Adding a kitchen extension is one of the most effective ways to transform the heart of your home. Not only does it create more space for cooking, dining, and entertaining, but it can also boost the value of your property. At MBT Group, we’ve helped countless London homeowners design and build kitchen extensions that blend practicality with style.

In this guide, we’ll explore kitchen extension costs in 2025, planning considerations, timelines, design inspiration, and useful tips to help you get the most from your project.

How Much Does a Kitchen Extension Cost in London?

When planning a kitchen extension, the cost is usually the first factor homeowners want to understand. While every project is unique, here are some average price guidelines for London kitchen extensions:

• Standard Single Storey Extension: Around £1,500 per m² for a straightforward build.

• Bespoke Extension: Featuring custom windows, doors, or high-end finishes – between £1,900 to £2,200 per m².

• High Specification Extension: Premium materials, architectural features, and luxury finishes – up to £3,000 per m².

• Internal Redesign Work: Adjusting the layout inside your existing home – around £500 to £900 per m².

These figures are estimates, and your final budget will depend on the complexity of the design, materials chosen, and any structural changes required. It’s also important to allow a contingency fund of 10–15% for unforeseen costs.

If you want to compare different extension types, you may also find our blog useful:
👉 Guide to Single Storey Extension Costs in London

Planning Permission and Building Regulations

Before starting your kitchen extension, you’ll need to know whether planning permission is required. The rules vary depending on your property type, size of the extension, and location.

Under Permitted Development, you can usually build:

• Single-Storey Extensions: Up to 6m from the original rear wall of an attached house or 8m for a detached house. The height must not exceed 4m, or 3m if within 2m of the boundary.

• Double-Storey Extensions: Must be at the rear, not extend more than 3m beyond the rear wall, and must not exceed the existing roof height.

However, if your property is in a conservation area or is a listed building, different restrictions apply. For full guidance, visit planningportal.co.uk or consult with our expert team at MBT Group.

Key Considerations Before You Build

✅ Do: Get Detailed Plans

Work with professional builders and designers to create a precise plan. This should include cost estimates, materials, timelines, and a clear outline of who is responsible for each part of the build.

✅ Do: Plan for Material Storage

Large-scale projects require space to store building materials. Ensure you have a secure, accessible area to keep everything safe and organised.

❌ Don’t: Micromanage

Once you’ve agreed on a plan and price with your builder, trust them to get the job done. Each trade professional has their own method, and excessive interference can slow progress.

❌ Don’t: Be Unclear on Responsibilities

If you’re taking on part of the project yourself – for example, painting or flooring – clarify this from the start to avoid confusion.

Kitchen Extension Timeline

While every project differs, here’s a general week-by-week breakdown for a single storey kitchen extension in London:

• Week 1: Site preparation

• Week 2: Groundwork and foundations

• Weeks 3–4: Wall construction and structural work

• Weeks 5–6: Internal and external wall completion

• Week 7: Roof structure installation

• Week 8: Roof covering

• Weeks 9–10: Guttering, windows, and doors fitted

• Weeks 11–12: Knock-through, plastering, and insulation

• Week 13: Flooring and finishing touches

• Week 14: Snagging and landscaping

Depending on complexity, weather conditions, and material lead times, this schedule may vary.

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Kitchen Extension Design Ideas

Your kitchen extension should reflect both your lifestyle and your home’s architectural style. Here are some popular ideas:

1. Open-Plan Kitchen and Dining Area – Perfect for entertaining and family gatherings.

2. Glass Roof or Skylights – Bring in natural light and make the space feel bigger.

3. Side Return Extension in London – Utilise unused space along the side of your property to extend your kitchen without sacrificing garden space.

4. Kitchen Island Centrepiece – Adds storage, prep space, and a social hub.

5. Indoor-Outdoor Flow – Bi-fold doors leading to a patio create a seamless transition to your garden.

For more creative inspiration on home renovations, you might also like:
👉 Stylish Loft Conversion Ideas for London Homes in 2025
👉 Is It Expensive to Build a Basement in the UK?

• Why Choose MBT Group for Your Kitchen Extension in London?

  At MBT Group, we pride ourselves on delivering beautiful, functional, and durable extensions tailored to your needs. From side return extensions in London to large-scale bespoke kitchen builds, we manage every step – design, planning, construction, and finishing.

  Our experience means we can advise on cost-effective solutions without compromising on quality, ensuring your extension adds lasting value to your home.

  If you’re also exploring other home improvements, see:
  👉 What Makes a Great Property Maintenance Team in London?
  👉 How to Build a Shed That Lasts – A Step-by-Step Guide

 

Those in search of a rear kitchen extension will love this design, which mixes modern and contemporary themes.

This sleek, modern design gives plenty of space with monochrome stylings.

The gold of the lamps and the leather bar stools accentuate the clean design of this kitchen.

Those looking for small kitchen extension ideas can take inspiration from this design.

If you’re looking for a kitchen extension with skylights, they don’t come much better than this one.

When it comes to conservatory kitchen extensions, this modern take is absolutely stunning.

Start Planning Your Kitchen Extension Today

A well-designed kitchen extension is more than just extra space – it’s an investment in your lifestyle and property value. Whether you’re dreaming of a sleek modern kitchen or a cosy family space, MBT Group can bring your vision to life.

Contact MBT Group today to discuss your kitchen extension project in London. Let’s create a kitchen you’ll love for years to come.