If you love your home but need more space, a well-planned extension can be life-changing. In London, where property prices are high and outdoor space limited, extending your existing home often makes far more sense than moving. Whether you’re adding a rear kitchen extension, a new bedroom, or a double-storey build, thoughtful design and smart budgeting can transform both the function and value of your property.
Types of Extensions: Rear, Side-Return & Double-Storey
Different homes suit different extension styles. Here are the most popular options London homeowners are choosing in 2026:
Rear Extensions
Perfect for terraced and semi-detached homes, a rear extension expands your ground floor into the garden. It’s ideal for creating open-plan kitchens, dining areas, or family rooms with direct garden access.
Advantages:
- Brings in natural light
- Creates open-concept living
- Seamless indoor-outdoor connection
Side-Return Extensions
Common in Victorian and Edwardian terraces, side-return extensions use the narrow alleyway along the side of the house to widen internal spaces without major external disruption.
Advantages:
- Adds width to kitchens or hallways
- Maintains garden size
- Typically faster and more affordable to build
Double-Storey Extensions
If you need significant additional living space, a double-storey extension adds both ground-floor and first-floor rooms; perfect for extra bedrooms, bathrooms, or offices.
Advantages:
- Doubles usable space
- Increases property value
- Allows for cohesive design across levels
At London Renovations, every extension is custom-designed to complement the property’s architecture while meeting modern living needs.
What Affects Extension Costs in London
Several factors influence the final price of a home extension. Understanding them upfront helps you budget more accurately:
| Factor | Description | Typical Impact |
| Design Complexity | Unique shapes, multiple levels, or structural adjustments | Increases labour and engineering costs |
| Materials & Finishes | Brick, glass, steel, or sustainable options | Affects both aesthetics and longevity |
| Access & Logistics | London properties often require careful site planning | Can affect delivery and labour time |
| Planning & Building Fees | Permissions, structural surveys, and compliance | Must be factored into overall cost |
For 2026, average London extension costs range from £2,500–£4,000 per square metre, depending on specification and finish.
How to Maximise Space & Light
Good design is about more than square footage, it’s about how that space feels.
Here’s how to create light-filled, functional extensions that enhance everyday living:
- Use Rooflights or Skylights: Bring sunlight deep into the interior.
- Opt for Open-Plan Layouts: Remove unnecessary partitions for flow and flexibility.
- Incorporate Glass Doors: Sliding or bi-fold doors visually expand your living space.
- Light-Reflective Finishes: Pale tones and reflective surfaces amplify natural brightness.
- Zoning: Define areas for cooking, dining, and relaxing through lighting and flooring changes.
London Renovations combines architectural design with energy-efficient glazing and spatial planning to ensure every metre counts.
Getting Planning Permission in London
Most home extensions require either Planning Permission or fall under Permitted Development Rights (PDR). Understanding which applies to your project is essential.
Planning Permission is typically required if:
- The extension exceeds set height or volume limits
- Your property is in a conservation area or listed
- You plan a double-storey addition or major façade change
Permitted Development may cover:
- Small single-storey rear extensions
- Certain loft and garage conversions
- Internal layout modifications
London Renovations handles all planning applications, structural calculations, and compliance with London Building Regulations, ensuring your project proceeds smoothly from approval to construction.
Final Checklist Before You Start
Before any work begins, confirm that you have:
- Architectural drawings and structural plans
- Planning and building regulation approvals
- Detailed, itemised quotation
- Timeline and payment schedule
- Site insurance and contracts in place
Proper preparation avoids delays, cost overruns, and compliance issues; setting your project up for success from day one.
Final Thoughts
A home extension is more than extra square footage, it’s an investment in comfort, lifestyle, and property value. By planning carefully, choosing trusted professionals, and prioritising design harmony, you’ll create a seamless addition that enhances your home for years to come.
Request a Free Extension Planning Consultation
Thinking about extending your home?
Contact London Renovations Ltd today for a free planning consultation. Our expert team will help you explore possibilities, assess feasibility, and design an extension tailored to your needs.
