Practical Guide to Biodiversity Net Gain

In recent years, there has been a growing concern for the environment, with a need to promote sustainable development practices. The UK town planning system has responded to this need by introducing a new approach known as Biodiversity Net Gain. This approach aims to enhance the natural environment while promoting sustainable development.

What is Biodiversity Net Gain?

Biodiversity Net Gain is a policy approach that requires developers to improve the ecological value of a site by creating new habitats or enhancing existing ones. The goal is to achieve a measurable improvement in biodiversity as a result of development. Simply put, Biodiversity Net Gain ensures that the natural environment is not harmed by new developments, but rather, it is enhanced.

How does it work?

The first step is to identify the existing biodiversity in an area and set a target for improving it. This could involve creating new habitats, such as wetlands, woodlands, or meadows, or enhancing existing habitats to make them more suitable for wildlife. The new habitats should be designed to provide a range of different environments and habitats to support a diverse range of species.

Once the target is set, developers must ensure that the biodiversity net gain is achieved. This could be through a range of measures such as planting native trees and shrubs, installing bird boxes and insect hotels, creating ponds, or providing green roofs. The development should also be designed to allow species to move through the area, creating connectivity between habitats.

How do you calculate Biodiversity Net Gain?

Calculating biodiversity net gain involves assessing the baseline biodiversity of a site before a development project takes place, and then determining the impact of the project on that biodiversity. This can be done using a variety of tools, such as habitat assessments and species surveys, which help to identify the key habitats and species present on a site. Once the impact of the project has been assessed, the net gain can be calculated by comparing the baseline biodiversity with the post-development biodiversity, and determining the difference.

What is the legislation behind BNG?

The requirement for Biodiversity Net Gain in the planning system is outlined in sections 98-101 of the Environmental Act 2021 and schedules 14 & 15. These sections require the creation of a biodiversity gain plan, a biodiversity gain statement, and a register of biodiversity net gain sites.

The objective BNG is met when the biodiversity value of the development exceeds the pre-development value by at least 10%. Any habitat enhancement must be maintained for at least 30 years after completion.

How much Net Gain is required?

The UK government has announced that Biodiversity Net Gain will become mandatory for specific developments in England from February 2024 onwards. This means that developers will need to demonstrate that they have achieved a 10% net gain in biodiversity compared to the baseline condition of the site.

The requirement applies to new planning applications as outlined below, subject to the finalized details in the regulations:

major development from 12 February 2024
non-major development from 2 April 2024
NSIPs from no later than November 2025

The requirement for BNG when it becomes mandatory only applies to new applications, it will not apply to applications pending in the planning system.

As of now, there are no established effective dates for the application of biodiversity net gain (BNG) requirements to retrospective planning applications or alternative permission pathways such as ground (a) enforcement appeals or local development orders.

Some categories of development will be exempt from meeting the legal minimum BNG standards, these are:

Permitted development rights
Householder applications
Development which only has a ‘de minimis’ impact on habitats
Developments undertaken for the purpose of fulfilling the BNG planning condition for another development
High-speed railway network
Certain self-build and custom build developments

The primary legislation establishing the statutory framework for biodiversity net gain (BNG) in England is principally set out in Section 90A and Schedule 7A of the Town and Country Planning Act 1990. This legislation was inserted by Schedule 14 of the Environment Act 2021 and has since been amended by the Levelling Up and Regeneration Act 2023 and the Biodiversity Gain (Town and Country Planning) (Consequential Amendments) Regulations [2023].

What are the key aspects of Biodiversity Net Gain?

One key aspect of biodiversity net gain is the development of green infrastructure, which is a network of green spaces, parks, and other green assets that provide a range of benefits to the environment and local communities. Green infrastructure can help to reduce the impacts of climate change, improve air and water quality, and provide habitat for wildlife. It can also provide opportunities for recreation, exercise, and social interaction. Take a look at our article on What is the Green Infrastructure Framework where one of the key benefits of the framework is the improvement of biodiversity and habitat conservation.

Another important aspect of biodiversity net gain is the integration of wildlife-friendly features into the design of new developments. This could include incorporating green roofs, rain gardens, and other types of green infrastructure into new buildings, as well as designing roads, paths, and other infrastructure to take into account the needs of wildlife. For example, providing underpasses or overpasses for wildlife to cross roads safely can help to reduce the impacts of roads on wildlife populations.

Biodiversity net gain can also be achieved through the use of sustainable materials and construction techniques. For example, using permeable pavements can help to reduce the amount of runoff from new developments, which can help to improve water quality and reduce the impacts of floods. In addition, the use of green technologies, such as solar panels, wind turbines, and rainwater harvesting systems, can help to reduce the carbon footprint of new developments and promote sustainable living.

Benefits of Biodiversity Net Gain

The benefits of Biodiversity Net Gain are many. By enhancing the natural environment, it can help to improve air and water quality, reduce the risk of flooding, and provide a range of benefits for human health and wellbeing. It can also help to create more resilient ecosystems that are better able to adapt to the impacts of climate change.

Moreover, biodiversity net gain can help to protect and enhance the local biodiversity, which is essential for maintaining healthy ecosystems. It can also help to create new habitats and restore degraded ones, which is particularly important given the current rate of habitat loss and species decline.

How do developers incorporate Biodiversity Net Gain?

Developers looking to implement biodiversity net gain principles in their projects will need to work closely with environmental consultants and ecologists, who can provide expert advice on the best methods for assessing biodiversity and mitigating the impact of development. Additionally, it is important to engage with local communities and other stakeholders to ensure that the project meets their needs and expectations.

There can be onsite and off site provision for BNG depending on the circumstances. It’s worth engaging with the relevant Councils’ Ecologist for further information.

How can Planning House Help?

A town planner can provide you with the guidance you need for a smooth transition please feel free to CONTACT US to discuss your situation. We’re not experts in flood risk however we work with some great consultants who are!

If you’re not sure we’re the right fit for you then take a look at our blog on When to Hire a Town Planner and our download on choosing a Town Planner to help you find a town planner that’s right for you.

Related Content

We have much more information for you in our series of eBooks and Practical Guides which cover everything from the very basics of town planning to application processes and what developers need to consider.

We also have BNG specific articles including: