Methodology and Limitations

This page explains the methodology, assumptions and limitations behind EAD Ecology’s BNG Market Analysis.

The dashboard provides indicative market intelligence using publicly available data from the
Biodiversity Gain Site Register.

It is designed to help users understand broad patterns in registered biodiversity gain site supply, observed allocation activity, habitat utilisation, regional activity and recent changes in the public register.

The dashboard is not a valuation tool, legal register, availability checker, demand forecast or ecological suitability assessment. It should be used as a market intelligence resource and as a starting point for further investigation.

1. Data source

The dashboard is based on publicly available information from the
Biodiversity Gain Site Register.

The public register includes information on registered biodiversity gain sites and, where available, associated allocation records.

This may include site reference numbers, local planning authority information, planning references, habitat descriptions, allocated area or length, and biodiversity unit values.

EAD Ecology processes this public data to generate dashboard outputs. The processing does not create new ecological survey data, does not verify legal agreements and does not confirm commercial availability of units.

2. Tracking period

EAD Ecology’s dashboard tracking began on 26 May 2026.

Time-based metrics in the dashboard should therefore be interpreted as activity first seen within EAD Ecology’s tracked dataset, not necessarily the legal date on which an allocation was made.

For example, Allocations Last 7 Days means allocation events first seen in the tracked register data during the last 7 days.

It does not necessarily mean that the legal allocation was created during that exact period.

Because tracking began on 26 May 2026, early time-period comparisons may appear volatile.

A single week with several large newly detected allocation events can represent a large share of the tracked total.

3. Allocation event methodology

Allocation records in the public register may appear as multiple rows. A single allocation event can include habitat, hedgerow and watercourse components, and may include multiple habitat descriptions.

To avoid counting every component row as a separate allocation, the dashboard groups allocation records into allocation events using:

  • Site code.
  • Local planning authority.
  • Planning reference.
  • Project name.

This grouping is used to produce recent allocation metrics and the Top 10 Allocations table.

4. First-seen date methodology

Where an allocation event contains multiple component rows, the dashboard uses the earliest first_seen_date across those rows as the allocation event’s first-seen date.

This prevents later component updates to an existing allocation from being counted as a completely new allocation event.

For example, if an allocation event has component rows first seen on 20 June, 21 June and 22 June, the allocation event is treated as first seen on 20 June.

Later component rows may update the allocation’s total area, length, units, habitats or latest tracked update date, but they do not reset the original allocation event first-seen date.

This distinction is important:

  • First seen date means the earliest date the allocation event appeared in the tracked data.
  • Latest seen date means the latest date on which a component row for that allocation event was first detected.

5. Recent allocation metrics

Recent allocation metrics are based on allocation events first seen in the tracked dataset during defined time periods.

These include:

  • Allocations Last 7 Days.
  • Allocations Last 30 Days.
  • Allocated Units Last 7 Days.
  • Allocated Units Last 30 Days.
  • LNRS recent activity.
  • South West recent activity.
  • Top 10 Allocations Over Last 30 Days.

These metrics are useful for understanding recent register activity. However, they should not be interpreted as legal allocation dates unless confirmed directly from the register, planning documentation or legal agreements.

6. Allocated biodiversity units

Allocated biodiversity units are calculated from allocation records in the public register.

The dashboard reports allocated units for:

  • Habitat allocations.
  • Hedgerow allocations.
  • Watercourse allocations.

Unit values are deduplicated at allocation level to reduce double counting where the same biodiversity unit value appears across multiple component rows.

The public register does not always provide enough information to perfectly apportion biodiversity units between individual habitat components where a single allocation covers multiple habitats. For this reason, group-level unit figures should be treated as indicative.

7. Habitat Market Utilisation

Habitat Market Utilisation compares observed allocated area or length against registered area or length within broad habitat groups.

For habitat records, utilisation is based on hectares. For hedgerow and watercourse records, utilisation is based on kilometres.

The utilisation percentage should be interpreted as an area or length utilisation indicator. It is not a remaining biodiversity unit calculation.

For example, if a habitat group has a high utilisation percentage, this means a relatively high proportion of registered area or length in that group has been allocated in the public register data. It does not necessarily mean that biodiversity units in that group are unavailable.

8. Habitat grouping methodology

Habitat groups are broad categories derived from habitat descriptions and habitat type fields in the public register data.

These broad groups are intended to make the dashboard easier to interpret at market level. They do not replace detailed habitat classification or site-specific ecological assessment.

Broad habitat groups may include:

  • Grassland.
  • Woodland and Forest.
  • Heathland and Shrub.
  • Individual Trees.
  • Urban.
  • Lakes and Ponds.
  • Watercourses.
  • Hedgerows.
  • Wetland.
  • Cropland.
  • Sparsely Vegetated Land.
  • Other Habitat.

