The Spatial Risk Multiplier: What Is It, Why It Matters, and How Developers Can Avoid It
Biodiversity Net Gain (BNG) is now a legal requirement. For every development in England, the site must deliver a minimum 10% net gain in biodiversity. But when onsite delivery isn’t possible, and developers turn to off-site compensation, the Spatial Risk Multiplier (SRM) quietly becomes one of the most important factors in planning.
It can impact how many biodiversity units are needed, how much a project costs, and how quickly it gets approved.
So what is the Spatial Risk Multiplier? And how can developers avoid its penalties?
Let’s break it down.
What is the Spatial Risk Multiplier?
The SRM is a calculation tool built into the Biodiversity Metric, designed to encourage local compensation, ensuring that any biodiversity losses are replaced as close as possible to the development site.
In simple terms, the further away your off-site biodiversity units are from your project, the more units you’ll need to deliver.
How Does the SRM Work?
The multiplier is applied when developers source off-site units from a habitat bank that is not in the same Local Planning Authority (LPA) or National Character Area (NCA) as their project.
Here’s how it scales:
The takeaway? The wrong location can cost you more, if not double the amount of units.
Why it Exists
The multiplier is part of Natural England’s strategy to ensure that biodiversity losses are meaningfully replaced, ideally in the same landscape, ecosystem, and policy context as the loss itself.
This approach supports ecological connectivity and delivers more relevant, measurable outcomes. But for developers, it means off-site BNG can’t be approached casually; location now has direct implications for compliance, cost, and planning success.
How Dragonfly Helps Developers Navigate the SRM
At Dragonfly Habitat Bank, we’ve designed our site portfolio specifically to reduce the impact of the SRM.
Our three banks are strategically positioned across England, covering a wide range of development catchments and NCA overlaps:
✅ Southburn – East Yorkshire & the Humber
✅ Wychnor Meadows – Staffordshire & the West Midlands
✅ Wood End – North Warwickshire & surrounding LPAs
Because our banks are located within priority areas, many of our developers avoid the SRM completely, sourcing their units locally and compliantly.
What Developers Should Do Now
If you’re working on a site and considering off-site units, it pays to:
Review which NCA and LPA your development falls under
Compare it to the location of the biodiversity units being offered
Factor the SRM into both cost and compliance calculations
And most importantly, speak to your habitat bank provider early. Strategic sourcing is easier before planning is locked in.
Need Help With Your BNG Strategy?
We work with developers like you to source the right units in the right places — so they stay compliant, cost-effective, and on track.
If you’re looking for support, we’d love to talk.
Biodiversity net gain, without the pain
We've made it easier than ever to play a crucial role in ensuring sustainable development. At Dragonfly, we offer our partners a turnkey solution for meeting BNG obligations off-site, including developers, planning authorities, and landowners.
We offer professional advice and support to help our partners navigate the complexities of habitat banking and BNG compliance.