There is “doubt” about whether local authorities will be able to lead the implementation of rules around statutory biodiversity net gain (BNG), according to a report from the National Audit Office (NAO).
The requirement for developers to ensure a 10% biodiversity net gain (BNG) came into effect on 12 February 2024 for large schemes (over 1,000m2 for non-residential) and 2 April for smaller schemes.
The Department for Environment, Food & Rural Affairs (Defra) described the move as “world-leading” and said it would “deliver the government’s commitment to halt species decline by 2030”.
Natural England chair Tony Juniper said that the BNG legislation was “a key moment on our path to halting the decline of nature”.
However, there were already concerns about the strain it could have on local planning authorities in trying to ensure that developers followed this requirement and the NAO has now shed light on this.
In its report, which was commissioned by the Environmental Audit Committee, the NAO found that “Defra launched its policy before having all the elements in place that it needs to ensure statutory BNG is a success in the long term”.
It added: “Although [Defra] considered that the arrangements it had in place at launch were sufficient, it has a long way to go before it can be confident that damage to biodiversity through development will not be understated and that the benefits of biodiversity enhancements will actually be delivered.”
The report’s conclusion, in addition to acknowledging Defra had “accepted some significant risks to effectiveness”, said: “Local authorities manage many aspects of statutory BNG through the planning process, including ensuring compliance and enforcement.
“For now, there is doubt about whether local authorities will be able to discharge these duties effectively.
“In addition, it is not clear whether Defra will have sufficiently granular monitoring data to assess policy performance.
“Without these, Defra will not have assurance that its statutory BNG policy is delivering biodiversity outcomes and value for money for taxpayers.”
It made a series of recommendations aimed at Defra.
The recommendations included requesting that Defra “establish arrangements to understand and respond to system-wide risks and opportunities” and asked it to monitor the private market for biodiversity units to ensure it is growing “at the pace and scale it needs to in order to provide developers with the range of habitat types they require”.
It also emphasised that Defra must support “local delivery” and dedicated a third of its recommendations to this area, including ensuring that “local authorities have sufficient and timely funding certainty to allow longer-term planning”.
Further, it said Defra must “determine how it will monitor the effectiveness of compliance and enforcement by local authorities and responsible bodies, to give Defra adequate assurance
that these organisations are complying with their statutory BNG obligations”.
Engineering firms react
Consultant engineering firms warned about “significant uncertainty” around what mandatory BNG would mean for Nationally Significant Infrastructure Projects, and said local authorities face “resourcing and funding challenges” regarding assessment of applications and monitoring.
Jacobs senior associate director, biodiversity net gain lead (ecology) Sally Fraser said: “We welcome this report and its recommendations relating to managing risks as statutory BNG embeds as business as usual.
“For Nationally Significant Infrastructure Projects (NSIPs), where BNG is not yet mandatory, we’re seeing the imminent requirement resulting in earlier engagement on projects in respect of embedding biodiversity into design.
“This should lead to better biodiversity outcomes. However, there remains significant uncertainty around what mandatory BNG will look like for NSIPs and when it will come into force, which is impacting project confidence when it comes to decision making around BNG assessment and delivery.”
Aecom technical director – BNG lead Lewis Deacon said: “Aecom has had a dedicated BNG team since 2017 and has worked closely with clients to advise them and support their delivery.
“BNG has only recently become mandatory for planning applications, so not every organisation will have engaged on BNG to the extent that is now required and we expect it will take a bit of time for them to get up to speed.
“We know from working with local authorities across the UK that for some there are resourcing and funding challenges in the assessment of applications and the long-term monitoring requirements of developments.
“The statutory biodiversity credit approach is in its infancy and we’re keen to see how the funds generated will be deployed for nature.
“We’re actively engaging with other consultancies, law firms and planners to discuss how we can drive industry delivery on BNG.”
Local government
The LGA (Local Government Association) which represents local authorities echoed engineering firms and said “it is important that councils are properly funded”.
LGA environment spokesperson Darren Rodwell said: “Biodiversity net gain has fantastic potential for local communities and the environment.
“It is important that councils are properly funded and that the government quickly put in place measures to ensure the land is available for BNG off-site, for instance by allowing BNG on council-owned land in the short-term.
“We want to work with government to ensure that councils have the right tools and resources to implement biodiversity net gain as effectively as possible.”
Green groups
Environmental bodies called on the government to increase the minimum thresholds for BNG and agreed that a lack of support for local authorities is a risk to BNG implementation.
The Chartered Institute of Ecology and Environmental Management (CIEEM) head of professional practice Mark Nason said: “The NAO report highlights as a key risk, the need for local authorities to have sufficient access to ecologists to assess developers’ plans, and the ability (in terms of capacity or expertise) to take on legal responsibilities for monitoring and enforcing BNG.
“Some of the most important work that CIEEM is doing as a professional body is to support the capacity building necessary to help our sector rise to the challenge of implementing effective nature recovery.
“We welcome sustained government focus on both the activities to protect and restore nature, and to support and develop the skills and capacity required to deliver BNG.”
The Wildlife Trusts head of land use planning Becky Pullinger says: “Following so much delay and uncertainty, the implementation of Biodiversity Net Gain (BNG) finally got the ball rolling for both nature’s recovery and home building.
“However, many factors underpin the success of the scheme, such as the ecological expertise of local authorities, and the percentage requirement of the scheme itself.
“We encourage government to ensure its guidance supports local authorities and housebuilders to go above and beyond the bare-bones requirements of BNG: a 10% net gain will barely ensure no net loss of nature, whereas 20% could open the door for BNG to increase its contribution to national biodiversity targets and create a healthier and wilder future.
“The Wildlife Trusts collectively have over 20 BNG habitat banks delivering a Gold Standard BNG, working with local communities to create and restore the right habitats in the right places and ensuring the positive outcomes for people and nature are secured in perpetuity.”
Parliament and government
The NAO said it produced the report “in response to a request from the Environmental Audit Committee to contribute to its inquiry into the role of natural capital in the green economy”.
Environmental Audit Committee chair Philip Dunne said: “In recent years, the UK has seen a marked decline in biodiversity. Rising to this challenge, in February the Government became the first in the world to enshrine a national legal requirement for Biodiversity Net Gain – ensuring developers increase biodiversity by ten per cent compared to what existed before.
“Today’s report from the National Audit Office, commissioned by the Environmental Audit Committee, highlights the bold ambition of this biodiversity policy and notes areas for further work.
“The report finds that the government has some way to go before it can be confident that benefits of the policy to biodiversity will be delivered as intended. But it is never easy to develop new world-leading laws; I do not doubt the commitment this Government has to match its ambition with the hard work required to deliver across this complicated and novel landscape.
“I welcome today’s report and am grateful to the NAO for its nuanced analysis of a complex policy. These findings will make a valuable contribution to our ongoing inquiry into the role of natural capital in the green economy, and to our evidence session with the EFRA Secretary of State in June.”
A Defra spokesperson said: “Biodiversity net gain will ensure that new developments work for both wildlife and people.
“A mandatory 10% gain is estimated to create or secure areas of habitat the size of Bromley borough every year; it will drive further action to reverse the decline in nature and help meet our target for everyone to live within a 15-minute walk of a green space or water.
“We have carefully considered the recommendations of the report and they will inform our approach as we continue to work with developers, land managers and local authorities to ensure the smooth implementation of biodiversity net gain which strikes the right balance and delivers positive outcomes for nature.”
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