Understanding Biodiversity Net Gain

A Cogeo Insight into the Statutory Requirement for BNG

Welcome to our latest Cogeo Insight article, exploring the recent announcement that biodiversity net gain has become a statutory requirement for developments in England as of 12th February 2024. Here, we delve into the pivotal subject of Biodiversity Net Gain (BNG), exploring why BNG has transitioned from a best practice aspiration to a statutory requirement for development planning. You may know what BNG is and its importance. However, throughout this insightful article, we'll explain the essence of BNG, highlight the legislative changes, and offer practical guidance for developers navigating this new landscape. Through our expertise in planning and environmental management, we strive to provide clarity and support to our clients and the broader development community, ensuring sustainable and biodiversity-positive outcomes are central to all projects.

Biodiversity Net Gain At a Glance

As an area of planning development that will continue to evolve, gaining insight and integrating BNG into your development planning strategy is now essential. We've also prepared an At a Glance reference document which sets out the mitigation hierarchy when considering a project and you can download that for future reference here.

Key Insight and Article Takeaways

Biodiversity Net Gain: With BNG now a statutory requirement, it’s crucial for developments to enhance natural environments. Discover what this means for your projects.
Understanding the Metrics: We'll detail the BNG metrics, showing how understanding and incorporating them into your planning can enhance biodiversity and strengthen your development applications.
Phased Approach: Statutory BNG will roll out in phases, impacting developments of all sizes across the UK. We’ll help you navigate the timelines.
Integrating as a Developer: Integrating BNG from the early stages of project planning is essential for developers. Our guidance ensures your processes align with sector needs and comply with legislation, benefiting your projects.
Taking practical steps: Achieving BNG can be straightforward with the right approach. Incorporating habitat restoration, sustainable design, and strategic environmental planning into your projects enhances your planning applications and contributes to environmental sustainability. Cogeo is ready to support you every step of the way.

What is Biodiversity Net Gain?

Understanding the Foundations

Biodiversity Net Gain (BNG) represents a transformative shift in environmental conservation, particularly within development planning. At its core, BNG is not merely a concept but a mandated practice whereby developers must ensure their projects culminate in a net positive impact on biodiversity. This practice means that the work should improve the quality and quantity of natural habitats compared to pre-development conditions.

The ethos behind BNG is rooted in acknowledging that while development is necessary for societal growth, it should not come at the expense of our natural environment. Instead, development should contribute positively, enhancing local ecosystems and promoting a richer, more diverse natural world. This approach aligns with broader sustainability goals, aiming to reconcile human activities with the vital need to preserve and enhance nature.

Legislative Background and Important Dates

The transition of Biodiversity Net Gain from a recommended guideline to a statutory obligation in England marks a significant milestone in environmental legislation. The Environment Act 2021 is a primary driver in formalising the BNG requirement in development projects.

The legislation mandates a minimum 10% increase in biodiversity value from pre-development baselines. This requirement ensures that projects not only aim to prevent harm to the existing natural environment but actively improve it, setting a new standard for sustainable development.

Important dates regarding the statutory rollout of BNG are critical for developers, planners, and environmental consultants alike:

12th February 2024: This date marked the initial phase where all major planning applications submitted in England must demonstrate how they will achieve BNG. 'Major' developments are typically defined as residential developments of 10 or more homes or other developments where the site area exceeds 0.5 hectares.
2nd April 2024:The requirement extends to 'small sites', which include residential developments of fewer than ten dwellings, commercial developments with less than 1,000 square meters of floor space, or any site under one hectare. This broadening of the scope ensures that developers, planners, and environmental consultants consider and integrate BNG principles across a broader range of development projects.
End of 2025: By this time, the industry expects BNG to become a statutory requirement for nationally significant infrastructure projects, including large-scale developments such as new highways, energy plants, and other major infrastructure projects that significantly impact the land and local ecosystems.

These phased timelines provide a framework for the sector to adapt and prepare for the full integration of BNG into the planning process. It is crucial for all parties involved in development to be aware of these dates and to start incorporating BNG principles into their projects as early as possible. Early adoption will ensure compliance and contribute positively to the UK's biodiversity targets. With these dates in mind, we encourage current and prospective clients to engage with the Cogeo team for BNG guidance, advice and support.

BNG and the rest of the UK?

The mandatory legislation currently applies only in England, with the Welsh Government in a draft policy and consultation phase, with proposals on any bill to follow.

Scotland is taking a different approach to biodiversity than England, focusing on 'enhancement' rather than imposing a legal requirement for biodiversity net gain. The Scottish government has integrated biodiversity gain into the National Planning Framework 4 (NPF4) through NPF policy 3: Biodiversity. This policy differentiates between national, major, and EIA development and local development, each requiring specific conservation and enhancement measures for supporting biodiversity, ensuring developments are better post-intervention without setting a national minimum enhancement level. The Scottish Government published Draft Planning Guidance on Biodiversity in November 2023 to clarify understanding of NPF4 Policy 3 as well as announcing that NatureScot will be developing a metric to support the delivery of Policy 3, in line with the metric-based approach in England.

