If you're thinking about a home extension in the UK, one of the first questions that comes up is: "Do I need planning permission?"
It's a vital step that can make or break your project. Many extensions can be built under Permitted Development Rights (PDR), but not all. Getting this wrong could mean fines, delays, or even being forced to take your extension down.
At Buildaway, we've helped homeowners across London, Kent, and Essex navigate the planning system and build extensions that add real value. Here's what you need to know.
1. What Is Planning Permission?
Planning permission is official approval from your local council to make changes to your property. It ensures that extensions:
- Fit with the local environment
- Don't negatively impact neighbours
- Comply with building regulations and safety standards
Without it, your project could be stopped mid-build.
2. Do All Extensions Need Planning Permission?
Not always. Thanks to Permitted Development Rights (PDR), many UK homeowners can extend without applying for full planning permission — provided the extension meets specific rules.
You usually DON'T need planning permission if:
- It's a single-storey rear extension within size limits (max 6m for semi-detached/terraced, 8m for detached)
- The extension is not higher than the highest part of the existing roof
- Materials match the look of your home
- It doesn't extend beyond the front of the property
You WILL need planning permission if:
- Your property is in a conservation area or listed building
- The extension exceeds permitted size limits
- You're building a double-storey extension
- It impacts your neighbour's privacy or blocks light
3. Common Mistakes Homeowners Make
We've seen plenty of UK homeowners get caught out by:
- Assuming PDR applies everywhere — it doesn't in conservation areas or flats
- Forgetting about height restrictions — even small roof changes can trigger permission
- Not considering neighbours — objections can delay or block projects
- Skipping drawings and documentation — councils require detailed plans
4. How Long Does Planning Permission Take?
On average, local councils take 8–12 weeks to process applications. Larger or more complex builds may take longer, especially if neighbours raise objections.
Tip: Submit detailed, accurate drawings with your application to avoid delays.
5. Planning Permission vs. Building Regulations
These are not the same.
- Planning permission = external look, size, and impact of your extension
- Building regulations = safety, energy efficiency, drainage, and structural standards
Even if you don't need planning permission, you still need to comply with building regulations.
6. FAQs on Planning Permission for UK Extensions
Do I need planning permission for a conservatory?
Most small conservatories fall under PDR, but larger ones may require approval.
What happens if I build without permission?
The council can issue an enforcement notice, and in worst cases, force you to remove the extension.
Can I appeal if my planning application is refused?
Yes, homeowners can appeal within 6 months, but it's easier to avoid mistakes from the start.
Do loft conversions need planning permission?
Most don't (they're covered by PDR), unless the design significantly alters the roof shape or height.
How Buildaway Makes Extensions Simple
Dealing with councils and paperwork can feel overwhelming, but we manage the entire process. With Buildaway, you get:
- Expert advice on whether your project needs permission
- Full drawings and documentation for smooth applications
- Communication with local councils on your behalf
- High-quality design and build with clear timelines
- A workmanship warranty for peace of mind
Whether you're planning a rear extension, double-storey addition, or full refurb, we'll make sure you're covered legally — and deliver results that add real value.