One of the most common questions homeowners ask before starting an extension is: “Do I need planning permission?” The answer isn’t always straightforward. Sometimes you can build under permitted development rights – other times you’ll need full permission from your local council.
In this guide, we’ll break down everything you need to know about planning permission, permitted development, and the steps to take to avoid costly mistakes.
Why Planning Permission Matters
Planning permission exists to ensure that new buildings and extensions:
Respect the character of the local area,
Protect neighbours’ rights to light and privacy,
Meet safety and environmental standards,
Fit within your property’s boundaries and use.
Failing to secure permission when it’s required can lead to:
Enforcement notices,
Costly redesigns,
Fines or legal action,
Problems selling your property in future.
💡 For peace of mind, explore our Planning page, where we explain how we guide you through the process
What Is Permitted Development?
Permitted development (PD) rights allow homeowners to extend their property without applying for full planning permission – as long as the extension meets certain rules.
For example, you may not need full planning permission if your extension:
Does not extend beyond a set number of metres from the original house,
Is not higher than the existing roof,
Uses similar materials to the original property,
Does not take up more than 50% of the land around the original house.
However, these rules vary depending on your property type, conservation area restrictions, and previous extensions. That’s why it’s essential to get expert advice.
Extensions That Usually Require Planning Permission
Not all projects qualify for permitted development. You’ll likely need planning permission if you’re building:
A Double Storey Extension that extends too far into the garden,
A Wraparound Extension that exceeds PD limits,
Any extension on a listed building,
Projects in conservation areas,
Large-scale developments that alter the character of your property.
If you’re unsure, speak to us – we’ll check your plans against current rules and guide you through the application process.
The Role of Neighbours in Planning
Neighbours are often consulted when you apply for planning permission. Their main concerns usually involve:
Loss of light,
Overlooking or privacy,
Noise and disruption during construction.
By working with an experienced design and build company, you can design extensions that minimise objections. At Reltic Extend, we take this into account from the start – helping you keep good neighbourly relations.
Regional Considerations: London & Surrey
Planning rules can vary by local council. Here’s a quick look at how it often plays out:
North London – period homes often face stricter planning requirements.
South London – wraparounds and larger rear extensions may need permission.
East London – compact homes may benefit from PD rights.
West London – double storey projects often require full applications.
Surrey – larger plots sometimes make permission easier to secure.
Each council has its own approach, so expert guidance is essential.
Common Mistakes to Avoid
Homeowners often run into planning issues because they:
Assume PD rights apply without checking,
Submit incomplete applications,
Fail to account for height restrictions,
Forget about listed building or conservation restrictions.
Our How We Work approach ensures every box is ticked before construction begins.
How Reltic Extend Simplifies the Process
At Reltic Extend, we take the stress out of planning by:
Checking your design against PD rights,
Handling full planning applications where required,
Liaising with local councils on your behalf,
Advising on cost-effective solutions if changes are needed.
For full reassurance, see our Warranty and Insurance page – we stand behind every project we deliver.
Final Thoughts
Knowing whether you need planning permission – or whether your project qualifies under permitted development – is the key to starting your extension the right way. With the right guidance, you can save time, avoid stress, and move forward confidently.
Ready for a complete extension service?
Not sure if your project needs planning permission?
👉 Visit our Planning page for expert guidance, or use our Cost Calculator to start budgeting your extension today.
With Reltic Extend, you’ll always have the clarity and support you need from start to finish.
