In February 2023, the government responded to the Biodiversity Net Gain (BNG) consultation which ran in January 2022.
The BNG policy is a step forward in environmental conservation, incorporating a mandatory net gain of 10% towards the nation’s biodiversity, typically through habitat creation, restoration and enhancement. This objective is required to obtain planning permission. Without proving they can result in the 10% gain after 30 years either on-site or off-site, factoring in the biodiversity lost in development, the developers cannot build. It follows the mitigation hierarchy, is currently mandatory for major developments, and will be mandatory for smaller sites from April 2024.
The consultation and its response encompass a range of development types including schemes from the Town & Country Planning Act (TCPA), and Nationally Significant Infrastructure Projects (NSIPs). This is to make sure that all developments can align with the policy, and that all can follow the structured guidance to aid their navigation through the new legislation.
This post explores the consultation document, the event and the subsequent government response, examining the proposed implementation of mandatory BNG across different development categories, and the implications this brings to the everyday lives of many in the UK.
What was the Biodiversity Net Gain Consultation?
Part of the Environment Act 2021, the BNG policy was carefully cultivated over many years until it was ready to be a mandated legislation. A central part of its development was the BNG (Biodiversity Net Gain) consultation, which asked questions about how BNG will be applied to Town and Country Planning Act development and Project NSIPs (Nationally Significant Infrastructure Projects). It answers key questions and creates appropriate public discourse regarding the BNG initiative.
Organised by Defra, the consultation was held from January 11th to April 5th 2022. It took place online, which enabled a wide range of stakeholders and important parties to participate. They gathered 590 responses.
The consultation covered many key aspects. It proposed the 10% mandatory gain compared to its pre-development baseline, the technical details of measuring biodiversity, the scope of the applicable projects, and the mechanisms that will enable the measurement and monitoring of the gains over the 30 year period.
It delved into the role of Local Planning Authorities (LPAs) and their increase of work in the planning system, as well as the metrics instrumental to the condition assessment required at multiple stages of the BNG processes.
The consultation alleviates concerns from the new legislation and ensures hefty expert insight from the environmental, planning, and development sectors to fine-tune every detail of the policy in order for it to be effective and workable.
The Government’s’ Consultation Response
Town and Country Planning Act 1990 (TCPA) Requirement
The Country Planning Act defines the scope of BNG requirements for the development process. The response outlines exemptions under the Environment Act 2021, explaining that key exemptions include developments impacting habitats smaller than the ‘de minimis’ threshold (25 square metres or 5 metres for linear habitats like hedgerows), householder applications, biodiversity gain sites enhancing habitats for wildlife, and small scale self-build and custom housebuilding projects.
These exemptions are designed to prevent the policy from being overly burdensome while still encouraging biodiversity enhancements where possible.
For developments not covered by these exemptions, including previously developed land and change of use applications, the biodiversity metric—a tool developed to quantify impacts and gains on biodiversity—plays a crucial role. It allows for certain activities, like temporary impacts that can be restored within two years, to be excluded from BNG calculations.
Existing sealed surfaces are assigned a zero score, effectively exempting them from the gain requirement.
The government finally emphasises the opportunity for exempt developments to contribute to biodiversity enhancements through planning policy, indicating a comprehensive approach to integrating BNG into the TCPA framework.
BNG for Different Development Types
In the consultation response, the application of BNG was considered within a range of different development types, to cover all bases and explore specific details of different contexts.
For phased developments or those that might be subject to subsequent applications, a detailed BNG plan is required. This should explain each phase to address concerns about ‘front-loading’ biodiversity gains. The efficient process should be facilitated by secondary guidance and legislation.
Section 73 of the 1990 TCPA applications may affect biodiversity value, and in this case, an updated BNG plan may be required. Modifications should always align with BNG requirements.
A new metric is brought out for smaller sites with the support of digital tools and training. In consideration of LPA’s preparation needs, the response also announced that smaller sites will not require BNG until April 2024.
Nationally Significant Infrastructure Projects (NSIPs) will follow a consistent BNG approach without broad exemptions, except for irreplaceable habitats. The government goes on to release a draft biodiversity gain statement for NSIPs, with a commencement date no later than November 2025, encouraging early voluntary adoption.
The government seeks to ensure BNG’s integration into planning processes across development types, emphasising the use of digital tools, guidance, and policy adjustments to address specific challenges, including those related to marine infrastructure.
How Mandatory BNG Will Work for TCPA Development
The government’s response to implementing BNG under the TCPA 1990 explores new strategies and adjustments thanks to the consultation.
Examples of this are simplifying requirements, especially for phased projects and mineral sites in order to maintain flexibility in achieving on-site gains.
The government set a 30 year period for securing BNG sites, potentially allowing post-agreement enhancements to foster long-term patterns of conservation.
BNG Units should be an option for all landowners, and it is emphasised that LPAs cannot express preference unless clear ecological justifications. Importantly, if a developer is able to exceed BNG objectives they may sell the excess site gains.
Our BNG Marketplace is a perfect example of this.
For larger conservation projects, parties may consider habitat banking with strategic habitat creation. This is a powerful biodiversity offsetting scheme, parcelling together vast expanses of land, at times with protected species and habitats, to protect and enhance the entire space.
Biodiversity sites will be recorded on the Biodiversity Gain Site register, managed by Natural England, which went live recently. It is a public record to allow parties, such as developers, to quickly verify BNG sites. It ensures transparency and accountability without duplicating local planning authority data.
Considerations of BNG as a new burden—a policy which increases the cost of local authorities’ services—resulted in new burdens funding in support of the transition of an increased LPA workload.
Key Points from the Consultation Response
Here are the key takeaways from the UK government’s response to Defra’s consultation:
- Mandatory BNG will take place for NSIPs in November 2025 and TCPA schemes in November 2023, and small sites will have to follow the policy from April 2024.
- Exemptions will include smaller habitats, householder applications, biodiversity gain sites and custom builds.
- Other exemptions include irreplaceable habitats, which will be sculpted out later
- At this stage, compulsory purchase is being considered for BNG, but only as a last resort
- Future Biodiversity Net Gain (BNG) regulations and guidance will detail the process, including the use of BNG Statements and biodiversity gain plans within planning applications.
- A market will enable landowners to sell biodiversity units, with habitat banks facilitating larger, strategic conservation efforts. A new biodiversity gain site register, managed by Natural England, will track offsite biodiversity gains.
- Until the biodiversity units market matures, statutory biodiversity credits will be available, intended as a temporary measure.
- No exemptions for previously developed land, temporary applications, change of use applications, and developments affected by their location in sensitive areas, indicating a broad application of BNG requirements.
- Irreplaceable habitats are excluded from the BNG objective, requiring appropriate compensation instead. This category will be clearly defined through further consultation.
- The BNG approach for NSIPs will align with that for TCPA schemes, emphasising consistency in scope, percentage requirements, and exemptions.
- While not elaborated on, the government suggests that compulsory purchase may be considered as a last resort for delivering BNG.
From 590 responses from experts in all appropriate sectors, Defra was able to carve an appropriate response to the consultation and aid the delivery of a thorough policy.