UK Planning Permission Explained: What You Need, How to Apply, and Why It Takes So Long

You want to build an extension, convert your loft, or knock down a wall. Do you need planning permission? The answer is: it depends. The UK planning system is a labyrinth of rules, exceptions, and local variations that confuses homeowners and developers alike. Some work requires full planning permission, some falls under "permitted development" and needs no permission at all, and some requires only building regulations approval. Here is everything you need to know about UK planning permission — what you need, how to apply, how long it takes, and what to do if you are refused.

What Is Planning Permission?

Planning permission is approval from your local council to carry out building work or change the use of a property. It exists to ensure that development is appropriate for the area, does not harm neighbours, and complies with local and national planning policy.

Planning permission is separate from building regulations approval, which ensures that building work meets safety and construction standards (structural integrity, fire safety, insulation, drainage). Most projects require both.

What Needs Planning Permission?

You need planning permission for:

• New buildings (houses, flats, commercial buildings)
• Extensions (in most cases, though some are permitted development)
• Loft conversions (if they increase the height of the roof or add dormer windows)
• Outbuildings (sheds, garages, garden offices) over a certain size
• Changes of use (e.g., converting a house into flats, or a shop into a restaurant)
• Demolition (in conservation areas or for listed buildings)
• Fences and walls over 2 metres high (or 1 metre if next to a road)
• Satellite dishes and aerials over a certain size
• Work to listed buildings or in conservation areas (even minor alterations)

Permitted Development Rights

Many types of building work fall under permitted development rights, which means you do not need planning permission (though you may still need building regulations approval).

Single-storey rear extensions

You can build a single-storey rear extension without planning permission if:

• It extends no more than 6 metres from the rear wall (or 8 metres for detached houses)
• It is no higher than 4 metres at the highest point
• It covers no more than 50% of the land around the original house
• It is not on the side of the house facing a road

If your extension is larger, you may be able to use the larger home extension scheme, which allows extensions up to 8 metres (detached houses) or 6 metres (other houses) if neighbours do not object.

Loft conversions

You can convert your loft without planning permission if:

• The roof height does not increase by more than 150mm
• The volume added is no more than 40 cubic metres (terraced houses) or 50 cubic metres (detached and semi-detached houses)
• No part of the extension extends beyond the existing roof slope facing a road
• Materials are similar to the existing house

Outbuildings

You can build a shed, garage, or garden office without planning permission if:

• It is single-storey and no more than 4 metres high (or 3 metres if it has a pitched roof)
• It covers no more than 50% of the land around the original house
• It is not used as a separate dwelling
• It is at least 2 metres from the boundary (if over 2.5 metres high)

Other permitted development

• Porches up to 3 square metres and 3 metres high
• Driveways (unless they use non-porous materials, in which case you need planning permission to prevent flooding)
• Solar panels (on the roof, not on the front of the house facing a road)
• Fences and walls up to 2 metres high (or 1 metre if next to a road)

Exceptions

Permitted development rights are more restricted or removed entirely in:

• Conservation areas
• National parks and Areas of Outstanding Natural Beauty (AONBs)
• Listed buildings (any work requires listed building consent)
• Flats (permitted development rights are more limited)

Check with your local council's planning department before assuming your work is permitted development.

How to Apply for Planning Permission

If your work requires planning permission, you must submit an application to your local council.

Step 1: Check if you need permission

Use the government's Planning Portal (planningportal.co.uk) to check whether your work needs permission. The site has an interactive tool where you can input details of your project and get an answer.

Step 2: Prepare your application

You will need:

• Site location plan (a map showing the property and surrounding area, usually at 1:1250 or 1:2500 scale)
• Block plan (a plan showing the property boundaries, existing buildings, and proposed development, usually at 1:500 or 1:200 scale)
• Elevations and floor plans (drawings showing what the building will look like from each side, and the internal layout)
• Design and access statement (explaining the design and how it fits the area)
• Application fee (£206 for householder applications, £462 per dwelling for new homes)

Most people hire an architect or planning consultant to prepare the application, which costs £500–£2,000 depending on the complexity.

Step 3: Submit the application

You can submit online via the Planning Portal or by post to your local council. The council will:

• Validate the application (check that all documents are included)
• Consult neighbours (send letters to properties within 20–50 metres, depending on the type of development)
• Consult statutory bodies (e.g., highways authority, Environment Agency, Historic England)
• Assess the application against local and national planning policy

Step 4: Wait for a decision

The council must decide within:

• 8 weeks for householder applications (extensions, loft conversions, etc.)
• 13 weeks for major developments (10+ homes, or commercial buildings over 1,000 square metres)

In practice, many applications take longer due to delays, requests for more information, or the need to consult neighbours and statutory bodies.

