Planning permission, explained

What planning permission actually is

Planning permission is your local council's formal approval for a change to a building or piece of land. It's the council saying "yes, you can build this here." Without it, when it's needed, you're building unlawfully, which the council can force you to undo, and which makes your home difficult to sell.

Planning permission controls what you build and how it looks. It's separate from Building Regulations, which control how it's built: structural safety, insulation, fire safety, drainage. Most projects need both.

Your council, your Local Planning Authority or LPA, is the body that decides your application. Every property in England sits within one LPA, and each LPA has its own published rules (called the Local Plan), its own officers, and its own track record of what it tends to approve and refuse.

When you need it, and when you don't

Some changes are big enough that the law requires planning permission. Others fall under what's called Permitted Development, a set of nationally defined rights that let you make certain changes without applying, provided you stay within set limits.

You usually don't need planning permission for:

• Single-storey rear extensions within size limits (typically up to 4m for detached houses, 3m for others), provided you're not in a conservation area or listed building
• Loft conversions that don't extend beyond the existing roof plane and stay within volume limits
• Small outbuildings, sheds, and garden rooms within size and height limits
• Internal alterations that don't change the building's use
• Replacement windows in non-conservation areas
• Driveways using porous materials

You almost always need planning permission for:

• Two-storey extensions
• Anything in a conservation area, on a listed building, or within a National Park
• Front extensions
• Changes of use (for example, converting a garage to a habitable room, a house to flats, or a commercial property to residential)
• New buildings of any kind
• Anything that affects a tree with a Tree Preservation Order

Even if you don't need planning permission, you might need other consents. Building Regulations approval, Listed Building Consent, Conservation Area Consent, or a Lawful Development Certificate to formally confirm you didn't need permission. These are separate processes, separate fees, and separate decisions.

If you're not sure where your project sits, the safest first move is to find out what your specific property is allowed to do. Restrictions vary street by street; your neighbour's loft conversion being approved doesn't mean yours will be.

How to apply

The process is the same across England, even though each council interprets the rules slightly differently.

1. Confirm what you're allowed to do. Check whether your property is in a conservation area, near a listed building, covered by an Article 4 direction (which removes Permitted Development rights in specific areas), in a flood zone, or affected by other constraints. These materially change what you can build and how likely it is to be approved.
2. Consider pre-application advice. Most councils offer informal feedback on your proposal for a fee, typically £100 to £600 for a householder project. You submit a sketch and the council's planning officer tells you whether they think it'll get approved and what they'd want changed. It's not binding, but it's usually cheaper than a refused application, and a refusal costs you the full application fee plus your architect's time.
3. Appoint an architect or designer. You'll need professional drawings: existing and proposed floor plans, elevations, a site location plan, and a block plan. RIBA-chartered architects, CIAT chartered architectural technologists, and architectural designers all do this work at different price points (roughly £1,000 to £6,000 for a typical householder project). Local knowledge of your specific council matters; ask whether they've worked in your area before.
4. Submit the application. Most applications go through the Planning Portal or directly to your council. The current householder application fee is £548, with a Planning Portal processing fee of around £91 on top. A Lawful Development Certificate is £272.
5. Wait. Statutory determination is 8 weeks for householder applications (13 for larger schemes). During this time, neighbours are notified, the application appears on the council's website, and a planning officer reviews it against local and national policy. The officer might contact you for changes; that's normal and usually a good sign.
6. Get the decision. You'll receive either an approval (usually with conditions), a refusal, or a withdrawal. Approval with conditions is the most common outcome. Read the conditions carefully; some have to be formally discharged before you can start work.

What affects your chances of approval

National approval rates run around 86% for householder applications. But the average hides enormous variation. Two properties on different streets in the same town can have very different odds, depending on factors that are specific to the location, the council, and the project.

The property itself. A property in a conservation area, on a listed building, in a Green Belt, in a flood zone, or within a National Park starts from a more restrictive baseline. The same extension that's straightforward in a postwar suburb might be refused outright on a Victorian terrace in a conservation area.

