From environmental evidence to habitat value

An evidence-led picture of the landscape

Nature Equity combines national habitat mapping, agricultural observations, woodland inventories, physical landscape features, soils, peat and coastal evidence to build a detailed picture of each county. Our inference engine reconciles these overlapping sources using explicit rules, retaining the evidence and reasoning behind each classification. County boundaries provide the assessment framework, while checks on geometry and area help prevent gaps, overlaps and double counting.

The model incorporates all 132 unique area-habitat types in the supplied statutory biodiversity metric catalogue for unit parameterisation. This means it can retrieve their statutory parameters; it does not mean every habitat can be identified automatically from national mapping. The habitat types reported in a county reflect the evidence available there. Separate linear habitats, e.g. hedgerows, require their own assessment.

Our Silver Label philosophy

Silver Label describes an evidence-led, modelled baseline whose assumptions remain visible. We preserve detailed habitat information, distinguish direct evidence from inference and retain unresolved cases where the available information cannot justify a precise classification.

Where a provisional best fit is explicitly adopted, we record that assumption and preserve the underlying source evidence. Where uncertainty materially affects the result, we use a range or flag the need for further investigation. Silver Label therefore provides a consistent starting point for planning and survey.

Understanding biodiversity units

Biodiversity units express habitat value in the statutory BNG framework. For area habitats, the baseline calculation considers habitat area, distinctiveness, condition and strategic significance. Creation and enhancement calculations introduce further factors, including delivery time and difficulty.

Our current county baseline outputs combine mapped area and statutory distinctiveness with permitted condition-score ranges where condition has not been surveyed. They are modelled unit ranges, rather than completed statutory assessments, and do not currently apply strategic significance. Existing baseline units also differ from the additional units that a restoration scheme might generate for sale.

Recognising irreplaceable habitats

Some habitats cannot be adequately replaced within realistic timescales. Ancient woodland, blanket bog and other qualifying irreplaceable habitats therefore require separate treatment.

We identify and report these assets separately where the evidence supports doing so. We do not treat them as ordinary saleable “irreplaceable units” or assign them an ordinary statutory credit value. Loss or deterioration requires consideration outside the normal unit calculation and may require bespoke compensation. Excluding them from ordinary monetary totals recognises the limits of financial substitution; it does not imply that they have no value.

A consistent approach to valuation

Where a defensible habitat match exists, Nature Equity uses published private-market benchmarks to illustrate potential economic value.

We provide two price benchmark figures. The first is a Market Value Benchmark useful for developers and BNG sellers. The second is the Statutory Ceiling Value, which is useful to policy makers and residents who want to have a consistent nation wide benchmark to indicate habitat value.

1. Indicative Complete Advisory Market Value

This estimates the financial value of the modelled biodiversity units using market price benchmarks. Where direct market evidence is unavailable, documented estimates extend the valuation across the eligible habitat baseline.

The calculation combines:

• Minimum value: the lower estimate of biodiversity units multiplied by the applicable lower market price.
• Maximum value: the upper estimate of biodiversity units multiplied by the applicable upper market price.

The range can therefore reflect uncertainty in habitat condition, habitat subtype and associated distinctiveness, alongside differences in applicable market prices. Habitat condition affects the estimated number of units; habitat classification can affect both units and the price applied.

“Complete” describes the inclusion of eligible habitats through direct benchmarks and documented estimates. It does not mean every habitat has an observed transaction price.

2. Statutory Ceiling Value

This values eligible modelled biodiversity units using the Government statutory biodiversity-credit price benchmarks recorded in our pricing registry, expressed on an equivalent per-unit basis.

It also shows a range because a fixed price does not remove uncertainty in the number of units being valued. Where the evidence supports more than one habitat classification, different statutory price categories may also apply.

The minimum combines the lower unit estimate with its applicable statutory benchmark; the maximum combines the upper unit estimate with its applicable benchmark.

“Ceiling” describes the model’s statutory-price comparison scenario. It is not a legal cap on private market prices, a market quotation or an amount payable to landowners.

What the figures mean

These are modelled valuation scenarios, not statistical confidence intervals or guaranteed minimum and maximum sale prices. Field surveys and more specific pricing evidence can narrow or change them.

The figures value the existing modelled habitat baseline. They do not establish how many additional biodiversity units could be created and sold, or the income a landowner could earn. Irreplaceable habitats are excluded from ordinary unit-based financial totals.

The market and statutory valuations are alternative perspectives and must not be added together.

Making natural value visible

Our purpose is to expose an important dimension of the natural landscape’s value and bring it into everyday decisions about land.

Habitat biodiversity is one component of natural capital. A broader Natural Capital Assessment (NCA) would also consider benefits such as carbon storage, flood regulation, water quality, recreation and health. The County Championship provides a granular, spatially explicit habitat view that can support that wider assessment while already offering a useful tool for planning, investment screening and survey prioritisation.

Typical sources

The evidence base draws on dozens of national datasets and layers. Typical sources include:

• Habitat and woodland: Natural England’s Living England habitat mapping, Priority Habitat Inventory, Ancient Woodland Inventory, wood-pasture and parkland mapping, and the National Forest Inventory.
• Agriculture: successive annual Crop Map of England datasets, used to assess observed land-use patterns and changes.
• Physical landscape and water: Ordnance Survey mapping of buildings, roads, rail, urban areas, greenspace, woodland and surface water, together with OS Open Rivers.
• Soils and peat: national soil mapping, soil-carbon and soil-series references, and England Peat Map evidence.
• Protected sites: Sites of Special Scientific Interest, Special Areas of Conservation, Special Protection Areas, Ramsar sites and Local Nature Reserves.
• Coastal habitats: broadscale marine habitat mapping, coastal lagoon and coastal priority-habitat evidence, saltmarsh extent and zonation, and Environment Agency coastal asset information.
• Assessment and economics: the statutory biodiversity metric and user guidance, published statutory credit prices, and published private-market biodiversity-unit price reports.

The sources used vary with location, habitat and availability. A dataset’s presence provides evidence for assessment; it does not establish that every mapped feature is present, current or ecologically confirmed.

The wording on units and statutory pricing follows DEFRA’s metric guidance and published credit-price guidance.