Biodiversity net gain (BNG) is an approach to development that aims to leave the natural environment in a measurably better state than it was beforehand. The UK Environment Act requires a minimum 10 per cent habitat gain, calculated using the government’s biodiversity metric. This can be delivered either on-site, or off-site through the purchase of biodiversity credits, and must be secured for at least 30 years.
Responding to the policy’s impact in its first year, Rob Hindle, Executive Director at Rural Solutions, said, “The process for mandatory BNG is bedding in across the planning system and in many instances is working well, and in many ways it’s remarkable how quickly and effectively it has been taken up.
“Different levels of ‘readiness’ across Local Planning Authorities remains a frustration for both applicants and emerging habitat bankers. The approval of a new group of responsible bodies which can ‘treat with’ via conversation covenants is welcome and will aid delivery, especially off-site.
“There is currently little transparency around the overall distribution of mandatory BNG on-site vs off-site to date, and the balance between demand and supply for off-site units. This lack of market insight is potentially unsettling for those that have invested heavily in the creation of habitat banks and may constrain future supply. It is also unhelpful for developers, particularly SMEs. Increased clarity around the emerging ‘off-site’ market (supply, demand, deals), and from policy makers would be very helpful.
“There is evidence of material delivery of mandatory BNG on-site, particularly for residential schemes. Where BNG has been provided on-site there is often a direct benefit in terms of the amount of land access to high quality green space within the new housing, clearly of benefit to people and local communities. It is very early to tell whether the creation of habitat as part of a housing scheme will deliver long term biodiversity gains equivalent to that which could have been delivered off site as part of a larger scheme. There are concerns arising around the long term ecological impacts of some on-site delivery, due in the main to uncertainty around longevity of management.”
Nick White is the Principal Advisor for Net Gain at Natural England, the body responsible for delivering the BNG policy.
Reflecting on whether BNG is making an ecological difference, he said, “BNG was never designed as a silver bullet to address the nature crisis in England, but it can and should play a role in local nature recovery. Habitats, take time to establish and only a small number of developments have reached the stage of needing to provide new onsite habitats or source offsite biodiversity units. The early signs are, however, encouraging. To date over 1200ha of land has been registered to provide offsite units to developers. This is land set aside for new and better habitats for wildlife that are unlikely to have existed without BNG.”
Kim Connor-Streich, CCO at Greenshank, believes the market is working. He said, “We have seen there being sufficient supply being developed, oversupply in some areas. The low use of statutory credits is a testament to this. The main limitation on the market working is due to LPAs not having the resources to process new schemes quickly. One of the core elements we need to see now is more visibility of what schemes are available and, importantly, what new schemes are being developed in each area. This will protect landowners from investing where there is an oversupplied market and allow developers to accurately forecast if they will be able to get local units. We hear the government rumbling about BNG being a ‘blocker’. This is simply not the case, and after so many years of creating BNG, it needs tweaks rather than an overhaul.”
White says that BNG is resulting in a paradigm shift in how development thinks about nature whilst delivering the houses and infrastructure the country needs.
He said, “In the past nature was all too often treated as an after-thought in construction. Sites were routinely levelled of anything blue or green. Such nature as was included or retained would often end up getting ‘value-engineered’ out of a scheme. Rarely was longer-term management and maintenance considered. BNG is flipping that because the earlier you consider nature, ideally at site selection/outline design, and the more of it you can retain the easier BNG is to achieve. BNG has significantly reinforced the mitigation hierarchy helping to create places to live and work that are alive with wildlife, boosting our health and well-being and creating attractive, resilient and liveable places.”
Connor-Streich says that there has been a drive by developers to deliver BNG onsite, in line with the mitigation hierarchy, but that this trend is unlikely to continue.
He said, “Firstly, a new report is due to be published highlighting the huge cost of onsite BNG delivery vs offsite, with onsite being way more expensive. Secondly, the maintenance of onsite BNG is a big problem. Most maintenance companies for new developments are unlikely to be well equipped to maintain habitats in the face of human disturbance pressures. We can see a scenario in the future where eNGOs are pointing at exhausted wildflower meadows in the middle of a housing estate and suggesting BNG has not delivered as promised, requiring legal redress.”
White acknowledged that there have been delivery challenges.
He said, “Mandatory BNG introduced a standardised new legal requirement, but the accompanying guidance was not always 100 per cent clear and the interpretation of the law and that guidance was, initially especially, quite variable. This was understandable. Nature is complex as too is the English planning system and legislation of any type always takes a while for professions to get to grips with. Although many SME developers have successfully met the BNG requirements others have found doing so more challenging. Work is ongoing in government, with input from Natural England and others, to address this.”
White concluded, “There are many positive takeaways from the first year of BNG but there have been some challenges too, as one might expect with such a significant and ground-breaking piece of legislation. Development and nature recovery can go hand in hand. We need decent homes and that means more than just bricks and mortar. That means living and working in healthy, resilient places, that means nature. BNG is starting to demonstrate it is an effective approach and a wider world is watching the continued rollout and implementation with growing interest.”