Conservation area


Version: 1.1.1 - published 2022-06-09


This specification defines the format for how a planning authority should provide information about conservation areas as data.

This technical specification is accompanied by guidance, examples and other tools providing feedback to data providers.

Status of this specification

This is a draft specification, following the standards for planning data process [process]. The contents of this specification are currently under development, and liable to change based on feedback.

This specification is intended to be published as one of a number of official data standards for the provision of planning data under the proposed Levelling-up and Regeneration bill [LURB], as introduced to parliament on 19 May 2022.

Warning It is inappropriate to cite this document as other than a work in progress.

Comments and feedback on this specification may be provided on the GitHub issue [TBD] or sent to digitalland@communities.gov.uk.


As well as sections marked as non-normative, all authoring guidelines, diagrams, examples, and notes in this specification are non-normative. Everything else in this specification is normative.

The key words MAY, MUST, NOT, and SHOULD in this document are to be interpreted as described in [RFC2119] when, and only when, they appear in all capitals [RFC8174] as shown here.

Documentation page

A data provider MUST provide a list of all of the conservation areas within its jurisdiction on a documentation page.

The documentation page MUST be accessible as HTML from a public URL.

The documentation page MUST be clearly owned and operated by the data provider. Where the data provider is a local authority or other public body, the web page MUST be on a .gov.uk domain.

The documentation page MUST include:



The conservation-area data MUST be published in an open data format.

The data MUST contain at least one entry for each conservation-area.

Each entry MUST containing the following fields:

  • reference
  • name — the official name for the conservation area
  • documentation-url — an optional URL of a document providing the authoritive source of the boundary. For example a PDF containing a map of the area indicated with a red-line boundary.
  • geometry
  • notes
  • organisation
  • entry-date
  • start-date
  • end-date


The conservation-area-document data MUST be published in an open data format.

The data MUST contain at least one entry for each conservation-area-document.

Each entry MUST containing the following fields:

  • reference
  • conservation-area — the reference for the conservation area this document is about
  • name — the title of the conservation area document
  • documentation-url — the URL of the webpage citing the document
  • document-url — the URL of the document
  • document-type — the type of the conservation area document which MUST be one of the following values: 'area-appraisal', 'notice', or blank
  • notes
  • organisation
  • entry-date
  • start-date
  • end-date



Dates MUST conform to [ISO8601] following the Open Standards for government guidance on formatting dates and times in data [formatting-dates-and-times-in-data].

A date value SHOULD be blank if it is unknown. The date may just contain the year 'YYYY' if only the year is known, or 'YYYY-MM' if only the year and month is known.


The boundary for the conservation area as a single POLYGON or MULTIPOLYGON value.

In all cases all points MUST be either in the [WGS84] (EPSG::4326) or [ETRS89] (EPSG::4258) coordinate reference system following the Open Standards for government guidance on the exchange of location points [exchange-of-location-point].

Positions calculated by the WGS84 and ETRS89 systems currently deviate by less than half a metre for points within England. Boundaries provided by this dataset are intended to be used as an index. Survey data SHOULD be used where more precision is needed.


The reference identifies the entity within a data provider.

A URI for the entity may be constructed by a combination of the reference with a IRI prefix value, or be provided in an optional URI field.

A reference value MUST be suitable as the reference part of a [CURIE] identifier.

A reference MUST be unique within the dataset; it MUST NOT have been used by the data provider to identify a different entity.

A reference SHOULD be persistent. A reference SHOULD be used by the data provider to identify the same entity in the future.

The reference MAY be used in other contexts to refer to the entity. For example, the reference may be used to construct a URL to a web page with more information about the Conservation area.

A reference SHOULD be short and meaningful to a user. For example, the reference may be used to refer to a Conservation area when completing a form, or contacting a call centre.


All text fields MUST be encoded in UTF-8 [RFC3629] following the Open Standards for government guidance on encoding characters [encoding-characters].

Historical data

Entries SHOULD be ordered by the entry-date, with older entries appearing before later entries.

The end-date field should be used to indicate when an entity is no longer applicable. Entries SHOULD NOT be removed from the data except to correct a mistake, or for the purposes of redacting personal or sensitive information.

Open data formats

Data which does not contain geospatial information (a point or geometry field) MUST be provided as (CSV).

Geospatial data MUST be provided in at least one of the following open data formats:

The preferred format for representing geospatial data is Comma Separated Value (CSV) with the geometry and point fields containing Well Known Text [WKT].

The data MAY also be provided in other data formats such as a [ZIP] archive containing a collection of ESRI shapefiles [Shapefile], a Mapinfo TAB [TAB] file.

Security and privacy considerations

The data MUST NOT contain any personal or sensitive information, unless explicitly required by this specification, or legislation.

There is a risk of people's names or other personally identifiable information appearing in the data, in particular notes, description and other text fields. It is the responsibility of the data provider to review and redact such information before publication. The for example, the [OGL3] licence does not


This document is © Crown Copyright and available under the Open Government Licence version 3 licence.


The specification builds upon work from the local digital pathfinding local planning authorities, the Reducing Invalid Planning Applications (RIPA) and Back Office Planning System (BOPS) projects.


Normative references

Key words for use in RFCs to Indicate Requirement Levels. IETF Best Current Practice. https://tools.ietf.org/html/rfc2119
Ambiguity of Uppercase vs Lowercase in [RFC2119] Key Words. IETF Best Current Practice. https://datatracker.ietf.org/doc/html/rfc8174
UTF-8, a transformation format of ISO 10646. IETF Internet Standard. https://datatracker.ietf.org/doc/html/rfc3629
Common Format and MIME Type for Comma-Separated Values (CSV) Files. IETF Informational. https://datatracker.ietf.org/doc/html/rfc4180
The GeoJSON Format. Proposed Standard. https://datatracker.ietf.org/doc/html/rfc7946
Date and Time on the Internet: Timestamps. IETF Proposed Standard. https://datatracker.ietf.org/doc/html/rfc3339
Metadata Vocabulary for Tabular Data. W3C Recommendation. https://www.w3.org/TR/2015/REC-tabular-metadata-20151217/
Model for Tabular Data and Metadata on the Web. W3C Recommendation. https://www.w3.org/TR/2015/REC-tabular-data-model-20151217
Geography Markup Language (GML). Open Geospatial Consortium standard (ISO 19136-1:2020). https://www.ogc.org/standards/gml
Open Government Licence for public sector information. Version 3. https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/
Crown copyright. Section 163 of the Copyright, Designs and Patents Act 1988 as works made by officers or servants of the Crown in the course of their duties. https://www.nationalarchives.gov.uk/information-management/re-using-public-sector-information/uk-government-licensing-framework/crown-copyright/

Informative references

Levelling-up and Regeneration Bill. Originated in the House of Commons, Session 2022-23. https://bills.parliament.uk/bills/3155
Department for Levelling Up, Housing and Communities planning data standards design process (under development)
CURIE Syntax 1.0 A syntax for expressing Compact URIs. W3C Working Group Note. https://www.w3.org/TR/2010/NOTE-curie-20101216/
Persistent resolvable identifiers. Open Standards for Government. https://www.gov.uk/government/publications/open-standards-for-government/persistent-resolvable-identifiers
Formatting dates and times in data. Open Standards for Government. https://www.gov.uk/government/publications/open-standards-for-government/date-times-and-time-stamps-standard
Publishing government documents. Open Standards for Government. https://www.gov.uk/government/publications/open-standards-for-government/viewing-government-documents
Exchange of location point. Open Standards for Government. https://www.gov.uk/government/publications/open-standards-for-government/exchange-of-location-point
Tabular data standard. Open Standards for Government. https://www.gov.uk/government/publications/recommended-open-standards-for-government/tabular-data-standard
Using CSV file format. Central Digital and Data Office guidance. https://www.gov.uk/guidance/using-csv-file-format
CSV on the Web: A Primer. W3C Working Group Note. https://www.w3.org/TR/tabular-data-primer/
WGS84 - World Geodetic System 1984, used in GPS. EPSG Geodetic Parameter Dataset. https://epsg.io/4326
GDAL. Open Source Geospatial Foundation. https://gdal.org/
ESRI Shapefile format. https://en.wikipedia.org/wiki/Shapefile

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