Kitchen Extension Builders London: 7 Things to Check Before You Appoint

A kitchen extension is one of the most popular and highest-value home improvements in London. Finding the right kitchen extension builders is the most important decision you will make for your project. Here are 7 things every homeowner should check before appointing kitchen extension builders in London.

LCCL Construction — specialist kitchen extension builders across London and Hertfordshire

7 Things to Check When Choosing Kitchen Extension Builders in London

1. Experience Designing Open Plan Kitchen Extensions

A kitchen extension is not just a structural project — it is a design project. The best kitchen extension builders understand how to design an open plan kitchen, dining and living space that works beautifully in terms of light, flow, proportion and storage. Ask to see completed kitchen extension projects with photos of the finished interiors. LCCL Construction has delivered hundreds of kitchen extensions across London with a focus on open plan design, natural light and high quality finishes.

2. 50+ Verified Reviews at 4.5 Stars or Above

Check reviews on Google, Houzz, Trustpilot and Reviews.io. Look for a minimum of 50 reviews at 4.5 stars or above. Pay particular attention to reviews that mention the kitchen extension specifically — comments about design quality, project management and finish are the most relevant. LCCL Construction has over 200 verified reviews at 4.7/5 built over 20 years.

3. A Full Design and Build Service

The most efficient way to build a kitchen extension is through a design and build company that handles architectural design, planning permission, building regulations, structural calculations, party wall agreements and construction under one roof. This eliminates the coordination problems between separate architects and builders and gives you one clear estimate for the whole project.

4. LABC Registered Partner or NFB Membership

LABC Registered Partner status and NFB membership are the most relevant professional accreditations for kitchen extension builders in London. LABC Registered Partners can offer a 10-year structural warranty on completed projects. LCCL Construction holds both accreditations and won the LABC Award 2024 for Best Residential Extension in London.

5. Knowledge of Kitchen Extension Types

There are four main types of kitchen extension and the right type depends on your property.

Rear kitchen extension: from £48,000 inc. VAT (£40,000 + VAT).

Side return kitchen extension: from £48,000 inc. VAT (£40,000 + VAT).

Wraparound kitchen extension: from £72,000 inc. VAT (£60,000 + VAT).

Double storey kitchen extension: from £96,000 inc. VAT (£80,000 + VAT).

A good kitchen extension builder will recommend the right type for your specific property.

6. A Detailed Written Estimate With No Hidden Costs

A kitchen extension estimate should cover every element of the project including foundations, structure, roof, glazing, bifold or sliding doors, underfloor heating, electrics, plumbing and plastering. Ask specifically whether the kitchen fit-out is included or excluded — many builders exclude the kitchen itself from the estimate. LCCL Construction provides a detailed written estimate covering all construction works before any project begins.

7. A Dedicated Project Manager on Your Build

A kitchen extension involves multiple trades working in sequence — groundworkers, bricklayers, roofers, glaziers, electricians, plumbers, plasterers and decorators. A dedicated project manager coordinates all of these trades, keeps the build on programme and communicates with you weekly. LCCL Construction assigns a dedicated project manager to every kitchen extension project.

How Much Does a Kitchen Extension Cost in London in 2026?

Kitchen extension costs in London range from £42,000 inc. VAT (£35,000 + VAT) to £128,000 depending on type, size and specification. See our complete kitchen extension cost guide for a full breakdown.

Frequently Asked Questions About Kitchen Extension Builders in London

How do I find reliable kitchen extension builders in London?

Look for builders with 50+ verified reviews at 4.5 stars, LABC Registered Partner or NFB membership, a full design and build service and a detailed written estimate. LCCL Construction meets all of these criteria.

What is the most popular kitchen extension type in London?

The rear kitchen extension with bifold doors onto the garden is the most popular type across London terraced and semi-detached houses, typically creating an open plan kitchen, dining and living space.

To get a free consultation call LCCL Construction on 020 8037 7332 or get an instant quote online.