Planning Permission Guide for Extensions & Loft Conversions in London & Surrey

Planning an extension or loft conversion in London or Surrey is an exciting way to elevate your living space and unlock your property’s true value. However, navigating planning permission and building regulations can seem overwhelming, especially with varying local authority rules and the ever-changing requirements in 2025. This guide will walk you through the essential steps, common pitfalls, and expert strategies—ensuring your home improvement journey is as smooth and successful as possible.

Why Planning Permission Matters

For most substantial home extensions and loft conversions, you will need formal planning permission from your local council. Without it, your project could face delays, enforcement action, or even the requirement to reverse unauthorized work. Some smaller projects fall under permitted development (PD) rights, meaning they don’t require full planning permission, but these rights have limits based on your property type, previous alterations, and location (such as Conservation Areas or for Listed Buildings).

If in doubt, apply for a Lawful Development Certificate—a formal confirmation from the council that your project doesn’t need full planning permission. NFA Architecture offers guidance on the best route based on your plans and property type.

Step-by-Step: Securing Planning Permission

1. Preparing Your Application

Success starts with detailed architectural drawings, precise measurements, and a thorough understanding of both your vision and local policy. NFA Architecture specialises in preparing professional drawings and comprehensive planning applications, tailored to meet council requirements and intended to speed up approvals.

• Collate necessary documents, including site plans, elevations, and supporting statements.

• Ensure compliance with local authority design guidelines.

• Use accurate digital scans (a service provided by NFA) to minimise errors and back-and-forth with inspectors.

Explore our architectural design services for expertly prepared planning documents.

2. Checking Local Policies and Constraints

Regulations can change depending on where you live. Conservation areas, Article 4 Directions, flood zones, and previous extensions can all restrict PD rights and require bespoke solutions.

• Use your local council’s planning portal to check property history, constraints, and map overlays.

• Consult planning officers or an expert architectural company for clarity on local nuances.

Discover the areas we cover in London and Surrey and the specific expertise NFA brings to each.

3. Submitting the Application

As of 2025, all planning applications in England are submitted online through the Planning Portal. This includes householder applications for extensions, loft conversions, and Lawful Development Certificates.

• Submit your plans, forms, and supporting information digitally.

• Pay the requisite planning fee (fees updated nationally in April 2025).

• Maintain open communication with your architectural consultant for tracking and responding to any requests for further information.

Visit our planning permission resources for step-by-step support—and see how NFA’s end-to-end service simplifies your application.

4. Dealing With Building Regulations

Planning permission and building regulations approval are distinct but often required together. Building regulations focus on safety, energy efficiency, and structural integrity, and you’ll need technical drawings to secure approval.

• NFA Architecture provides in-house structural engineering and compliant building regulations drawings.

• These are essential for your builder and for passing council inspections.

Key Considerations for 2025

• Processing Times: For single-family additions and renovations in Surrey, current permit processing times average 3.4 weeks, provided all documents are complete—an improvement on previous years.

• Changes to Local Development Plans: Surrey councils have ongoing reviews of housing targets and policies, particularly affecting extensions in green belt areas5. Stay up to date on local consultations.

• Party Wall and Highways Issues: Some projects impact shared walls or public pathways. NFA assists with party wall agreements and guidance on vehicle crossovers through Surrey County Council, ensuring your project doesn’t stall at the last hurdle.

Avoiding Common Mistakes

• Starting work before permission is secured—a costly misstep.

• Submitting incomplete or inaccurate plans, leading to delays and rejections.

• Ignoring site constraints or not engaging with neighbours on party wall matters.

Why Use NFA Architecture?

• Expert Local Knowledge: Decades’ experience securing planning approvals across London and Surrey, including challenging permissions in Conservation Areas and for Listed Buildings.

• Comprehensive Service: From digital surveys and concept design to planning, building regulations, and contract administration.

• High Approval Rates: Demonstrated by client testimonials and recent successes in 2025.

Meet our team and read how we deliver stress-free results with a personalised approach.

Frequently Asked Questions (FAQs)

• Do I always need planning permission for an extension or loft conversion?
  Not always—some are covered by PD rights, but many homes have restrictions or require formal applications, especially in London and specified areas of Surrey.

• How long will approval take in 2025?
  For typical single-family extensions in Surrey, the average is 3.4 weeks if documentation is complete, but complex cases may take longer. Allow for extra time for pre-application consultation or revisions.

• Can I apply online?
  Yes, use the national Planning Portal for all applications, whether for planning permission, building regulations, or certificates of lawfulness.

Ready to Start Your Project?

Securing planning permission is essential for a successful loft conversion or home extension. With NFA Architecture, you benefit from experienced professionals, local authority insight, and end-to-end guidance—transforming your vision into reality with minimal hassle.

Contact us today for a free quote and expert consultation. Let’s make your dream home a reality—stress-free and fully compliant, right from the start.

Explore our recent projects in London and Surrey, and learn why homeowners trust NFA for all their architectural needs.