Free tool
Grey Belt checker
Test a location against the published indicators behind the NPPF Grey Belt definition — Green Belt status, previously developed land, containment and constraint overlaps.
Check Grey Belt indicators
Enter a postcode, address or place name in England. The check queries the national planning datasets published on planning.data.gov.uk and reports what is recorded at that point. It is decision support, not a planning decision.
The Grey Belt test
The NPPF (August 2026) defines grey belt in its Annex B glossary as land in the Green Belt comprising previously developed land or any other land that does not strongly contribute to the policy GB2 purposes (a) checking unrestricted sprawl, (b) preventing neighbouring towns merging, or (d) preserving the setting and special character of historic towns — and which is not land where policies for designated areas or assets would provide a strong reason for refusing development.
There is no national Grey Belt map. Land has to be assessed against the definition, which means a purposes assessment for the specific parcel supported by evidence.
What the indicative check reports
The check confirms whether the location is recorded in the Green Belt and then reports the indicators available from published data: previously developed land status from the brownfield register, containment relative to the built-up area boundary, and whether absolute or heritage designations overlap the point.
It produces an indicative rating only. Purposes (a), (b) and (d) are matters of planning judgement about a parcel's role in the wider Green Belt, and no dataset settles them.
The Golden Rules
Where grey belt land comes forward for major residential development, policy GB8 of the NPPF (August 2026) requires affordable housing at the level set by an up-to-date plan policy — or 15 percentage points above the highest otherwise applicable requirement until then — necessary improvements to local or national infrastructure, and new or improved green space accessible to the public. Any viability appraisal for a grey belt case needs to carry these from the outset.
Building a defensible Grey Belt case
Cases that stand up share a pattern: a parcel-level Green Belt purposes assessment, clear evidence on containment and previously developed land, a heritage and landscape screening that addresses purpose (d), a golden-rules-compliant scheme, and the authority's own land supply position set out honestly.
- Parcel assessment against purposes (a), (b) and (d) individually.
- Evidence on previously developed land and existing built form.
- Heritage and landscape screening for setting effects.
- Affordable housing, infrastructure and green space commitments.
- The authority's five-year supply and Housing Delivery Test position.
Common questions
- Is there an official Grey Belt map?
- No. Grey Belt is a policy category rather than a mapped designation, so land must be assessed against the national definition parcel by parcel.
- Which Green Belt purposes matter for Grey Belt?
- Purposes (a) checking unrestricted sprawl, (b) preventing neighbouring towns merging, and (d) preserving the setting and special character of historic towns. Purposes (c) and (e) are not part of the test.
- Does Grey Belt status guarantee planning permission?
- No. It changes how Green Belt policy applies, but the Golden Rules in policy GB8, designated-area policies and the wider planning balance still have to be satisfied.
This assessment is an automated planning intelligence report based on available public data. It does not constitute planning, legal, valuation or other professional advice and does not guarantee that planning permission will be granted.