A new report suggests developers and Downing Street should change the focus from on-site environmental investment to larger off-site projects to deliver greater impact.
The Comparative Value of On-Site v Off-Site Biodiversity Net Gain of Restoring Nature has been produced by a number of high profile experts in the sector.
And, acccording to their analysis, the UK Government’s BNG scheme — wherein new developments must positively contribute to a site’s ‘biodiversity score’, or buy credits in nature recovery projects elsewhere – needs to shift its focus. Currently, on-site projects are the first port of call, but evidence is mounting that this approach is suboptimal from both economic and ecological perspectives.
Co-authored by Nina Pindham of Cornerstone Barristers, Rural Research Director at Strutt & Parker, Jason Beedell, Neil Beamsley — Group Head of Biodiversity at Bellway Homes Ltd — and Robert Hindle, Executive Director of Rural Solutions, the paper advocates adjusting Downing Street recommendations to reflect data. Specifically, rather than trying to squeeze BNG points out of unsuitable sites, which are often too small to deliver significant results, larger endeavours, located of-site, are the way to go.
‘Most developments are too small to deliver any meaningful on-site biodiversity value through BNG and such areas have a short shelf life because the 30-year management liabilities on developers are usually handed over to ill-equipped management companies,’ says David Hill, Deputy Chair of Natural England and Founder of Environment Bank, who also authored the paper. ‘But, led by the policy, developers have been favouring on-site solutions.
‘Removing this preference, as is proposed in the recent government consultation on BNG and nationally significant infrastructure, will make it easier for developers to deliver their legal compliance by purchasing off-site BNG units,’ he continues. ‘This is far better for biodiversity and cheaper for the developer. Housing residents would still benefit from managed landscaping and planting (through landscaping conditions) but without conflating this with biodiversity uplift.’
Key findings include:
- Ecological performance: On-site BNG is typically delivered in small, fragmented and disturbed areas, offering very limited biodiversity uplift. Off-site BNG, by contrast, is delivered on larger, better-connected sites with professional management and long-term funding, enabling more meaningful and measurable ecological outcomes.
- Cost efficiency: On-site BNG units can cost considerably more when land value and lost development potential are fully accounted for. Off-site units cost approximately £27,000 each. Modelling shows that the costs of delivering just 10% of the total BNG requirement on-site are substantial at about 4x the cost of delivering all of the BNG requirement off-site.
- Developer impact: On-site BNG could add a cost of £12,000-£15,000 per house (which is approximately 4% of the sale price of a typical new build house, or £400-£500/year for a 30 year term), compared with £3,000 (about 1% of a typical new build house sale price, or £100/year) when all the BNG requirement is delivered off-site. Developers are often pressured to deliver BNG on-site because of the policy preference implemented by planning authorities, even when it reduces housing numbers and increases risk.
- Governance and enforcement: On-site BNG is rarely monitored or enforced, with long-term liabilities often passed to residents’ associations or management companies. Off-site BNG is secured through legal agreements and subject to formal oversight, offering greater certainty for Local Planning Authorities (LPAs) and developers.
- Market potential: Despite government expectations that over 50% of BNG would be delivered off-site,10% or less of the BNG requirement is currently being delivered off-site. Increasing this will drive a private market for nature, enhance the UK’s leadership in nature finance and boost delivery against the target to restore 500,000 hectares of nature by 2030
‘The world is watching England’s BNG regime with keen interest, but, as with all new regimes, lessons are being learned. Implementation has already led to a consultation on making the regime work better for those who find it prohibitive to provide small parcels of on-site BNG,’ adds Cornerstone Barristers’ Nina Pindham. ‘The conclusions of this report show that the obvious means of solving that problem (buying off-site BNG units) saves money, and leads to better, bigger, more certain gains for nature overall.’
A number of recommendations have now been made, which the UK Government should take into consideration in its ongoing assessment of current regulations:
- Reconsider the on-site preference and support off-site delivery: Government should remove the sequential preference by the LPAs for on-site BNG and enable developers to purchase off-site units from professionally managed habitat banks. This would unlock larger-scale nature restoration, reduce costs and complexity for developers, and accelerate housebuilding. Biodiversity restoration and greenspace provision should be treated as distinct objectives.
- LPAs should champion off-site BNG delivery: Local planning authorities should promote off-site BNG through local plans and development management and local nature recovery strategies, offering a faster, simpler, and more effective route for developers and LPAs alike.
- Strengthen compliance and enforcement for on-site BNG: LPAs should be given the necessary tools for monitoring and enforcing on-site BNG, in particular appropriate resources to ensure delivery and rectify failures and hence should be held more accountable for monitoring and enforcing on-site BNG.
- Create a level playing field between on-site and off-site BNG: If on-site BNG is retained, it must meet the same standards as off-site delivery: transparent registration, secured 30-year funding, and professional management. Both approaches should adhere to the Defra/BSI nature standard.
- Improve government communications on BNG: Central government should review and enhance consistent public messaging around BNG, clearly articulating its benefits for both biodiversity and society.
Image: Aiokr Chen / Unsplash
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