What is planning permission?

Planning permission is the system that decides what you can build, where, and how it looks.

Why planning permission exists

The UK planning system began in 1947 (Town and Country Planning Act 1947) to rebuild Britain after World War II and prevent uncontrolled development.¹ Before that, anyone could build almost anything anywhere. The new system gave local authorities control over what gets built in their area.

Planning permission balances competing interests. You want to extend your house. Your neighbour wants their view and sunlight protected. The council wants to ensure new development fits the area, doesn't overload infrastructure, and protects heritage sites or green spaces. Planning permission is the mechanism that weighs these factors.

When you need planning permission

You need planning permission if your work is "development" and not covered by permitted development rights. Development means building work, engineering operations, or changing the use of land or buildings.²

Common examples that need permission:

• New buildings — Houses, flats, commercial buildings, industrial units
• Large extensions — Rear extensions over permitted development limits (3m for terraced/semi-detached, 4m for detached)³
• Front extensions — Almost always need permission (front is visible from the street)
• Loft conversions — If they change the roof shape significantly or add dormer windows facing the road
• Outbuildings — If over 2.5m high (or 4m with dual-pitched roof), or within 2m of a boundary and over 2.5m high
• Changes of use — Converting a house to flats, a shop to a restaurant, residential to commercial
• Listed buildings — Any alterations (internal or external) to a listed building need listed building consent
• Conservation areas — Stricter rules apply to work visible from the street

When you don't need planning permission

Permitted development rights allow certain building work without needing full planning permission. These rights come from the Town and Country Planning (General Permitted Development) Order 2015 in England.⁴

Common work that doesn't need permission (if within size limits):

• Small rear extensions (up to 3m or 4m deep, depending on house type)
• Single-storey rear extensions under 3m high
• Small garden sheds and outbuildings
• Internal alterations (unless it's a listed building)
• Replacing windows with similar styles (unless listed or in a conservation area)
• Driveways using permeable materials (or with soakaways)

Important: Permitted development rights have conditions. If you exceed any size limit, height restriction, or proximity rule, the whole project needs full planning permission. Read more in our guide to permitted development rights.

How the planning system works

Planning permission is decided by your local planning authority (usually your council). They assess applications against:

• Local planning policy — Your council's development plan (what they want built, where, and how it should look)
• National planning policy — The National Planning Policy Framework (NPPF) sets broad principles⁵
• Material considerations — Impact on neighbours, traffic, heritage, environment, design quality

Planning officers assess the application and recommend approval or refusal. For major applications or controversial projects, the planning committee (elected councillors) makes the final decision. For smaller householder applications, officers often decide under delegated powers.

Standard decision time

8 weeks for householder applications, 13 weeks for major developments

Typical householder application fee (England)

£206 (as of April 2026)

Permission duration

3 years from approval date (must start work within this period)

Appeal success rate (England 2024-25)

~33% of planning appeals succeed⁶

What happens if you build without permission

Building without planning permission (when you needed it) is a planning breach. Your local planning authority can take enforcement action:

• Enforcement notice — Orders you to undo the work or apply for retrospective permission
• Stop notice — Halts work immediately (rare, used for serious breaches)
• Prosecution — Ignoring an enforcement notice is a criminal offence. Fines up to £20,000 in magistrates' court, unlimited in crown court

Time limits apply. The council has four years from substantial completion to take action for building work (extensions, new buildings). For changes of use, they have ten years. After these periods, the breach becomes immune from enforcement (but this is risky to rely on).

Can you apply retrospectively? Yes. You can submit a planning application after completing work. The council assesses it the same way as if you'd applied beforehand. If they refuse, you must undo the work or face enforcement. Retrospective applications have the same fee as standard applications.

Different types of planning permission

Several routes exist depending on your project:

• Householder planning permission — For extensions, outbuildings, alterations to houses
• Full planning permission — For new buildings, major extensions, changes of use. Includes detailed plans and drawings
• Outline planning permission — Establishes whether a site is suitable for development before detailed design. Common for new housing estates
• Reserved matters — Detailed approval after outline permission (design, landscaping, access, scale)
• Listed building consent — Separate permission needed for any work affecting a listed building's character
• Certificate of lawfulness — Confirms existing use or completed work is lawful (no permission needed). Alternative to retrospective permission

Planning permission vs building regulations

Planning permission and building regulations are separate. You often need both.

• Planning permission — Whether you can build it (location, size, appearance, impact)
• Building regulations — How to build it safely (structure, fire safety, insulation, ventilation)

A project can have planning permission but fail building regulations inspection. Conversely, work that meets building regulations might lack planning permission. Check both before starting. Building control is a separate department (or an approved inspector for larger projects).

Next steps

If you're planning building work:

1. Check if you need planning permission (use the Planning Portal's interactive tool)
2. Review your council's local plan to understand what's likely to be approved
3. Consider pre-application advice from your planning authority (£50-200, helps avoid refusal)
4. Submit a planning application if required. Read our guide on how to apply for planning permission
5. Check building regulations requirements separately

Last reviewed: 14 June 2026