Biodiversity Net Gain – What it is and How to Achieve it

Biodiversity net gain (BNG) is a method for ensuring any new development helps to create, preserve, and improve the natural habitat by at least 10%. It affects property developers, land managers, grounds maintenance specialists, and local planning authorities and became mandatory in England in January 2024 under the Environment Act 2021.

With BNG, developers are legally obliged to address the environmental impact of their actions so that biodiversity across a site is left in better condition than when it was found. It also forced grounds maintenance specialists like Grounds Care Group to alter their landscape maintenance programmes by adopting eco-friendly approaches that deliver measurable results.

But what is biodiversity net gain, and what does it mean? This guide will explore new BNG regulations and focus on how to achieve biodiversity net gain.

What Does Biodiversity Mean?

Biodiversity refers to all living things in one natural habitat including humans, animals, plants, and bacteria. However, there is a major risk of these important ecosystems being damaged or affected by developers without the right rules and restrictions in place.

As more and more industries place environmental protection at the top of their agenda, developers now have a legal obligation to clearly demonstrate the steps they have taken to protect and enhance the biodiversity of key habitats during the process of their work. As a legal mandate, the law applies to both planned and sought-after developments.

What is Biodiversity Net Gain?

Biodiversity Net Gain describes the process of increasing the biodiversity value of a development site. It can be achieved both onsite and offsite and even as development work continues.

BNG was optional until the UK Government passed the Environment Act in 2021 forcing all new developments that apply for planning permission to improve the biodiversity of the site by a minimum of 10%. At present, BNG only applies to England with other UK countries expected to follow at some point.

The ‘net gain’ aspect means the development site must enhance its biodiversity value so that natural habitats can flourish, rather than decrease it by negatively impacting the local environment. BNG has become an important strategy for aligning development with conservation goals by ensuring natural habitats are left in a better state after development than before it. In England, it is now mandatory for developers to demonstrate BNG in working practice. At the time of writing, financial penalties and fees for developers who ignore BNG or fall short of set targets were before parliament for discussion.

Why is Biodiversity Net Gain Important?

The protection of key natural habitats during development and maintenance is the driving force behind BNG. By making BMG mandatory for developers, the government will be able to monitor natural habitats and ensure they are nurtured and enhanced for future generations.

Biodiversity Net Gain is important for several reasons including:

1. Quantifiable Measurement

Measuring the biodiversity of a site before and after development will provide vital data that can quantify the biodiversity value of the specific habitat. This is achieved by using standardised assessment tools and metrics, which we’ll discuss later. However, BNG is not about encouraging developers to avoid damaging the biodiversity of a habitat, but more to achieve an overall increase in biodiversity going forward.

2. Offset Losses

Where groundwork leads to a reduction in biodiversity, BNG requires developers to compensate for the loss and reverse the decline of a natural habitat that will result in net gain. Planting native vegetation or creating new habitats are some of the actions that developers can take to mitigate their environmental impact.

3. Legal Compliance

Biodiversity Net Gain is being increasingly incorporated into environmental policies and government regulations. It is already a legal requirement for developers and grounds maintenance specialists in England where you’re required to present a robust BNG strategy to gain planning approval or obtain permits.

4. Habitat Restoration

Developers and grounds maintenance specialists could be required to restore habitats and natural environments under Biodiversity Net Gain rules. This may involve creating new habitats rich with biodiversity or restoring ecosystems that have perished over time. Either way, BNG must improve the ecological value of any site ready for development or already under development.

How Do You Measure Biodiversity Net Gain?

By law, developers and landowners must deliver a BNG of 10% or more. To monitor this, biodiversity is measured in standardised biodiversity units of a specific site according to size, quality, location, and type.

Bad development can lead to the loss of biodiversity units, though units can also be generated through environmental work to create and improve habitats.

The official metric used by the UK Government to measure biodiversity is:

• The number of units contained in a habitat before development starts.
• The number of units needed to replace lost or damaged habitats and to achieve a minimum of 10% BNG.

Developers and landowners are required to use the government’s statutory biodiversity metric tool when calculating the number of biodiversity units present in an existing habitat and to work out any necessary habitat enhancements that may be required.

Who is Responsible for Delivering Biodiversity Net Gain?

The land manager holds legal responsibility for creating, protecting, and enhancing natural habitats set aside for development. They are also responsible for managing that habitat for at least 30 years to achieve their BNG target.

A land manager is someone who makes significant on-site gains or sells off-site gains on a site they own. Where a developer buys off-site units, they are effectively paying a land manager to tend the land for 30 years to meet their BNG commitment.

Who Will Be Affected by Biodiversity Net Gain Rules?

The following groups must understand BNG rules to avoid potential fines and penalties for ignoring their legal obligations. They include:

• Large-scale developments such as shopping centres, schools, offices, and public buildings.
• Small development sites from April 2024.
• Infrastructure projects of national importance from November 2025 such as railway tunnels, bridges, and sporting arenas.
• Land managers looking to sell an area of land for development.
• Local planning authorities (LPA).

Consulting with Local Planning Authorities is recommended as early as possible in the planning process to allow developers time to increase biodiversity by at least 10%. However, not all development sites will be appropriately located to implement this increase. In this scenario, developers may need to alter their plans or create offsite mitigation schemes in a bid to secure planning permission.

As regulations do not specify that BNG must occur on the same geographical site set for development, it gives both developers and landowners more flexibility around the new legislation.

Who is Exempt from Biodiversity Net Gain Rules?

Not all developments or land managers have to abide by BNG rules. Some developments are exempt from the regulations. These include small sites such as residential developments of between 1 and 9 dwellings or where the site area is less than 0-5 hectares, developments below the threshold where work impacts less than 25 square metres of habitat or 5 metres of hedgerow, or householders seeking planning permission for small projects like home extensions or conservatories.

If you’re unsure whether you’re development is exempt from mandatory BNG regulations, there is an online UK Government guide that lists all exempt cases.

How do you Achieve Biodiversity Net Gain?

Through careful site selection and empathetic planning, developers can reduce any negative impact on biodiversity or avoid it completely. Rather, developers and landowners can deliver a minimum of 10% BNG in line with the government’s statutory biodiversity metric.

Put simply, developers and landowners can meet their 10% BNG targets in 3 ways:

• By restoring, protecting, and improving biodiversity on-site. This includes all land that falls within the red line boundary of the development site.
• A mixture of on-site and off-site BNG solutions for cases where developers can only achieve part of their BNG obligations on-site. Here, developers can introduce BNG on their own land outside the development site or buy off-side biodiversity units elsewhere.
• Where BNG cannot be achieved on-site or off-site, developers must buy statutory biodiversity credits from the government who will use the revenue to create diverse natural habitats in other appropriate locations.

What is an Example of Biodiversity Net Gain in Practice?

If a developer cuts down trees on a site, they must mitigate its impact on the natural environment in addition to delivering 10% BNG.

This would mean conducting a habitat survey before development starts and using the statutory biodiversity metric. This will provide viable options they could use to make up for the tree loss and other actions they could take to achieve 10% BNG.

If, however, 10% BNG cannot be achieved on-site, they must buy off-side units. If they still fall short of their legal obligations, they’ll have to purchase statutory biodiversity credits from the government.

Unsure How to Achieve Biodiversity Net Gain? Need Help?

At Grounds Care Group, we have expert knowledge of biodiversity net gain best practices to ensure your development plans meet government regulations. From landscape maintenance to tree surgery to grounds technology, contact Grounds Care Group today.