Extending your home in London is a fantastic way to add space, boost property value, and tailor your living environment to your lifestyle. But before you break ground, there’s one crucial aspect you absolutely can’t skip—permits. Understanding which permissions you need can save you from costly fines, stop-work notices, and months of delays.
In this friendly, step-by-step guide, we’ll walk you through everything you need to know about permits for a home extension in London. Whether you’re a first-time renovator or finally ready to expand your family home, this guide is your go-to resource.
Step 1: Check if You Need Planning Permission
Before you draw up plans or contact a builder, ask this critical question: Do I need planning permission?
In many cases, homeowners are surprised to learn that not all extensions require planning permission. If your extension falls under “Permitted Development Rights,” you may be able to proceed without formal approval. However, many London boroughs have strict guidelines, especially in urban and historic areas.
You’ll need planning permission if:
- Your extension is over 6m (terraced/semi-detached) or 8m (detached)
- You plan to build over 50% of your original garden area
- The extension faces a road or alters the street-facing façade
- You live in a Conservation Area or Listed Building
Tip: Always check with your local borough council. What’s allowed in Camden may differ from what’s allowed in Croydon.
Step 2: Understand Permitted Development Rights (PDR)
Permitted Development Rights (PDR) are rules that allow you to carry out certain types of building work without needing full planning permission. They’re designed to streamline minor home improvements.
Under PDR, you can:
- Build single-storey rear extensions within size limits
- Convert a loft into a livable room (with height/volume restrictions)
- Add side extensions (single-storey, within 3m wide)
However, these rights can be restricted or removed:
- In Conservation Areas
- For flats and maisonettes
- If an Article 4 Direction is in place
Tip: Always get a Lawful Development Certificate (LDC) from the council even if you believe your project qualifies under PDR. It proves your build was legal at the time.
Step 3: Apply for Building Regulations Approval
Even if your extension doesn’t need planning permission, it will need to comply with UK Building Regulations.
These rules ensure your build is:
- Structurally sound
- Energy efficient
- Safe in terms of fire exits, ventilation, drainage, etc.
You can apply through:
- Your local authority building control
- An approved private inspector
Expect regular site visits and inspections throughout your project.
Tip: Submit a Full Plans Application if your project is complex. It gives you formal approval before construction begins, reducing surprises later.
Step 4: Review Party Wall Requirements
Is your extension going to affect a shared wall with your neighbour? Then the Party Wall etc. Act 1996 comes into play.
You must serve a Party Wall Notice if:
- You’re building on or near the boundary
- You’re excavating within 3 to 6 metres of a neighbouring property
- You’re altering a shared wall (like inserting steel beams)
Your neighbour has 14 days to consent. If they dissent, a Party Wall Agreement (aka award) will be drawn up with a surveyor.
Tip: Always communicate early and openly with neighbours—it can save both time and legal headaches.
Step 5: Account for Conservation Areas and Listed Buildings
London is home to thousands of historic neighbourhoods. If your property is in a Conservation Area, World Heritage Site, or is Grade I, II, or II listed*, additional approvals apply.
In these cases:
- Planning permission is almost always required
- You may also need Listed Building Consent
- Design guidelines may limit materials, style, and size
Tip: Use your borough’s online planning map or contact the Conservation Officer before proceeding.
Homeowner’s Checklist for Home Extensions in London
| Task | Submit to the local council or hire an approved inspector |
|---|---|
| Check Planning Permission | Use the Planning Portal or contact your borough |
| Verify Permitted Development Rights | Confirm eligibility and get a Lawful Development Certificate |
| Apply for Building Regulations | Submit to local council or hire an approved inspector |
| Serve Party Wall Notice | Notify neighbours at least 2 months in advance |
| Check Conservation/Listed Status | Special permissions may apply |
Reliable Home Renovation Services Across London
Before starting any major work, it’s wise to consult professionals who offer Reliable Home Renovation Services Across London to ensure compliance and quality. They’ll help with planning, permits, and execution—saving you time, money, and stress.
For expert advice or a free quote, call us now at +44 7491 938445
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