BNG Location Checker

Use this tool to check the spatial multiplier for using Sutton Mead BNG units at your development location.

Enter a location to see its LPA, NCA and relationship to Sutton Mead.

If you don’t know the postcode or grid reference, click the map to place a pin.

Sutton Mead

LPA = Local Planning Authority — the authority responsible for local planning decisions.
NCA = National Character Area — a landscape area defined by its shared natural and cultural features.

Rules, sources and limits

How the result is worked out

The checker compares your location with Sutton Mead using two types of area: the Local Planning Authority (LPA), which deals with planning applications, and the National Character Area (NCA), which groups landscapes with similar features.

Same area — 1:1. If your development shares either area with Sutton Mead, each Sutton Mead unit counts as one unit towards your requirement.
Adjacent area — 4:3. If neither area is the same, but either is next to Sutton Mead’s area, four Sutton Mead units count as three.
Distant area — 2:1. If neither area is the same or next to Sutton Mead’s area, two Sutton Mead units count as one.

Ratios are shown as Sutton Mead units : units credited to your development. This checks geography only. It does not confirm whether suitable units are available, their price, or whether they meet all your project’s requirements. It covers terrestrial area habitat and hedgerow units, excluding watercourse and intertidal units.

When a closer check is needed

A postcode, grid reference or pin identifies one point, not your whole development site. If your site crosses an area boundary, its full planning application boundary needs to be checked. The metric can recognise any LPA or NCA the impact site spans.

If a point is close to a boundary or the boundary data is unclear, the checker shows Review instead of a single multiplier. A postcode point may be some distance from the actual site. For map pins, the nearest postcode is shown for reference only; the calculation uses the pin’s position.

Maps and locations

The map combines the LPA and NCA rules: green means the same LPA or NCA; gold means a neighbouring LPA or NCA where neither is the same; grey means neither the same nor neighbouring. Both Sutton Mead reference boundaries and the combined shading appear after a location is checked. The map outlines are simplified to load quickly. Calculations use the full official boundaries. Locations are shown as a British grid reference, with eastings and northings below it. A grid reference is a way to find a place on an Ordnance Survey map; it does not make an approximate location more precise.

Sources and dates

The rules come from Defra’s statutory biodiversity metric guide, November 2026, pages 39–40. The calculation tool was version 1.1.1 when checked on 11 November 2026.

Technical details

Calculations use British National Grid coordinates (EPSG:27700). Neighbouring areas must share more than one metre of boundary. Point-only contacts, gaps or overlaps within 10 metres are flagged for review. This is the checker’s approach to interpreting the map data; the statutory guide does not set these tolerances.

The checker looks for boundaries within 1 km of postcode points, 15 metres of map pins, and the grid-reference cell size plus a five-metre allowance. These are review margins, not guarantees of location accuracy. Map-pin coordinate conversion is approximate. The displayed grid reference identifies a 100-metre square.

Your searches

The checker does not save your searches. Postcode lookups and map-pin coordinates are sent to postcodes.io and map tiles are supplied by OpenStreetMap. Those providers receive the requests needed to supply their services.

© Natural England copyright. Contains Ordnance Survey data © Crown copyright and database right 2023. LPA boundaries contain OS and ONS intellectual property. Reused under the Open Government Licence v3.0.