Planning explained
The designations and terms that decide what you can build — each in plain English, with what it is, what it means for your project, and where it comes from. These are the deep explainers; the glossary is the quick index.
Article 4 direction
An Article 4 direction is a decision by a council to remove specified permitted development rights in a defined area. Work that would normally need no planning application — certain extensions, alterations, even paving or basements — requires full permission where one applies. They are address-specific and are the single most common surprise for homeowners.
Read the explainer →Conservation area
A conservation area is an area designated for its special architectural or historic interest, whose character the council has a duty to preserve or enhance. Inside one, the design bar for external changes rises, some permitted development rights are restricted, and heritage carries great weight in decisions.
Read the explainer →Listed building
A listed building is one on the national list of buildings of special architectural or historic interest. Works that affect its character — inside or out — need listed building consent, which is separate from planning permission and carries criminal liability for unauthorised work.
Read the explainer →Permitted development
Permitted development is building work granted automatic planning permission by the General Permitted Development Order, within strict limits on size, height and siting. Most small householder projects — many extensions, loft dormers, outbuildings and driveways — use this route to avoid a planning application. Designations like conservation areas and Article 4 directions narrow or remove it.
Read the explainer →Article 2(3) land
Article 2(3) land is land where permitted development is automatically more restricted: conservation areas, National Parks, the Broads, National Landscapes (AONBs) and World Heritage Sites. Several permitted development classes — including Class B roof additions — do not apply at all on article 2(3) land, which is why a loft dormer permitted two streets away can need a full application inside a conservation area.
Read the explainer →Tree preservation order (TPO)
A tree preservation order protects specific trees or woodlands. Cutting down, topping, lopping or uprooting a protected tree needs the council’s written consent, and development near one is expected to protect its roots. Breaching a TPO is a criminal offence.
Read the explainer →Green Belt
The Green Belt is land designated to check urban sprawl by keeping land permanently open. Most new building is restricted, but extensions to existing houses are allowed where they are not disproportionate to the original dwelling. Openness is the test that runs through every decision.
Read the explainer →Flood risk zone
Flood risk zones are Environment Agency areas describing the probability of flooding (Zones 1, 2 and 3). Development in the higher zones needs a flood risk assessment, and some types face sequential and exception tests. For most householder extensions the main effect is a requirement to assess and manage flood risk.
Read the explainer →Lawful development certificate
A lawful development certificate is a formal council confirmation that work is lawful — either because it is permitted development, or because it has existed long enough to be immune from enforcement. It is not compulsory, but it is valuable at resale to prove an extension or loft needed no planning permission.
Read the explainer →