How Councils Decide

Councils assess applications against planning policy, which includes:

• The National Planning Policy Framework (NPPF) — national government policy on development
• The local plan — the council's own planning policy, setting out where development should and should not happen
• Neighbourhood plans — community-led plans for specific areas
• Material considerations — factors like design, impact on neighbours, highways safety, and environmental impact

Neighbour objections

Neighbours can object to planning applications, and councils must consider objections. But councils are not bound by objections — they must decide based on planning policy, not popularity.

Common objections include:

• Loss of privacy (overlooking)
• Loss of light (overshadowing)
• Noise and disturbance
• Increased traffic
• Out of character with the area

Objections based on loss of property value, loss of view, or personal disputes are not material considerations and are ignored.

Approval rates

Around 88% of planning applications are approved (according to government data). Refusals are usually because the development:

• Harms the character of the area
• Harms neighbours' amenity (privacy, light, noise)
• Does not comply with local planning policy
• Is unsafe (e.g., poor access, flood risk)

What If You Are Refused?

If your application is refused, you have three options:

1. Revise and resubmit

You can revise your plans to address the council's concerns and submit a new application. This is often the quickest route, and many applicants succeed on the second attempt.

2. Appeal

You can appeal to the Planning Inspectorate, which is independent of the council. Appeals are decided by a planning inspector based on:

• Written representations (you and the council submit written statements, and the inspector decides without a hearing) — 80% of appeals
• A hearing (an informal meeting where you, the council, and objectors present your case) — 15% of appeals
• A public inquiry (a formal, court-like hearing with legal representation) — 5% of appeals, usually for major developments

Appeals take 6–12 months, and around 35% are successful. You can represent yourself, but many people hire a planning consultant or barrister.

3. Do nothing

If the refusal is final and you do not appeal, you cannot carry out the work. If you do, the council can issue an enforcement notice requiring you to undo the work, and you may face prosecution.

Costs

Planning permission is not cheap:

• Application fee: £206 for householder applications, £462 per dwelling for new homes, £96 for listed building consent
• Architect/consultant fees: £500–£2,000 for householder applications, £5,000–£20,000+ for major developments
• Appeal costs: £1,000–£5,000 for written representations, £5,000–£20,000+ for hearings and inquiries

Why Does It Take So Long?

Planning applications often take longer than the statutory 8 or 13 weeks because:

• Councils are understaffed — planning departments have been cut by 40% since 2010, and many councils have backlogs of hundreds of applications
• Consultations take time — councils must consult neighbours, statutory bodies, and parish councils, and wait for responses
• Applications are incomplete — many applications are missing documents or information, and the council must request more
• Political pressure — controversial applications (e.g., large housing developments) face political opposition and delays

Common Mistakes

1. Assuming you do not need permission

Many homeowners assume their work is permitted development when it is not, and carry out work without permission. If the council finds out, they can issue an enforcement notice requiring you to undo the work.

2. Not checking with neighbours

Even if you do not legally need to consult neighbours, it is good practice to discuss your plans with them. Neighbour objections can delay or derail applications.

3. Ignoring planning policy

Councils must follow planning policy, so it is important to understand what the policy says before applying. If your proposal clearly breaches policy, it is likely to be refused.

4. Doing work before permission is granted

You cannot start work until planning permission is granted. If you do, the council can issue a stop notice and require you to undo the work.

The Bottom Line

Planning permission is required for most building work that changes the external appearance or use of a property, but many extensions and alterations fall under permitted development rights and do not need permission. Applications are decided by local councils within 8 weeks (householder) or 13 weeks (major developments), but delays are common due to understaffing and backlogs. The average planning application costs £206 for householder applications, plus £500–£2,000 in architect fees. Neighbours can object, but councils decide based on planning policy, not popularity. Around 88% of applications are approved, but refusals can be appealed to the Planning Inspectorate, with appeals taking 6–12 months and a 35% success rate. Check the Planning Portal before starting work, consult neighbours, and hire a professional if your project is complex. The UK planning system is slow, bureaucratic, and frustrating, but it exists to protect the character of areas and the amenity of neighbours. If you follow the rules and understand the process, you can navigate it successfully.