Image: Photograph of five panellists at the RESI 2022 conference
Biodiversity Net Gain is a legal requirement for development in England. If it is shown that a site has not achieved it, planning permission risks denial. Developers must therefore address the potential impact of their projects on biodiversity and either demonstrate very clearly that what they are doing is having a neutral or positive impact or face the consequences of not getting their planning applications approved.
Property Week’s RESi conferences often make a real splash with the hot topic of “net zero.” They field the big questions on this important issue and offer some enlightening answers.
What is Biodiversity Net Gain (BNG)?
It is the law that a development project must deliver a minimum of 10% more biodiversity to make up for any loss of biodiversity it creates. Which law? The Environment Act 2021. It requires the statutory biodiversity metric to work out how much biodiversity has been lost as a result of a development project and how much more has to be delivered—by the project, or somewhere nearby, or however far away the developers need to go—to get back to a state of “no net loss” or, preferably, “better than before.”
When Should You Start Planning for BNG?
Now. Every single planning permission, including units of just one dwelling, section 73 applications, and 73A retrospective applications, will have a pre-commencement condition automatically imposed on it. What will that pre-commencement condition say? It will say that a biodiversity gain plan must be submitted and approved by a local planning authority before any development can start.
What is Biodiversity Unit and How do You Calculate them?
The Biodiversity Metric adopted by DEFRA provides a way to assess the biodiversity value of a site. Ecologists trained in the methodology collect ecological data from a site. This data informs an assessment of the site’s baseline biodiversity condition when compared to the metric.
The proxy that the metric uses for biodiversity is a combination of habitat type, condition, and distinctiveness. “Distinctiveness” refers to the relative value of the habitat based on how common or rare it is. The condition assessment is the ecologists’ judgement of how well the habitats hold up to the rigours of the “Natural England” health-check.
Next, take the developed design and insert it into the biodiversity metric. This reveals the overall biodiversity score of the site on balance. Or, put another way—the existing value of the site minus the value lost through development plus the value created in the design equals the biodiversity score of the site (in balanced terms, a good score is achieved when development does not disrupt the existing ecological community, and the design either doesn’t interrupt it or facilitates the continued existence of the ecological community and/or the community’s facilitation of other ecological communities).
It is advised that the variety of habitats found on the site is taken into consideration as early as possible in the lifecycle of site selection and design to minimise the impact of the development while still allowing for the efficiencies of reasonable development. Certain habitats are of higher value and are classified based on how distinctive they are, which is a value classification that considers rarity, distribution, and how much legal protection the habitat has. Losing these higher-value habitats is going to make the 10% net gain somewhat more elusive and thus somewhat more expensive.
Depending on the results of assessing the development project’s biodiversity metric, following the mitigation hierarchy, more biodiversity units may need to be secured off-site to achieve the 10% net gain target. If that’s the case, developers might well approach an organisation like Environment Bank to acquire of-site BNG Units from a Habitat Bank.
Image: surveyor flying drone in brown field.
How Do Environment Bank’s BNG Units Work?
We are sourcing a Habitat Bank in every local authority across England. 30 years of habitat creation are pre-funded so that they can then raise BNG Units, which are aligned to the biodiversity uplift. These BNG Units can be easily bought by developers to satisfy their biodiversity net gain (BNG) requirements.
The onus of looking after the habitats, once they are up and running, will lie with the developer or their management company (i.e. the Habit Bank provider). If the provider does not achieve what we say they will, the local authority can enforce requirements. Good providers enter right at the start into performance bonds and section 106 agreements in relation to the Habitat Bank. They also register with Natural England.
Is BNG More About Quality than Quantity?
Most of the time, habitat quality is much more critical than sheer size.
When we define habitat quality, we should not just define it in terms of biodiversity value, but also in a wider suite of ecological contexts that make suitable habitats realistic and deliverable. Setting targets that are unrealistic will guarantee failure when it comes to ensuring that biodiversity is uplifted.
This is why we consider the habitat’s location to be strategic. You’re fitting nature into the strategic parts of the landscape and so developers need to be context-aware. For example, putting carbon-sequestering trees in climate-change-impacted places where their uplifted biodiversity can provide services necessary to mitigate local flooding and making nature there much more complex and resilient, thus also significantly impacting local ecosystem services. These are benefits for both humans and nature.
Does BNG make building on brownfield sites more alluring?
It depends on the site specifics. Take brownfield land, for example. Some of the rarest and most valuable habitats in the country are found on this type of land and may be next to impossible to recreate. Proposing new development on such a site and claiming that it will net biodiversity gains runs counter to reason and would probably result in pretty poor planning outcomes—making it a case of what not to do.
The same principles apply more generically to development on land that has any type of distinctive habitat on it, which is why it pays to engage with an ecologist early in the master planning process.
What will BNG do for house building?
In two decades, we would like to assert that BNG has proven governance matters more than even the policy specifics and that regime success hinges on good governance.
We want to see it having had a really positive influence and it seems we’ll then look back at BNG such that we are glad we did it, at the very least because it seems not too difficult to imagine BNG halting the decline and achieving ‘biodiversity gain’ in England and perhaps further afield. This should all happen while delivering affordable housing, along with efficient spaces to work and live, in places that are enjoyable to inhabit.
How can you help a Developer who is building a Large Project?
After an initial master planning exercise, a developer will approach Biodiversity Surveyors. They will inform us as to whether or not they have a residual loss of BNG Units. This number is determined by the developer’s own ecology team or perhaps a consultant we have provided them with. If there is a required net gain, we organise selling the developer the necessary BNG Units drawn from one of our established Habitat Banks. These are sites across the country which have already set up certain kinds of ecological restoration and conservation projects.
If there is no Habitat Bank in the vicinity, then we can at lease give you an indication as to when a site will be available, which allows the developer to proceed with his planning application.
To talk about purchasing or reserving BNG Units, please complete our BNG Unit request form.
