Mandatory biodiversity net gain applies to NSIP applications made on or after 2 November 2026. At the time of writing there are roughly ten weeks left.
This piece is about scope rather than reassurance. If you are looking at a development consent order application and trying to work out what baseline position you can reach before the date, or what to do if you cannot reach one, this is the honest version.
We would rather tell you what is not achievable than sell you something that falls apart at examination.
First, work out whether you are actually caught
Before scoping anything, confirm the requirement applies.
The regime catches applications for development consent made on or after 2 November 2026. It does not catch changes to an existing development consent order where the original application was not subject to mandatory BNG. Some material change applications will therefore sit outside it.
There are no sector exemptions. Every NSIP type is in scope, and the territorial extent runs onshore to the mean low water mark. Marine net gain is a separate question still under government consideration.
If you are caught, the next question is what your baseline has to cover, and that is narrower than many teams assume. BNG applies to habitats negatively impacted by the development, temporarily or permanently, plus any habitat where you will create or enhance to deliver gains. Unimpacted habitat inside the order limits can be excluded where an ecologist confirms no loss and no deterioration in condition. The full picture is in BNG for NSIPs: what changes on 2 November 2026.
What can be done in ten weeks
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A full habitat extent and classification across the order limits. Yes.
Remote habitat mapping from satellite and aerial imagery can classify habitat across a large corridor in weeks rather than seasons, at any time of year. As a reference point, we have delivered 4,500 hectares in six weeks. Classification aligns to the habitat categories used by the statutory biodiversity metric, covering more than 35 habitat types plus linear features such as hedgerows.
This gives you the map. It does not give you the submission.
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A defensible BNG boundary position. Largely, yes.
The boundary plan has to distinguish four categories: negatively impacted habitat, habitat contributing to gains, unimpacted habitat included in the baseline, and unimpacted habitat excluded from it. Building that drawing requires knowing what habitat sits where across the whole order limits, which is exactly what remote mapping produces. The exclusion argument still needs an ecologist's confirmation and reasoning, but they can make that judgement from a mapped position far faster than from a blank corridor.
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A first-pass metric calculation and units estimate. Yes, with caveats.
Enough to understand the scale of the obligation, test design options, and have an informed conversation about on-site versus off-site delivery. Not enough to submit.
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Identification of high-risk features. Yes, and this is where the value is.
Probable irreplaceable habitat, priority habitat, high-distinctiveness parcels and connectivity constraints. Irreplaceable habitat in particular sits outside the baseline and outside the 10%, requires bespoke compensation, and cannot be addressed with statutory credits. Finding it late is one of the more expensive discoveries available on an NSIP.
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Off-site requirement scoping. Partly.
You can size the likely shortfall. You cannot complete gain site registration in the time available, and the guidance is explicit that lead times for off-site registration need to be built into programmes.
What cannot be done in ten weeks
Being direct about this matters more than the list above.
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Condition assessment to submission standard, if you are outside the season.
Habitat condition for the statutory metric is judged on the ground, in the growing season, by a competent person. In September and October you are at the tail of that window for most habitats and past it for some. Sub-optimal survey data is not automatically invalid, but it is weaker, and it is exactly the sort of weakness that gets tested. We go into the seasonality problem in the NSIP survey season problem. -
A full protected species picture.
Breeding bird, great crested newt and reptile windows have closed for the year. Bat hibernation surveys do not open until November. No amount of resourcing changes this. -
A draft habitat management and monitoring plan built on new ecology. A draft HMMP is required at application, and it depends on habitat design and management planning that follow from a settled baseline. If the baseline is being built now, the HMMP is not going to be ready in the same ten weeks.
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Gain site registration.
Registration is a paper process with its own timeline. -
A submission-ready outline biodiversity gain plan from a standing start.
If you are starting the ecology now for a pre-November application, the realistic outcome is a strong evidence base for a post-November application rather than a rushed pre-November one.
If the window has closed
For most teams starting now, it has. That is not a disaster, and the alternative is worse.
An application submitted before 2 November purely to escape the requirement, but not genuinely examination-ready, invites challenge during examination. Time lost in examination is more expensive than time spent on a baseline, and it is less predictable.
The more durable position is to accept the requirement and get ahead of it:
- Map the full order limits now. Habitat extent and classification do not depend on the season, and the map is the foundation for everything else. Doing this over the winter means field teams start in April knowing where to go.
- Fix the boundary argument early. Decide, with your ecologist, what is impacted and what is excluded, and record the reasoning while the design rationale is fresh.
- Screen for irreplaceable and high-distinctiveness habitat immediately. This is the finding most likely to change the design, and design changes are cheapest now.
- Book the 2027 survey season in 2026. Competent ecologists are a constrained resource and the November date has concentrated demand. Field capacity for next spring is being committed now.
- Check the age of any existing survey data. Data over three years old is unlikely to be valid, and data between eighteen months and three years needs an ecologist's review. Better to find that out in October than in March.
What we can tell you, and what we cannot
Gentian produces habitat baselines remotely, at NSIP scale, in any season. Our parcel-level habitat accuracy has been independently validated against chartered ecologists, and on a 1,700-hectare assessment we took a programme from eighteen months to five.
We are equally clear about the boundary of that. Remote assessment is not a substitute for the ecologist, for field verification, or for the statutory submission they put their name to. Our screening products support scoping, feasibility and risk work rather than fulfilling the compliance obligation directly. What we add is a wide, consistent, early view that makes the field effort land in the right places, and a confidence layer that tells you where remote assessment is reliable and where it is not.
If you want a scoped answer for a specific order limit, book a call. Bring the red line and the target application date and we will tell you what is reachable.