UK Biodiversity Net Gain: the requirements, the context, and what businesses need to know

BNG: The requirements

Under the requirements, in-scope planning applications submitted on or after February 12, 2024 will not be able to secure planning permission without showing a biodiversity net gain. To demonstrate this, developers must provide a biodiversity gain plan, detailing how they intend to deliver a 10% net gain in biodiversity, which must be legally secured for a 30-year period (e.g., by way of planning conditions or conservation covenants). The central idea is to reverse the long-term decline in biodiversity by ensuring improvements to natural habitats are enduring rather than temporary.

In practice, this will involve developers carrying out a survey of the development site before construction and using the statutory metric provided by the Department for Environment, Food and Rural Affairs (DEFRA) to assess a site’s biodiversity value before the proposed development. There are then three possible methods developers can use to demonstrate the required 10% BNG, which must be applied in the following order:

1. first and foremost, creating biodiversity on-site;
2. (if developers cannot achieve all required BNG through 1) making biodiversity gains off-site, either by making gains on their own off-site land or by buying off-site biodiversity units on the market; and/ or
3. (if developers cannot achieve all required BNG through 1 or 2) buying statutory biodiversity credits from the government.

How does BNG fit in with global environmental frameworks?

First, BNG is aligned with the Kunming-Montreal Global Biodiversity Framework, agreed under the Convention on Biological Diversity—which the UK has signed and ratified—in 2022. The Framework sets out 2030 targets across a variety of sectors. Mandatory BNG is one of the UK’s principal tools for delivering those targets at a national level, including Target 4, which requires entities to “manage human-wildlife interactions to minimize human-wildlife conflict for coexistence”.

Second, BNG dovetails with private sector disclosure frameworks, including the Task Force on Nature-related Financial Disclosures (TNFD). When preparing TNFD disclosures and reports, developers will be able to rely on BNG data to supplement their nature-related disclosures, allowing the frameworks to operate in tandem.

BNG and UK competitiveness

The current Labour administration has a manifesto commitment to build 1.5 million new homes over the current parliament (i.e., by August 2029). The UK’s high construction costs stand in the way of this goal, with London, in particular, consistently ranking among the most expensive places to build globally. Since its introduction, BNG has been criticized for contributing to costs and delays in planning, with 94% of respondents in one industry survey stating that they had experienced planning delays due to BNG. Any material BNG-induced costs and delays to UK planning approvals necessarily dampen the attractiveness of the UK as a place to invest and build. These considerations contributed to DEFRA launching a consultation in May 2025 on the possibility of exempting “minor” developments (i.e., very small-scale residential or commercial developments) from the BNG requirement.

However, from a macro perspective, BNG is part of the UK positioning itself as an early mover on nature-positive regulation. If implemented pragmatically, BNG could underpin a competitive advantage in nature-based solutions, environmental consultancy services, data and verification—sectors in which the UK already has strengths. Conversely, if delivery is hampered by inconsistent local authority practice or unresolved interactions with housing and infrastructure objectives, the loss in predictability—both within a single planning application and across planning authorities—risks outweighing any gains to be made in these areas.

For overseas investors, the UK will increasingly be judged not simply on the existence of BNG requirements, but on regulatory certainty and clarity, speed of consenting and pricing levels of off-site biodiversity units (market-based) and statutory biodiversity credits (set by DEFRA).

What to expect over the short, medium, and long term

In the short term (6–12 months), businesses should stay on top of any changes to these requirements. Changes are anticipated in the near term, including bringing Nationally Significant Infrastructure Projects (NSIPs) into scope and DEFRA publishing its responses to consultations on (i) BNG for NSIPs, and (ii) exempting minor developments from the requirements (see above). Further, as the requirements bed in, some bottlenecks are to be expected around local authority capacity and the availability of off-site units.

In the medium term (12–18 months), focus is likely to shift from minimum compliance to optimization and integration. We may see BNG become an element of portfolio-level strategies for housebuilders, utilities, and other land-rich businesses. Rather than treating compliance for each site as an isolated tick-box exercise, businesses may seek to identify “core” nature recovery sites within their estate from which BNG units can be generated to support multiple projects. At the same time, where businesses set nature-positive performance targets, the data and governance built for BNG compliance may be leveraged to demonstrate progress more broadly.

Over the long term (18 months–5 years), BNG will become a “business as usual” planning requirement. Businesses that have invested early in internal capability and strategic land management will be better placed to navigate this landscape efficiently. Further, there is a plausible trajectory in which BNG acts as a stepping-stone towards broader nature-related regulation—for example, extending “net gain” principles to supply-chain-driven nature risk.