Some First Thoughts on GIS, Evidence, and BNG for NSIPs
As I mentioned yesterday yesterday, I am genuinely pleased to see GIS discussed directly in Defra’s Summary of Responses on Biodiversity Net Gain for NSIPs. Until now, the only real reference to GIS in BNG guidance has effectively been “please provide a habitat map”. Anyone working in this space knows how thin that expectation has been compared to what is actually required to make BNG function. So a big thank you to those who contributed to the consultation with this message. I’ve summarised some of my main points below and will go into more detail on each over the next few weeks, as there is quite a lot to digest, even just from a GIS standpoint.
It does feel like a small victory to see GIS and spatial evidence acknowledged. I’ve said many times that BNG is a spatial process. The metric is important, but it sits on top of a chain of spatial decisions that begin long before anyone opens Excel. That said, acknowledgement on its own is not enough. Without follow‑through, the same problems will resurface.
Having multiple structures stages for the overall BNG process feels positive, as this is where requirements can be implemented and expectations set. Data requirements appear to be a gap in the summary diagram, but in my opinion they should apply across scheme conception and pre‑application. I would like to see GIS required as the evidence base for site selection. There is certainly no shortage of environmental data available to support this.
Treating GIS as primary evidence rather than supporting material is a necessary shift if BNG is to be reviewable and monitorable over time. However, this hasn’t been discussed in any further detail. An implementation plan will be needed, including a more detailed look at the full BNG workflow and questions around data ownership, responsibility, and liability.
Moving away from Excel‑first workflows makes the process far more compatible with GIS, which underpins the entire BNG calculation. A digital platform is an ambitious step. While it could help resolve some data standard issues, such as format, development would need to begin soon to align with the November 2026 mandatory compliance date.
I agree with the consultation that BNG needs independent verification and validation if we are to build real trust in the outcomes. This is where FRIDAS stems from; with consistent data requirements comes clarity, auditability, and the ability to review evidence properly. There should also be space for validation from an ecological standpoint, regarding ecologist expertise and the use of habitat classification streamlining tools.
I think the delay until November 2026 is sensible, provided Defra uses this time to continue developing the policy and supporting guidance.
I also found it interesting that 44 percent of respondents felt the current proposed evidence requirements were sufficient. That suggests a significant part of the sector is either comfortable with the status quo, or interpreting the word “sufficient” differently depending on experience and role.
All in all it feels like this is going in the right direction, but it’s currently all words. I’ll be keen to see how Defra navigate the next few months. Stay tuned for more.
Relevant FRIDAS Fieldnotes articles:
BNG Needs to be Treated as a Design Requirement: https://www.linkedin.com/pulse/bng-needs-treated-design-requirement-ecospatial-solutions-lfrfe/
GIS Needs to Lead BNG: https://www.linkedin.com/pulse/more-than-map-gis-needs-lead-bng-ecospatial-solutions-k8ise/
Building Trust in BNG with a Seal of Approval: https://www.linkedin.com/pulse/building-trust-bng-data-seal-approval-ecospatial-solutions-5s0ge/?trackingId=%2FFC7yRZtSlmfYFdnGj5hIg%3D%3D
