Image: drone flying over grasslands.
Biodiversity Net Gain (BNG) was made official in 2024, so if you are a developer or a planner, you need to think about how to apply this to your projects.
Biodiversity Surveyors is building a vast network of nature recovery sites across every local planning authority in England. These habitat banks are generating the high-quality biodiversity units that developers need to satisfy their BNG obligations and that long-term planning requires.
Developers and planners might ask themselves whether it’s more effective to deliver outcomes for nature, local communities, and development projects themselves on-site or off-site. It is vital for developers and planners to understand the many available options.
Delivering Biodiversity Net Gain
When it comes to delivering mitigation measures, there are two options.
The first is to directly counteract impacts to habitats inside the development site. To do this, you need a lot of investment in resources and it can be hard to achieve the desired results.
Secondly, there is an option to create habitats outside of the development site. This is similar to the construction of a water treatment facility: a part of the development project might need a water treatment facility to function, and so the developer pays for the facility. But the water treatment facility is not a part of the development itself.
The Department for Environment, Food, and Rural Affairs (Defra) specifies in its mitigation hierarchy that, first and foremost, any development should seek to avoid initial biodiversity loss. Unfortunately, development often leads to some form of biodiversity loss, so biodiversity offsetting seeks to counteract that. A developer can achieve offsetting through several means, including avoidance, conservation, or creation of habitats. To comply with UK law, any loss must be matched with at least a 10% net gain.
When a developer can’t achieve the compulsory 10% total biodiversity net gain on the actual development site, there exists a variety of off-site opportunities that may well yield even greater biodiversity boosts and community benefits over the long haul.
This can involve delivering biodiversity net gain locally, even if that means working off-site. This is a good thing because delivering these benefits onsite or in nearby locations is more valuable, so there’s no upscaling in the spatial risk multiplier that increases the cost of delivering benefits at a distance. Therefore, we’re not penalised for the nearby delivery method.
Off-site Biodiversity
There are three basic types of off-site delivery:
- The BNG in NCA (National Character Area) or LPA
- BNG is located within a neighbouring local planning authority or national character area
- BNG extends far beyond the neighbouring Local Planning Authority or National Character Area
BNG that is delivered in the local planning area or national character area is the kind that the biodiversity metric spatial risk multiplier affects the least. That is why planners and developers must make this option their first port of call. It maximises several important outcomes for both parties as it keeps development-related BNG costs low for the developer whilst boosting local impact.
Image: three surveyors standing on grassland conducting a biodiversity surveyor.
BNG Benefits
Delivering nature recovery at such scale within an LPA/NCA has many benefits—let’s take a look at some of them.
The first is economic: large nature recovery projects create jobs, as the recent project in the Tees Valley shows.
The second is social, as off-site delivery extends community access to nature, contributing to wellbeing.
The third is environmental. Off-site delivery allows for habitat creation at a scale that contributes to the local authority’s broader environmental goals.
If a local planning authority has declared a climate emergency or has a local nature recovery strategy that is active, then an understandable biodiversity net gain delivery plan can be adapted to support this.
Advantages of Off-site Biodiversity Units
It should be known that BNG was created for the benefit of nature: restoring ecological networks, establishing vital wildlife corridors, and augmenting the services that ecosystems provide. This includes cleaner water, increased carbon sequestration, improved species abundance, and enhanced soil health for natural flood management.
In contrast to on-site restoration, off-site biodiversity measures do not create isolated islands of biological diversity. Off-site measures allow landscape-scale restoration, connecting areas of ecological importance. We can now link ancient woodlands, for example, to Sites of Special Scientific Interest (SSSIs) in landscape-scale restoration projects. Off-site actions allow us to reconnect landscape features, core habitats, and ecological corridors using principles of effective ecological network design.
Off-site Habitat banks are created on land leased from local landowners. Their design involves close collaboration with the local authority. They are monitored by experienced ecologists and managed in partnership with the ecological land use community, using a habitat management plan that is sufficiently detailed and clear to guarantee delivery of biodiversity net gain (BNG).
On-site delivery
Planning proposals for on-site delivery need to be constructed in a way that makes project delivery realistic and likely, even when pressure on developable land is intense. These proposals must also guarantee that biodiversity and habitat restoration provide a real and significant uplift in the region for at least 30 years (if not longer).
The frequent shared use of residential areas can hinder the types of long-term maintenance that biodiverse habitats require to meet DEFRA’s exacting standards. This is a serious problem that could lead to habitat failure and further biodiversity loss.
There is an incredibly limited opportunity for biodiversity benefits to come from large warehouses, retail buildings, port facilities, and the infrastructure of the similar sort. Obviously, these big concrete structures with large paved parking areas are not places for investing in nature. So, these developments are not part of providing any uplift in biodiversity on or near their sites, which is why off-site delivery is opted for.
Moreover, conservation covenants and section 106 agreements must regulate any spaces that are part of biodiversity net gain (BNG) delivery. This includes buildings with green roofs for BNG. Once a public space or piece of legally binding infrastructure is committed to BNG, that space is effectively frozen for 30 years, with no alterations allowed. This puts serious limits on space utility, which in turn constrains what can happen in and around that space in the name of “development.”
Besides the costly management and monitoring of habitats, the on-site delivery of biodiversity net gain (BNG) frequently necessitates that green spaces be unfriendly to recreation and the provision of amenities that have people at their center. This is, in part, because BNG does not directly benefit human use; rather, its purpose is to serve wildlife.
Hybrid options
Solutions that blend off-site and on-site provisions can contribute helpful ways to offset habitat loss, particularly where on-site areas of habitat, such as woodlands, have been preserved but other types of on-site habitat, such as grasslands, have been degraded but could potentially be restored somewhere nearby.
Thus, if a developer seeks planning consent, they should always consult with an experienced ecologist, whom we can put you in touch with at Biodiversity Surveyors. That way, you can be sure to understand the planning consent process thoroughly, along with the current laws and regulations that govern it.
Conclusion on Off-site v On-Site BNG Delivery
Developers must make sure that the 10% uplift over and above existing conditions is secured and that any biodiversity loss is fully compensated for either on-site or off-site. This is why it is recommended to buy biodiversity units in situations where it is not achievable to get on-site mitigation for habitat loss.
We have a network of Habitat Banks, some of which have secured hundreds of millions of pounds in sustainable funding and are in the process of creating over thousands of hectares of new habitat across the country. This provides a pretty good backdrop for any developer to work with.
If you are a developer and you have to meet the BNG (Biodiversity Net Gain) requirements, then you could meet those requirements with our assistance.
Regardless of which remedy you select, the centre of a successful local BNG strategy is seeing this as an unprecedented chance for nature recovery and to the benefit of your local community.
