How to Navigate Local Planning Policy for Home Extensions in Greater London: A Borough-by-Borough Guide

Planning an extension in London can feel like stepping into a maze of rules, exceptions, and local quirks. National permitted development rights provide a baseline, but London’s 32 boroughs often add their own layers of control — from conservation areas and Article 4 Directions to borough-specific design guides.

This guide will help you understand what’s allowed where, what the most common pitfalls are, and how to prepare an application that has the best chance of success.

What You’ll Learn in This Guide

• The difference between permitted development rights and planning permission.

• How Article 4 Directions change the rules.

• The local planning policies of major London boroughs like Camden, Kensington & Chelsea, Richmond, and more.

• Common reasons why applications get refused.

• A step-by-step checklist to prepare for your extension project.

Understanding the Basics

1. Permitted Development (PD)

PD rights allow certain works — such as modest rear extensions, loft conversions, or porches — without submitting a full planning application. They come with strict limits on size, height, and materials. Go beyond these, and you’ll need planning permission.

2. Article 4 Directions

Boroughs can remove PD rights in specific areas (often conservation zones or for basements) using Article 4 Directions. If your home is covered, even small changes like replacing windows or converting a loft may require permission.

3. Local Plans & Design Guides

Each borough publishes Local Plan policies and Supplementary Planning Documents (SPDs). These add detail on extensions, materials, garden space, basements, and daylight/sunlight standards. Officers use these documents to judge applications.

4. Pre-Application Advice

Many councils offer paid or free pre-application advice. It’s not binding, but it helps flag likely objections early and can save you time and money.

Borough-by-Borough Highlights

Kensington & Chelsea (RBKC)

• Key issue: Basements. PD rights for basements are removed borough-wide.

• Other considerations: Tight conservation controls and a high concentration of listed buildings.

• Tip: Budget for structural and flood-risk reports. Always assume you’ll need a full planning application.

Camden

• Key issue: Conservation areas and Article 4 Directions.

• Guidance: Camden publishes detailed SPGs on house extensions and basements.

• Tip: Emphasise design that respects the terrace rhythm, scale, and materials. Context drawings and daylight/sunlight assessments often make the difference.

Richmond upon Thames

• Key issue: Strong conservation and design standards.

• Guidance: The House Extensions and External Alterations SPD is widely used.

• Tip: Respect garden space, limit bulk, and use high-quality matching materials. Engage with conservation officers early if in a sensitive area.

Hackney

• Key issue: Daylight and privacy in dense terraces.

• Guidance: Hackney applies BRE daylight/sunlight standards strictly.

• Tip: Commission a daylight/sunlight report if your design is close to boundaries. Roof extensions can be contentious unless they align with neighbouring patterns.

Islington

• Key issue: Sensitive heritage areas and high design expectations.

• Guidance: Islington is known for strong conservation policies and neighbour amenity protections.

• Tip: Demonstrate how your extension complements the original architecture. Simple, sympathetic designs usually fare best.

Wandsworth & Lambeth

• Key issue: Bulk of rear extensions and parking.

• Guidance: Both councils emphasise retention of garden space and street character.

• Tip: Show how your proposal won’t dominate neighbours’ views or reduce off-street parking where it’s valued.

Common Reasons Extensions Are Refused

1. Excessive bulk or height — proposals that overwhelm neighbours.

2. Loss of light and privacy — failure to consider overlooking or daylight/sunlight impact.

3. Unsympathetic design in conservation areas — inappropriate cladding, windows, or roof forms.

4. Basement risks — inadequate structural or flood impact assessments.

5. Incomplete applications — missing drawings, site plans, or design statements.

How to Check Your Own Property

1. Identify your borough using your postcode.

2. Review PD rights on the Planning Portal.

3. Check for Article 4 Directions on your borough’s website.

4. Download local SPDs for house extensions, basements, or conservation areas.

5. Consider pre-application advice for anything non-standard.

6. Prepare supporting documents — scaled plans, elevations, design & access statement, and daylight/sunlight reports if needed.

Case Study: Camden Terrace Extension

A homeowner in Camden wanted a glazed rear extension and loft conversion.

• PD rights would normally apply, but the property was in a conservation area with an Article 4 Direction.

• A pre-app revealed concerns about bulk and materials.

• The design was revised: brick matched the terrace, the roof was lowered, and obscure glazing reduced privacy issues.

• The application was approved with minor conditions — showing the value of adapting early.

Homeowner Checklist

✅ Check if your home has Article 4 Directions or is in a conservation area.

✅ Measure your design against PD limits.

✅ Read your borough’s extension SPD or design guide.

✅ Speak to neighbours — objections carry weight.

✅ Consider pre-application advice.

✅ Prepare a complete application pack with all drawings and statements.

Frequently Asked Questions

Do I always need planning permission for a rear extension in London?

Not always — single-storey rear extensions often fall under PD, unless your borough has removed those rights or you exceed size limits.

What is an Article 4 Direction?

It’s a legal tool used by councils to remove PD rights in certain areas, usually to protect conservation character.

How long does a householder application take?

Most boroughs decide within 8 weeks, but delays are common if documents are missing or objections are raised.

Can I start work while waiting for approval?

No. Work started without approval risks enforcement action and costly retrospective applications.

Final Thoughts

Extending your London home means balancing ambition with planning policy. Borough rules vary widely — what’s acceptable in Wandsworth may be refused in Camden. By checking Article 4 Directions, reading local design guides, and seeking pre-app advice, you’ll maximise your chance of approval and avoid wasted time and cost.

At Draw & Plan, we specialise in guiding homeowners through this process — from feasibility drawings to planning applications and building regs approval. If you’re planning a London extension, get in touch with our team for expert advice.

Disclaimer: This article is for general informational purposes only and does not constitute legal or professional advice. Always consult relevant professionals and local authorities before undertaking any development or change of use.