England’s planning landscape has undergone a significant transformation with the mandatory implementation of Biodiversity Net Gain (BNG) for major developments from January 2024, followed by small sites in April 2024. This new statutory requirement, stemming from the Environment Act 2021, dictates that all new developments must deliver at least a 10% measurable improvement for biodiversity compared to their pre-development state, aiming to halt nature’s decline and foster environmental recovery across the country.
Context: A Paradigm Shift in Planning Policy
The introduction of BNG represents a fundamental shift in how development interacts with the natural environment. Historically, planning policy often focused on mitigating harm to biodiversity; BNG goes further by mandating a net positive impact. This policy emerges against a backdrop of alarming biodiversity loss in the UK, one of the most nature-depleted countries globally, making nature recovery a critical national priority.
The concept of BNG was first trialled in various pilot projects, demonstrating its viability and informing the detailed guidance now in place. Its formal inclusion in the Environment Act 2021 underscored the government’s commitment to embedding environmental considerations deeper into the planning system. After several delays to allow developers and local authorities to prepare, the phased rollout signifies a pivotal moment for ecological restoration alongside economic growth.
The 10% Net Gain Requirement Explained
At the core of BNG is the ‘10% net gain’ principle, which requires developers to assess the biodiversity value of a site before development using the standardised Defra Biodiversity Metric. This metric quantifies habitats into ‘biodiversity units,’ allowing for a clear comparison of a site’s ecological value pre- and post-development. Developers must then demonstrate how their plans will achieve a 10% increase in these units, ensuring a tangible uplift in biodiversity.
Achieving this gain can be complex. The hierarchy of delivery prioritises on-site enhancements, such as creating new habitats within the development boundary. Where on-site delivery is not feasible or sufficient, developers can utilise off-site solutions, either by purchasing biodiversity units from ‘habitat banks’ – land managed specifically for biodiversity gain – or, as a last resort, buying statutory biodiversity credits from the government. All BNG enhancements, whether on-site or off-site, must be secured for at least 30 years through legal agreements, ensuring long-term ecological benefits.
Local planning authorities play a crucial role, responsible for approving BNG plans and ensuring compliance. This necessitates a robust understanding of ecological principles and the Defra Metric, alongside effective monitoring and enforcement mechanisms.
Implications for Key Stakeholders
The implementation of BNG carries significant implications across the development sector and public services.
For developers, BNG introduces new costs and complexities into the planning process. Early engagement with ecological consultants is now paramount to assess sites, design BNG strategies, and navigate the metric. This may impact project timelines and budgets, requiring a strategic approach to land acquisition and design. However, it also presents an opportunity to enhance the sustainability credentials of developments and potentially increase property value through integrated green infrastructure.
Local authorities face increased workload and the need for enhanced ecological expertise. They must ensure BNG plans are robust, monitor compliance over the 30-year period, and potentially manage a local market for biodiversity units. This will require investment in training and resources to effectively discharge their new statutory duties and ensure accountability and oversight.
Landowners are presented with new avenues for income generation by creating and managing habitat banks, selling biodiversity units to developers. This could incentivise land management practices that prioritise nature, contributing to wider landscape-scale nature recovery initiatives.
Expert Perspectives and Broader Impact
Environmental organisations largely welcome BNG as a critical step towards reversing biodiversity decline, though some express concerns regarding its implementation and potential for ‘greenwashing.’ The government’s aspiration is for BNG to deliver significant ecological benefits, contributing to targets outlined in the 25 Year Environment Plan.
Data from Natural England and Defra indicates the potential for thousands of hectares of new or restored habitats across England. However, the success hinges on rigorous enforcement, transparency in the biodiversity unit market, and robust long-term monitoring. Industry bodies like the Chartered Institute of Ecology and Environmental Management (CIEEM) highlight the urgent need for skilled ecologists to meet the increased demand for BNG assessments and advice.
Economically, BNG could stimulate a ‘green economy’ within the land management and ecological consultancy sectors, creating new jobs and investment opportunities. It also encourages innovative approaches to sustainable development, potentially leading to more resilient and attractive communities.
What to Watch Next
The coming months will be crucial as the BNG framework fully beds in, particularly with its extension to small sites in April 2024. Attention will focus on how effectively local authorities manage the increased demand for approvals and monitoring, and the development of a transparent and equitable market for biodiversity units and credits. The balance between delivering much-needed housing and achieving genuine ecological uplift will be a key area of scrutiny. Furthermore, the long-term effectiveness of the 30-year maintenance requirement will determine if BNG truly delivers lasting benefits for nature. Observers will also be keen to see if the BNG principle is adopted or adapted in the devolved nations, potentially leading to a more consistent approach to nature recovery across the UK.
Source: Department for Environment, Food & Rural Affairs (Defra), Natural England, Environment Act 2021.
Published by Notherelong.
