What is Biodiversity Net Gain and what do developers need to do about it?
With the introduction of the Environment Act 2021, property development has entered a new era with mandatory Biodiversity Net Gain (BNG) requirements. So, what is biodiversity net gain, and who will it affect? Property development solicitor and specialist, Lauren Dixon, explains:
What is Biodiversity Net Gain?
Since February 2024, Biodiversity Net Gain has been a mandatory requirement on all new developments in England to ensure that the natural environment is left in a measurably better state than before the development.
Developers must ensure that BNG is not just preserved, but enhanced, as, under the new regulations, developers need to achieve a minimum increase of 10% in biodiversity value, which is sustained for at least 30 years (compared to biodiversity value prior to the development).
The idea behind this is that biodiverse ecosystems on development sites will positively impact local communities and help reduce greenhouse gas emissions by working towards mitigating climate change.
Who will it affect?
In England, BNG is mandatory under Schedule 7A of the Town and Country Planning Act 1990 (as inserted by Schedule 14 of the Environment Act 2021).
These new rules will need to be understood by:
- Developers of major developments
- Developers who work on small sites
- Land managers wanting to sell in the BNG market
- Local planning authorities
- Developers of nationally significant infrastructure projects from November 2025
What do developers need to do?
Prior to starting development projects and plans, it is important that developers assess the existing biodiversity value of the site. By conducting surveys, this information is used to assign a biodiversity score.
There is a statutory biodiversity metric tool (used by ecologists) which is a universal tool to calculate the value of habitats. Property developers can utilise this tool to calculate how many biodiversity units the development needs in order to meet the required 10% net gain.
As part of the planning process for the development, the developer will need to create a biodiversity gain plan, which details how the development will achieve biodiversity net gain. This will then be submitted to the local authority, where they will have eight weeks to review the plan to ensure it aligns with local and national biodiversity policies.
Once approved, this will form part of the conditions in the planning permission. The plan will need to be approved and implemented across the development.
How can developers achieve biodiversity net gain?
Developers can achieve BNG through the biodiversity gain hierarchy. There are three ways a developer can achieve BNG. Developers can combine all three options, but they must follow them in the order below.
- Creating biodiversity on-site within the boundaries of the development;
- They can also offset biodiversity gains on their own land outside the development site or buy off-site biodiversity units. This can be habitat banks with public and private landowners.
- If the above cannot be achieved, the developer must buy statutory biodiversity credits from the government. This is seen as a last resort, and these credits will be used to fund conservation efforts elsewhere
The purpose of this hierarchy is to avoid, mitigate or compensate for biodiversity losses, and the developer must ensure that biodiversity net gain is secured for a minimum of 30 years. This means that the BNG off-site needs to be secured for 30 years.
Overall, biodiversity net gain is a mandatory process which developers need to follow and implement into their development proposals. The outcome of this is to ensure that there will be better-quality places for wildlife to live and thrive and for people to enjoy.
If you are a developer looking to acquire development land, then GA’s specialist property development solicitors (working within the firm’s commercial property department) will be able to provide expert guidance and advice. Dealing with development sites across the South West and wider UK, GA Solicitors in Plymouth can provide expert and commercial guidance on your land acquisition or sale. We can also provide advice regarding options, overage and pre-emption agreements.
Call today on 01752 203500 or email me directly via lauren.dixon@GAsolicitors.com.
You can also read my guide detailing the top five things to consider when buying land for development.
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