The Scottish strategy offers a more discretionary and flexible approach, allowing local planning authorities to decide on the appropriate level of biodiversity enhancement without adhering to a fixed biodiversity metric model or a national minimum standard. Unlike England, Scotland is not planning to implement a biodiversity credit system. It has no fixed criteria for biodiversity enhancement, leading to potential uncertainties regarding developers' expected level of biodiversity improvements. This approach aims for proportionate measures in local developments to enhance biodiversity, with room for off-site enhancements, though specifics remain open to the planning authority's interpretation.

There are currently no plans or proposals to legislate on BNG in Northern Ireland, but planning will encourage biodiversity with all planning proposals.

Understanding BNG Metrics

Delivering Tangible Conservation Efforts

The Biodiversity Net Gain (BNG) metric is a critical element for sustainable development and enables the comprehensive evaluation and quantification of a site's biodiversity value before and after a development project. It's more than just a measure; it bridges current practices and the desired positive outcomes for our natural environment.

At the heart of the BNG metric lies its ability to calculate 'biodiversity units' - a concept central to understanding the ecological footprint of all project developments. These units offer a standardised measure of the quality and extent of different habitats, providing a clear baseline to plan site improvements. The process compares this baseline to the anticipated post-development biodiversity units, thus determining the 'net change' in biodiversity resulting from the project.

There are three primary types of ecological features, each contributing uniquely to the overall biodiversity of an area associated with the metric:

Habitat Units: This category encompasses the varied types of terrestrial habitats found within a project site, from lush grasslands to dense woodlands. These units are the building blocks of terrestrial ecosystems, supporting diverse species and ecological functions. By evaluating habitat units, developers, planners and environmental consultants can gauge the impact of projects on these crucial areas and strategise on enhancing or restoring them as part of their BNG efforts.
Hedgerow Units: Hedgerows, tree lines, and other linear features act as vital corridors for wildlife, facilitating movement and genetic exchange between isolated habitats. In development, preserving and enhancing these linear habitats can significantly contribute to ecological connectivity and biodiversity.
Watercourse Units: The final piece of the metric focuses on aquatic environments within the project area, such as ditches, streams, and canals. Watercourses are critical for biodiversity, supporting a variety of aquatic and semi-aquatic species. They also play essential roles in hydrological processes and ecosystem services. By assessing watercourse units, the BNG metric ensures that developments account for the health and integrity of aquatic ecosystems.

The BNG metric empowers developers to make informed, responsible decisions, working with planning and environmental partners by meticulously assessing habitat, hedgerow, and watercourse units. Quantifying ecological values and impacts paves the way for projects that minimise harm and actively enhance local and regional biodiversity. Therefore, this process is not just a regulatory requirement but a step towards a more sustainable and ecologically mindful approach to development, one that Cogeo has been championing for many years.

Why the Statutory Requirement?

The Driving Forces Behind the Legislation

The transition of BNG from a voluntary to a statutory requirement underscores a growing recognition of the critical need to protect and enhance our natural habitats. This legislative shift, spearheaded by the UK government, aims to stem the tide of biodiversity loss and foster sustainable development practices harmonising with nature.

Understanding BNG Metrics

The Tool for Tangible Conservation Efforts

The BNG metric is a quantifiable tool designed to assess the impact of development projects on biodiversity. It encompasses three main unit types: habitat, hedgerow, and watercourse units. This metric aids developers in understanding their environmental footprint and guides them in making informed decisions to achieve positive ecological outcomes.

Implications for New Developments

Navigating the New Norms

For developers, the BNG introduction mandates a strategic re-evaluation of project planning and execution. Focusing on habitat creation, enhancement, and preservation ensures developments contribute positively to local biodiversity and benefit all stakeholders. Some may consider BNG another hurdle to address for successful planning approval. However, addressing, appropriately managing and providing BNG evidence adds value to pre-project development and the future, making it more favourable for planning officers and committees.

The Impact on the Planning Application Process

Adapting to Change

The phased introduction of statutory BNG will reshape the planning application landscape. From major projects to small sites, all developers must now integrate biodiversity improvements from the inception of their planning applications.

A Final Word from Anna Balls, Lead Project Consultant at Cogeo Planning and Environmental Services Ltd.

“Biodiversity Net Gain represents a significant step forward in sustainable development. For our clients, our message is to work with the constraints of your site as part of the project design. Early engagement for walkover surveys ensures all priority features and habitats are understood to gauge the impact and mitigation options available. Our experience of the BNG assessment metric is that it has been a relatively blunt tool for smaller sites, so we welcome a renewed focus on keeping the level of assessment and mitigation proportionate to the impact of the development, as well as the opportunity to look at off-site enhancement for particularly constrained sites.

Our message for clients is relatively simple; Follow the mitigation hierarchy when considering a project: