Free tool

What planning constraints affect your property?

Check conservation areas, listed buildings, Article 4 directions, flood zones, green belt, National Parks, National Landscapes and other planning constraints from a postcode.

What is the property's postcode?

England only, for example BS1 6SU. The lookup starts at the centre of the postcode and looks 75 m around it.

Why this matters
Planning constraints are the designations and zones that change what can be built without a planning application, or how an application is decided: conservation areas, Article 4 directions, listed buildings, World Heritage Sites, National Landscapes, National Parks, green belt, Sites of Special Scientific Interest, tree preservation orders, scheduled monuments, registered parks and gardens, and flood zones. The centre of a postcode comes from the Office for National Statistics' Postcode Directory. A large property, or a boundary running close by, can put a house on the other side of a line from its postcode's centre, so the checker reports what is close as well as what covers the centre.

About this tool

Enter a postcode. The checker looks up the planning constraints that change what you can build there, draws what it finds on a map of the surrounding 75 metres, and marks each one found, close by, not found in the available data, or no data where the council has not supplied it. It then explains what each one means for extensions, windows, roofs and outbuildings.

Jurisdiction
England
Law checked
29 September 2026
Tool version
1.2

Made and maintained by Parallel Architecture, a director-led architectural design practice working from Bristol and Brighton. Each rule is checked against the legislation itself and cited where it is applied. How we write the guides and tools.

General guidance on the law in England from the answers you enter, not advice on your project. Website terms.

What this checker is doing

Your postcode goes from this website to the public data services named below and back. It is not stored, and your browser does not contact those services itself.

  1. It finds the centre point of the postcode from the Office for National Statistics' Postcode Directory, through postcodes.io.
  2. It asks the government's planning data platform which of these cover that point, and which lie within about 75 metres of it: conservation areas; Article 4 directions, where the council has removed permitted development rights, the rights to build or make changes without a planning application; World Heritage Sites; National Landscapes; National Parks; green belt; Sites of Special Scientific Interest, protected for their wildlife or geology; tree preservation zones, areas where a tree preservation order protects the trees; scheduled monuments; and registered parks and gardens.
  3. It lists the listed buildings within about 75 metres, from Historic England's National Heritage List, so you can see whether your house is one of them.
  4. It checks the Environment Agency's Flood Map for Planning for Flood Zones 2 and 3, where a planning application needs a flood risk assessment for the site.
  5. It checks whether your council has given the national platform its own data on conservation areas and Article 4 directions. Many have not. Where the council has not, the checker says "no data" rather than "no", and points you to the council's own map.
  6. It draws what it found as a map around the postcode, from the boundaries in the same data, with the 75 metres it searched. The map is drawn on this page from those figures: no map service is asked for anything.
  7. It explains what each one changes and, for conservation areas and listed buildings, which permission common works need.

Data

  1. Planning data platform, Ministry of Housing, Communities and Local Government: planning.data.gov.uk. Contains public sector information licensed under the Open Government Licence v3.0.
  2. National Heritage List for England, through the planning data platform. © Historic England 2026. Contains Ordnance Survey data © Crown copyright and database right 2026.
  3. Flood Map for Planning, Environment Agency. © Environment Agency copyright and/or database right 2026.
  4. Postcode locations from postcodes.io, using the ONS Postcode Directory. Contains OS data © Crown copyright and database right 2026. Contains Royal Mail data © Royal Mail copyright and database right 2026. Contains National Statistics data © Crown copyright and database right 2026.

Key rules

  • A conservation area is an area the council has designated for its special architectural or historic interest (Planning (Listed Buildings and Conservation Areas) Act 1990, section 69).
  • Conservation areas, National Parks, National Landscapes, the Broads and World Heritage Sites are article 2(3) land, where permitted development is narrower (General Permitted Development Order 2015, article 2(3) and Schedule 1, Part 1).
  • On article 2(3) land, a side extension, a rear extension of more than one storey, a dormer or other roof enlargement and external cladding need planning permission (GPDO 2015, Schedule 2, Part 1, paragraphs A.2 and B.1(f)).
  • The larger home extension scheme, prior approval for a deeper single-storey rear extension, is not available on article 2(3) land or a Site of Special Scientific Interest (GPDO 2015, Schedule 2, Part 1, paragraph A.1(g)).
  • Demolishing a building in a conservation area needs planning permission, and doing it without is an offence (Town and Country Planning Act 1990, section 196D).
  • Work to a tree in a conservation area needs six weeks' notice to the council, or its consent if the tree has a tree preservation order (Town and Country Planning Act 1990, section 211).
  • An Article 4 direction removes named permitted development rights in an area or for a site, so work it covers needs a planning application (GPDO 2015, article 4).
  • The national dataset of Article 4 directions is incomplete, so finding none there does not show that none applies: the council's own list is the reliable source.
  • Listed building consent is needed to demolish a listed building, or to alter or extend it in any way that affects its character, inside or out, at every grade (Listed Buildings Act 1990, section 7).
  • Listed building consent has no fee, and works without it are a criminal offence (Listed Buildings Act 1990, section 9).
  • The permitted development right for outbuildings does not apply within the curtilage of a listed building (GPDO 2015, Schedule 2, Part 1, paragraph E.1(g)).
  • Designation as a conservation area does not list the houses in it: listing is a separate designation, with its own consent (Listed Buildings Act 1990, sections 7 and 69).
  • In Flood Zone 2 or 3 of the Environment Agency's Flood Map for Planning, a planning application needs a flood risk assessment for the site.
  • Green belt is not article 2(3) land, so it does not narrow permitted development, but a planning application for an extension there is judged against green belt policy.

Sources: the Acts and Order named, and this site's guides to living in a conservation area, Article 4 directions and listed building consent.

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