Where a record cannot be confidently assigned to a main broad habitat category from the available description, it may be included in Other Habitat.

9. Indicative allocated BNG market value

The Indicative Allocated BNG Market Value section estimates the indicative market value of allocated biodiversity units only.

It does not estimate:

  • The value of all registered supply.
  • The value of remaining biodiversity units.
  • The value of unallocated land.
  • The commercial value of any specific habitat bank.
  • The price at which any specific unit has been sold or may be sold.

Indicative values are based on allocated unit totals and external unit price assumptions.

Actual unit values will vary depending on habitat type, location, strategic significance, trading context, legal agreement, delivery risk, management obligations and market conditions.

The indicative market value section is therefore a high-level market intelligence indicator, not a formal valuation.

10. Remaining area and length

The dashboard may show remaining area or length by comparing registered area or length with allocated area or length.

This is not the same as remaining biodiversity units.

Remaining area or length may indicate that registered habitat, hedgerow or watercourse extent has not yet been observed as allocated in the public register data. However, it does not confirm that units remain commercially available.

The public register does not provide enough information to calculate remaining biodiversity units confidently across all sites.

11. LNRS summaries

LNRS summaries aggregate registered supply and observed allocation activity by available Local Nature Recovery Strategy area information.

These summaries are intended to show relative market activity patterns and broad geographic indicators.

LNRS metrics should not be interpreted as definitive assessments of:

  • Local ecological opportunity.
  • Planning demand.
  • Habitat bank suitability.
  • Commercial unit availability.
  • Strategic land value.

LNRS-level outputs should be treated as high-level indicators and should be checked against local policy, ecological priorities, site-specific constraints and current market evidence.

12. South West Market Snapshot

The South West Market Snapshot focuses on register activity associated with areas such as Devon, Cornwall and the Isles of Scilly, Somerset and Dorset.

The snapshot is designed to provide a regional view of public register activity in the South West.

It should be read alongside the same limitations that apply to the national dashboard.

13. Map data

The dashboard map shows registered biodiversity gain sites using available location information from the public register data.

Map outputs are intended to help users understand the distribution of registered sites and observed allocation activity.

Map markers and site-level summaries should not be used as a substitute for site-specific due diligence, land ownership checks, ecological assessment, planning review or legal review.

14. Public register limitations

The dashboard depends on the structure, completeness and consistency of the public Biodiversity Gain Site Register.

Known limitations include:

  • Some records may be incomplete.
  • Some records may contain inconsistent naming or formatting.
  • Some records may change over time.
  • Some allocation events may include multiple component rows.
  • Some unit values may relate to multiple habitat components.
  • The register does not always provide sufficient information to calculate remaining biodiversity units.
  • The register does not confirm private market transactions that are not recorded publicly.
  • The register does not confirm current commercial availability of units.

15. What the dashboard does not do

The dashboard does not:

  • Provide formal valuation advice.
  • Confirm whether biodiversity units are currently available for purchase.
  • Confirm the legal allocation date of a biodiversity unit.
  • Replace the Biodiversity Gain Site Register.
  • Replace a BNG metric calculation.
  • Replace ecological survey or habitat condition assessment.
  • Replace planning advice.
  • Replace legal advice.
  • Assess whether a specific site is suitable for habitat banking.
  • Confirm land ownership or land control.
  • Estimate remaining biodiversity units across all registered sites.
  • Forecast future demand for biodiversity units.

16. How to interpret high recent activity

High recent activity can occur where a large number of allocation events are first detected by the tracker within a short period.

This may reflect genuine recent register activity, delayed publication of records, changes in register structure, or a cluster of allocation events becoming visible in the tracked data.

Because dashboard tracking began on 26 May 2026, early weekly and monthly comparisons may be particularly sensitive to large newly detected allocation events.

Recent activity metrics should therefore be interpreted as tracked register activity, not necessarily the exact date of legal allocation.

17. Recommended use

The dashboard is best used as a market intelligence tool.

It can help identify:

  • Where registered BNG supply is concentrated.
  • Where allocation activity is being observed.
  • Which habitat groups appear more utilised by area or length.
  • Which LNRS areas show higher recent activity.
  • Where further market or site-specific investigation may be useful.

The dashboard should be used as a starting point for further investigation, not as the sole basis for commercial, ecological, planning or legal decisions.

18. Professional support

EAD Ecology can support landowners, developers, planning teams and project teams with:

  • Habitat bank feasibility.
  • Land opportunity reviews.
  • BNG strategy.
  • Development project support.
  • BNG market interpretation.
  • Register data interpretation.
  • Habitat and offsetting advice.

For project-specific advice, contact EAD Ecology to discuss how this data could support your project.

This methodology and limitations page should be read alongside the BNG Market Analysis dashboard. The dashboard is based on public register data and provides indicative market intelligence only.