Biodiversity Net Gain 

Biodiversity Net Gain is a flagship policy of the forthcoming Environment Bill. The policy requires all eligible (ie most) developments to deliver a 'net gain' in biodiversity, using habitat as a proxy measure, of 10% above pre-existing levels. Below you can find a rough guide to the process.

Firstly, an ecological site survey is carried out to ascertain, using the 'Defra metric 2.0', the number of 'units' of habitat that exist onsite prior to works commencing.

10% is added to this number. This 110% constitutes the minimum units of habitat the development much provide for by the end of the scheme. 


Developers are obliged, through something called the mitigation hierarchy, to deliver as much wildlife habitat on site as they can, in the form of high quality green infrastructure. 

In some instances, not all habitat gain will be able to be delivered on site, and developer will then be required to demonstrate that they have delivered that habitat offsite. This will usually be done through the purchase of biodiversity credits, which are expected to cost somewhere in the region of £10,000 - £15,000 per unit depending on habitat type, location etc. Currently three options exist for delivering offsite gains - purchase credits through a government led scheme (which they hope will be a 'last resort); purchase credits from the national Environment Bank; or through agreements made directly between landowners and developers. None of these are designed to ensure maximum environmental benefit locally.

A fourth option is possible. Biodiversity Net Gain will be delivered through the planning system, and in that sense Local Planning Authorities (in Gloucestershire, these are the District Councils) are responsible for ensuring the roll-out of the policy. The Gloucestershire LPAs are working with the Local Nature Partnership to develop a coordinated, consistent, locally delivered approach, creating a level playing field from district to district and ensuring that money stays in the county to deliver habitat in the county against local priorities and evidence.


For this, a Natural Capital Investment Trust is required. The Local Nature Partnership has been approached frequently by developers wishing to explore routes to demonstrate compliance with this forthcoming policy (awareness that this will be looked upon favourably by the LPAs appears high) so we are working hard to bring this forward well in advance of the policy becoming law.

The policy has the potential to create a new large funding stream for delivering nature's recovery at scale through offsite, landscape-scale projects, whilst ensuring a higher likelihood of green infrastructure being designed into housing developments - a real plus for ecological connectivity, peoples health and wellbeing, air quality, carbon sequestration, natural flood management and more. 


Evidence from the Nature Recovery Network mapping shows where there are opportunities to deliver the maximum benefits for ecosystem resilience and connectedness. The Natural Capital mapping highlights where opportunities exist to design projects that can deliver multiple benefits. Both can be used to guide both onsite and offsite habitat creation. All this will be done in close alignment with the emergent Local Nature Recovery Strategy.

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