The council. Approval rates vary by tens of percentage points between LPAs. Some councils are more permissive on rear extensions; others scrutinise them carefully. Some have published design guides that effectively define what they'll approve. Past decisions are the clearest signal of what a council is likely to do next.

The neighbourhood. Even within the same council, individual streets and wards have different patterns. A heavily extended street tends to see more approvals on the same kind of work; an area with strict character protections sees more refusals.

The project type. Single-storey rear extensions have high approval rates nationally. Loft conversions are slightly lower. Two-storey side extensions and front extensions face more scrutiny. Dormers vary substantially by council; some approve them as standard, others refuse most of them.

The design. This is the part you and your architect control. The same project drawn well, matching materials, respecting the building's character, paying attention to neighbour amenity, has a substantially better chance than the same project drawn badly. Most refusals come down to design choices that could have been resolved at the drawing stage.

Specific risk factors that come up repeatedly in refusals:

• Loss of light to neighbouring windows
• Overlooking neighbouring gardens or windows
• Out-of-character materials or proportions
• Loss of parking
• Impact on protected trees
• Overdevelopment of the plot
• Effect on the setting of a listed building or conservation area

A good application addresses these in the design and supporting documents before the officer has to raise them.

After approval

Approval isn't the end of the process.

Discharge any pre-commencement conditions before starting work. Some conditions, typically materials, drainage, construction management, must be formally signed off by the council before any work begins. Starting work before discharging a pre-commencement condition can invalidate the whole permission.

Apply for Building Regulations approval if you haven't already. This is a separate process focused on construction standards. Most building work needs it, even if it didn't need planning permission.

Serve Party Wall Notices if your work is close to a neighbouring building. The Party Wall etc. Act 1996 requires at least 2 months' notice for foundation excavation within 3 metres of a neighbour's building (or 6 metres for deep foundations), and for cutting into shared walls.

Time limit. Planning permission lasts 3 years from the date of approval. If you don't make a material start within that period, it expires and you'd need to apply again, and policies may have moved on.

Keep your paperwork. Your decision notice, conditions, Building Regulations Completion Certificate, and any Party Wall agreements should all be kept indefinitely. Your solicitor will ask for them when you sell.

If your application is refused

You have two options.

Revise and resubmit. If the refusal points to specific issues, a design feature, a materials choice, a relationship with neighbouring properties, most architects will recommend addressing those and submitting a revised scheme. The council will usually waive the application fee within 12 months if the project is broadly similar.

Appeal to the Planning Inspectorate. Appeals take 6 to 12 months and have roughly a 30 to 35% success rate for householder applications. They're worth pursuing where the council's reasoning is clearly inconsistent with policy or with what they've approved on similar projects nearby, and not worth pursuing where the refusal is reasonable on its face.

In most cases, revising and resubmitting is faster and cheaper. Appeals make sense when you've genuinely been refused unfairly.

Common things people get wrong

• Assuming a neighbour's approval means yours will be approved. Restrictions vary plot by plot. What was allowed next door three years ago might not be allowed at your address today.
• Treating Building Regulations and planning permission as the same thing. They're separate. You can need one without the other, and you often need both.
• Starting work before discharging pre-commencement conditions. This invalidates the entire permission.
• Missing the 3-year time limit. Permissions expire. If your plans have stalled, check the date.
• Not serving Party Wall Notices in time. You need 2 months. Leaving it to the week before your builder starts means either delaying the build or breaking the law.
• Confusing "approved" with "anything goes." Permission usually comes with conditions. Read them.

What's actually decided where

Quick reference

Related guides

• Permitted development rights — what you can build without a full planning application.
• Article 4 directions — where your council has removed permitted development rights.
• The planning and build process — what to expect from first idea to finished work.
• Planning permission costs — application, professional and building costs, with current figures.
• Building regulations — how a project is signed off as safe, and the certificate you'll need when you sell.