site)

  • Any locations (if they are local environment priorities)
  • The size of habitat parcels in kilometres or hectares
  • The condition of any habitat parcels

The government website also provides a biodiversity metric 3.1 calculation tool which can help to determine your biodiversity unit score. This will then translate into the standards of your local planning authority.

The importance of Biodiversity Net Gain

BNG is significant for a variety of reasons and can help to positively affect the environment almost anywhere. Some of the key benefits that biodiversity net gain provides include:

 Enables the production of raw materials

  • Supplies water and oxygen to surrounding ecosystems
  • Enhances the environment’s visual appearance
  • Provides jobs for local farmers and other agricultural occupations
  • Facilitates a scientific understanding of the natural environment
  • Offers recreational activities such as fishing, camping and hiking

The idea of mandatory BNG is a structured and regulated method of prioritising and ensuring that all of the factors listed above are supported and encouraged in the years ahead. As BNG applies to all development projects, it causes a universal approach from governing bodies. Therefore, as BNG is a government policy, it prevents any potential issues with key stakeholders.

Biodiversity Net Gain: The Environment Bill

The Environment Bill was passed this year as it received royal assent. Therefore, BNG will soon become mandatory through the forthcoming Environment Act in November 2023. However, the National Planning Policy Framework also requires a net gain approach which should be achieved in a measurable way.

Within this Environment Bill, it aims to include the development of effective conservation covenants, increase the use of recycling, improve air and water quality, recall products that violate environmental standards, protect local wildlife species, regulate chemicals that may harm the environment, reduce plastic waste and use resources in an efficient manner.

As a result of this Bill, BNG has been served as a core policy with numerous long term effects on ensuring the preservation of habitat types for a minimum of three decades. 

Is Biodiversity Net Gain Mandatory?

The Environment Act received Royal Assent in England in November 2021. It introduces a requirement to deliver BNG for developments in England. There is a two-year transition period before the net gain requirement becomes law (in autumn 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:

  1. b) … 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…”

Numerous Local Planning Authorities have been requesting the assessment for numerous years. Many have introduced or are currently amending local developers plans to ensure it is mandatory as a part of Local Policy.

The Act will require the key points:

  • Developers must deliver a minimum of 10% net gain through their schemes; this will be measured through a metric, currently Metric 3.1.
  • A developer will need to demonstrate how biodiversity gain will be delivered. This will be demonstrated through the production of detailed Landscape Planting Schemes, Landscape Management Plans and Monitoring assessments for on and/or off-site.
  • 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 will be required elsewhere. This will be done through discussions of third party land owners, the council, landbanks or wildlife charities.
  • 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” 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 aim is to get clients to think about biodiversity during the initial land acquisition and design stages and avoid retro-fitting the calculation once designs have been produced. Retrofitting will often lead to delays, unpredicted financial costs and difficulties with planning application determinations.

Biodiversity Net Gain Plans

In order to obtain planning permission for a development from your local planning authority, you must be able to prove that you are taking the correct measures to increase biodiversity net gain. One of the first steps in this process is to book an experienced ecologist to create and develop a biodiversity net gain plan.

Depending on the ecologist’s findings within a BNG assessment, the BNG plan will help to determine natural elements that could potentially be at risk as a result of the development project and any mitigation methods to prevent these outcomes from occurring.

How can Collington Winter assist?

Our team of ecologists and land managers have helped numerous clients over the years, including policy guidance for BNG in England. 

We can assist with biodiversity net gain by providing: 

Please get in touch if you would like further information about BNG. We can also develop land management plans. We are happy to offer free CPD sessions on the BNG principles and how we can help your schemes achieve this.

Our Ecology Director, Olivia Collington, holds a Natural England license. If you would like to find out more about the services we provide, feel free to contact us using the details below.

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