Biodiversity Net Gain Planning Conditions for Development

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 leave the natural environment 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 that BNG should be achieved on site.

Planning conditions for biodiversity net gain

As per the Environment Bill and in accordance with the national planning policy framework (nppf), most planning applications must adhere to a minimum of 10% BNG. This is measured by Defra’s biodiversity metric 3.1, with a requirement for habitats to be maintained for at least 30 years, except for certain exemptions. Alongside these requirements, further implementations were introduced, including:

  • A strengthened legal duty for public bodies to conserve and enhance biodiversity
  • New BNG reporting requirements for local planning authorities
  • Mandatory special strategies for nature described as “Local Nature Recovery Strategies (LNRS).

Further planning conditions may require a survey of the development site’s existing biodiversity, including habitat types and species present. An assessment of the impact that the proposed project will have on surrounding biodiversity and monitoring of the site’s biodiversity over time may also be needed.

When will biodiversity net gain become mandatory?

Once the Environment Act 2021 is enforced, the majority of upcoming developments in England will be obligated to integrate BNG. On 27th July 2023, the government published additional information for developers to deliver the mandatory biodiversity requirement. It also stated that BNG requirements will become effective in January 2024 (with the exception of small sites, which will come into effect in spring 2024).

This legislation will necessitate a 10% net gain in biodiversity for all forthcoming projects in England that require planning consent. The biodiversity metric outlined in the legislation will be used to quantify the net gain. BNG will be applicable to projects affecting ecosystems such as woodlands, wetlands, grasslands, and the built environment, but it will not apply to those exempt from planning permission or covered by specific exemptions.

The introduction of BNG marks a substantial advancement in the preservation and enrichment of biodiversity in the UK. It will serve to ensure that fresh initiatives contribute to the overarching objective of arresting the decline in biodiversity. The inclusion of BNG holds a pivotal position within the UK government’s 25 Year Environment Plan.

Biodiversity net gain principles

According to the Chartered Institute of Ecology and Environmental Management (CIEEM), there are ten crucial good practice principles of BNG. 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 biodiversity net gain requirements
  • Determine a suitable method in order to secure measurable BNG
  • Ensure the best possible results from BNG

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.

Implementing biodiversity net gain

If you find yourself uncertain about the implications of mandatory BNG for your planning application, we strongly recommend reaching out promptly to your local planning authority for more detailed information. They can provide comprehensive guidance on your proposals and whether they align with BNG regulations. In the event that they indicate potential impacts on your project, it is advisable to seek the assistance of an experienced ecologist.

Our team of ecologists possess the expertise to evaluate your project concepts and determine their compliance with the necessary BNG standards. They can also offer guidance on any essential steps required to meet biodiversity criteria.

With a wealth of experience in BNG, our team is well-equipped to assist you throughout the planning process. We can arrange for one of our expert ecologists to conduct an on-site assessment of your development. They can collaborate with you to create and enhance any essential BNG plans and reports.

Our ecologists will carry out a habitat classification assessment, which serves as the basis for determining changes in the natural environment before and after development, utilising the current Defra Metric 3.1. Post-development biodiversity measures are shaped by landscape planting plans and management plans.

Calculating biodiversity net gain

Metrics assign a ‘biodiversity unit value’ to each habitat within a designated site based on its relative significance for biodiversity. This approach to development allows for a comparison between the existing biodiversity value of a site and what will be achieved through development or management efforts, both before and after development. This may encompass the augmentation of natural habitats, surpassing the originally present environmental habitats.

The calculation of BNG can be performed using the DEFRA biodiversity metric 3.1, which relies on a specific set of factors. These factors consist of:

  1. The habitat type (both on and off-site).
  2. The presence of any designated local environmental priority areas.
  3. The size of habitat parcels, measured in kilometers or hectares.
  4. The condition of these habitat parcels.

Additionally, the government website offers a biodiversity metric 3.1 calculation tool, which serves to determine your biodiversity unit score. This score correlates with the standards established by your local planning authority.

Why biodiversity net gain is being required by local planning authorities

BNG is significant for a variety of reasons and can help to positively affect the surrounding environment and wildlife. Some of the main benefits that BNG provides include:

  • It supplies water and improves air quality to the surrounding environment
  • Enhances the visual appearance of the environment
  • Facilitates a scientific understanding of the environment
  • Provides jobs for agricultural occupations
  • Helps to protect special scientific interest sites and irreplaceable habitats

The concept of mandatory planning conditions for biodiversity net gain is a structured method of ensuring that all of the factors listed above are encouraged and supported in the years ahead. As BNG applies to all planning projects, it causes a universal approach from governing bodies and local authorities. Therefore, due to the fact that BNG is a government policy, it prevents any potential issues with key stakeholders.

Biodiversity net gain plans

To secure planning permission from a local authority for a project, it is necessary for developers to demonstrate their commitment to enhancing BNG. One of the first essential steps is to engage an experienced ecologist who can create a biodiversity gain plan.

The BNG plan will be based on the ecologist’s assessment of the project. It will identify natural elements that could potentially be at risk due to the project. The plan will also outline any mitigation measures. This could include habitat recreation or conservation covenants to be implemented to prevent negative outcomes.

By incorporating biodiversity considerations into the initial planning and design stages, the goal is to avoid retrofitting. This can cause delays, unexpected financial costs, and complications with planning application determinations.

How can Collington Winter assist?

At Collington Winter, our team of ecologists and landscape architects have assisted numerous clients over the years to deliver biodiversity net gain on their projects. BNG is something that we are experienced and qualified in, and we can offer advice on your project. We are determined to offer you the support you need in order to reach the required mandatory biodiversity bracket.

Please get in touch if you would like consultation on conditions of planning for biodiversity net gain or BNG plans. We also offer free CPD sessions on the BNG principles and how we can help your project to achieve them.

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

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