Planning Permission Guide for Extensions & Loft Conversions

Planning a home extension or loft conversion in London and the surrounding areas can be one of the most transformative choices for your property—adding space, value, and enjoyment. Yet, navigating planning permission can be complex, with shifting rules and local council requirements that every homeowner must consider in 2025. At CAB Design & Build, we help clients across Worcester Park, Surrey, and greater London secure the approvals they need, from kitchen extensions to full loft conversions. This guide breaks down planning permission essentials, popular keywords, and internal tips to help you move forward with clarity and confidence.

Understanding Planning Permission: The Basics

Planning permission is the consent required from your local council for most major building works, such as extensions or converting your loft into a habitable space. Not all projects need full permission; some fall within “permitted development rights,” which allow you to undertake certain works without submitting a full planning application.

Permitted Development:
For many loft conversions and small extensions, you may not need planning permission if the proposed works are within specific height, volume, and placement limits. For example, side extensions in London must typically be single storey, and rear extensions or loft conversions cannot exceed a set volume (40m³ for terraced houses, 50m³ for others). However, flats, maisonettes, listed buildings, conservation areas, or past property alterations may limit your options.

Planning Permission Required:
You’ll need formal permission if your project:

• Is on designated land (conservation area, listed, or Article 4 direction area)

• Exceeds the size or height limits for permitted development

• Involves significant structural change or changes to building use

• Adds features like balconies or raised terraces.

Tip: Even if your project qualifies for permitted development, getting a “certificate of lawfulness” is wise—it’s valuable for resale and prevents future disputes.

Step-by-Step Planning Permission Process

1. Free Consultation & Feasibility Survey

At CAB Design & Build, we begin each project with a complimentary consultation and onsite survey in Worcester Park, Surrey, and the surrounding London areas. We assess your goals, check property history, and advise if your extension or loft conversion is likely to require permission or fits within permitted development rights.

2. Concept Design & Planning Drawings

Our design team develops detailed architectural drawings and 3D visuals tailored to your needs. We ensure designs reflect local council policies and align with current guidelines for planning approval. Getting your plans right at this stage can dramatically speed up the process.

3. Application Preparation & Submission

We compile all required documents, including:

• Location and site plans

• Detailed drawings

• Design & access statements

• Application forms

CAB Design & Build submits your application digitally to your local authority—handling all correspondence, tracking progress, and responding promptly to council queries.

4. Neighbour Consultations & Council Review

For planning applications, local councils invite comments from neighbours—especially relevant in busy areas like Worcester Park or South West London. CAB supports you in handling objections and can adapt designs if required.

5. Approval, Conditions, and Next Steps

Most planning applications are decided within 8–12 weeks in London and Surrey. If approved, you receive written consent (sometimes with conditions). If refused, we help with re-design, re-submission, or appeals when necessary.

Key Tips for Success in London & Surrey

• Understand Local Variations: Permitted development rights and local planning interpretations can vary—CAB’s knowledge of borough policies in Worcester Park, Surrey, and surrounding areas avoids costly mistakes.

• Building Regulations Still Apply: Separate from planning permission, these govern safety, structure, and insulation—we handle both seamlessly.

• Party Wall Agreements: In semi-detached or terraced houses, you may need an agreement with neighbours before work begins.

• Secure a Certificate of Lawfulness: Essential if selling your property in future.

Common Questions

Q: How long does planning approval take?
A: Typical applications in London or Surrey take 8–12 weeks, but complex projects or busy periods can mean longer.

Q: Can I start work before permission is granted?
A: No—beginning without written permission risks enforcement action.

Q: What if my application is refused?
A: CAB Design & Build will help revise your plans or manage an appeal.

Why Choose CAB Design & Build?

• Local expertise: Over a decade of experience winning planning approvals in Surrey, Worcester Park, and greater London.

• Complete service: From free consultation to final sign-off, you have a single, trusted team.

• Transparent pricing: Fixed quotes, no hidden fees, and full deposit protection.

• End-to-end support: Dedicated project manager ensuring every detail is overseen—on time, and within budget.

Ready to Begin Your Home Extension or Loft Conversion Project?

Don’t let planning permission challenges delay your dream home upgrade. With local knowledge, full project management, and hundreds of satisfied clients, CAB Design & Build makes extending or converting your space in London or Surrey easy.

Book your free, no-obligation consultation today—visit ConsultABuilder.co.uk, call us, or use our contact form to get started.
Transform your home with expert help, and experience the peace of mind that comes with a trusted partner by your side.