The UK government has published two pivotal consultations that could redefine how BNG is delivered across England. These proposals are particularly relevant to those involved in planning, development land, and infrastructure projects, and they signal a major step forward in embedding nature-positive principles into the built environment.
Two consultations, one goal: A Smarter approach to BNG
The first consultation focuses on BNG for Nationally Significant Infrastructure Projects (NSIPs), proposing how BNG should be applied to large-scale infrastructure schemes. The second seeks to improve the implementation of BNG for minor, medium, and brownfield developments, with a particular emphasis on easing the burden for SME developers.
Alongside these, a working paper explores how BNG might be extended to a new category of medium-sized developments, hinting at future changes to the planning system.
Both consultations are open for comment until 24 July 2025.
What these consultations mean for our clients
To help our clients navigate these changes, we spoke with specialists across our business:
- Angela Brooks, Planning Partner
- Luke Brafield, Development Agency Partner
- Mark Gilkes, Infrastructure Consultancy Partner
- Tom Beeley & Christy Wells, Natural Capital Experts
Their insights help unpack what these proposals mean for the planning system, landowners, developers, and infrastructure providers and how our clients can best prepare for the changes ahead.
Infrastructure: Clarity needed for long-term projects
“Discussions, particularly with linear NSIP promoters reveal a mixed response, shaped by project-specific factors such as timescales, promoters, and scale. Some welcome the delay, seeing it as a potential opportunity to submit applications without the formal BNG requirement, thereby avoiding the complexities of delivery. Others are frustrated, having invested significant time and effort preparing for a challenge that may no longer be necessary.
“Many are already voluntarily committed, driven by internal targets and a desire to leave a positive legacy. Yet almost all express frustration at the ongoing uncertainty, especially given that only in January was it confirmed that compulsory purchase powers could be used for BNG, and now the shifting goalposts may suggest further delay or even that it might never be required.”
Planning: A chance to refine and rebalance
"The Government remains committed to delivering 1.5 million homes within its five-year term, but the path to achieving this goal is not without challenges, particularly for smaller developers navigating the complexities of BNG requirements. The costs associated with baseline assessments, post-development schemes, and Section 106 agreements are disproportionately impacting the viability of minor developments.
“Encouragingly, the Government has responded by launching a consultation that considers new development categories and potential exemptions. Notably, minor residential developments, those with fewer than 10 homes, may be exempt from BNG, a move welcomed by many as a step toward proportionality. Additionally, the Small Sites Metric (SSM) may be extended to medium-sized developments to streamline assessments, while further technical refinements to the metric tools are also under review.
“Stakeholder feedback has highlighted the unique challenges of delivering BNG on brownfield sites, prompting the Government to explore more flexible habitat compensation options. Recognizing the strain on local planning authorities, particularly due to the scarcity of ecological expertise, a £10 million funding pledge has been made to support implementation and monitoring efforts."
Balancing BNG with housing delivery: A developer’s perspective
“The recent consultation on BNG is a welcome step forward, particularly as the current requirements have constrained the delivery of new homes in a number of areas. This has had a direct impact on the Government’s ambitious target of delivering 1.5 million homes over the current parliamentary term.
“One of the most pressing challenges lies in the disproportionate impact BNG has on smaller development sites. These are often brought forward by SME developers who lack the extensive resources available to larger PLC housebuilders impacting on their ability to find solutions. With limited land area, accommodating BNG becomes increasingly difficult, adding complexity and cost to already tight development margins.
“Brownfield sites, where development takes place on previously developed land face even greater hurdles. These sites usually already carry higher abnormal development costs related to ground conditions, drainage, highways, and utilities. The additional requirement to deliver BNG further undermines financial viability, potentially deterring investment in these much-needed regeneration projects.
“The financial burden of BNG is also highly variable. Based on recent experience, costs have ranged from over £11,000 to as much as £20,000 per dwelling, depending on the baseline ecological conditions and the type of biodiversity enhancements required. These costs are not currently being reflected in the prices that housebuilders can command for new homes, creating a further squeeze on viability.
“Moreover, the requirement for BNG is reducing the proportion of land that can be developed for housing. Where developers previously worked on the basis of 60–70% developable area relative to gross site area, this has now dropped to 50–60%. This reduction not only affects the number of homes that can be delivered but also the overall efficiency of land use.
“It is important to emphasise that the development industry is not opposed to the principle of BNG. There is a clear recognition of the need to balance environmental enhancement with the delivery of new homes and the economic growth that development supports. However, for BNG to be successful and sustainable, it must be implemented in a way that is proportionate, viable, and supportive of the broader goals of housing delivery.”
Natural capital perspective
Tom and Christy offered a broader perspective: “The consultation on the application of BNG to NSIP projects starts to shed light on how BNG might apply to large scale infrastructure projects. Given the long-time scales involved in developing NSIP projects confirmation of how BNG will be applied is much needed.
“It indicates that implementation of BNG to these projects will be pushed back to Spring 2026 having previously been suggested it would be introduced from November 2025. It will be important for infrastructure providers to review and feedback on the proposals to ensure they are practical and workable to deliver for both nature and the economy within the infrastructure planning process.
“The review of the application of BNG to small sites comes just 15 months after BNG was introduced to the planning system in England. The review seeks to address some of the challenges that BNG raises for smaller scale development with concerns raised by some that BNG compliance is disproportionate to the impact of the development taking place hindering the delivery of homes and other forms of beneficial development.
“Whilst there have undoubtedly been challenges with delivery of BNG on small sites it should be noted that the BNG offsetting market remains in its relative infancy and is developing quickly to provide solutions to some of these challenges. Whilst amendments to BNG might be welcome to ease the burden on developments and ensure BNG remains practical and workable, there is a fine line to be trodden to ensure that this does not represent a backward step for nature. There are concerns that some of the options proposed go too far in removing the BNG objectives and may hinder the development of the emerging BNG market and investment into the wider natural capital sector more generally.
“It is positive to see government set out their commitment to BNG policy within the consultation and acknowledge the challenges delivering BNG on small and medium sized sites. This consultation will be relevant to anyone involved in the development of smaller scale sites be that housing, commercial or infrastructure and provides an opportunity to comment on amendments to the BNG regime. it is hoped that the government’s response is reflective of both the need to streamline development planning and encourage investment into nature recovery to reverse the decline in UK biodiversity.”