Kitchen Extension London and Hertfordshire
Transform your kitchen with a beautifully designed extension by LCCL Construction. We design and build open-plan kitchen extensions across London and Hertfordshire — from architectural drawings to construction and finishing, all under one roof. LABC Award Winners 2024. Over 200 reviews rated 4.7 out of 5. Prices from £40,000 for full design and build.
LABC Awards
Winners 2024
200+ Reviews
4.7 / 5 Rating
NFB Members
LABC Partners
What Is a Kitchen Extension?
A kitchen extension is a ground floor extension specifically designed to enlarge or transform your kitchen into a spacious open-plan kitchen-diner or kitchen-living area. It is one of the most popular and valuable home improvements in London, creating the heart of the home — a generous multi-functional space for cooking, dining, entertaining and family life.
Kitchen extensions typically involve extending the rear of the property by 3 to 6 metres and opening up the ground floor layout to create a single flowing space. The most successful kitchen extensions incorporate large areas of glazing — bi-fold doors, sliding doors, skylights and roof lanterns — to connect indoor and outdoor living and flood the space with natural light.
LCCL Construction is an award-winning design and build company based in Finchley, London N3. We specialise in kitchen extensions across London and Hertfordshire, handling every stage from architectural design through to construction and finishing. With over 20 years of experience, 200+ reviews rated 4.7 out of 5, and LABC Awards Regional Winners 2024, we deliver kitchen extensions to the highest standard.
How Much Does a Kitchen Extension Cost in London?
Kitchen extension costs in London typically range from £40,000 to £100,000 depending on the size of the extension, the kitchen specification and the level of structural work required. Here is a breakdown of typical costs in 2026:
Small kitchen extension (3 metres): £40,000 to £55,000 including design and build (excluding kitchen units).
Medium kitchen extension (4 to 5 metres): £55,000 to £75,000 including design and build (excluding kitchen units).
Large kitchen extension (6 metres): £70,000 to £100,000 including design and build (excluding kitchen units).
These prices include architectural design, structural calculations, building regulations, construction, electrics, plumbing, plastering and decoration. Kitchen unit supply and installation, specialist flooring and landscaping are typically additional.
Properties in Barnet, Finchley, Hendon, Muswell Hill, Edgware and across Hertfordshire fall within the standard cost range. Properties in prime London areas such as Hampstead, Highgate and Kensington may be higher due to access constraints and premium specifications.
Get an instant quote at lcclconstruction.co.uk or call 020 8037 7332.
Kitchen Extension Design Ideas
The best kitchen extensions are designed around how you live. Our architectural team works closely with every client to create a layout that balances cooking, dining, entertaining and everyday family use. Popular design features include:
Open-plan layouts that remove walls between the kitchen, dining room and living area to create one generous flowing space.
Bi-fold or sliding doors spanning the full width of the rear elevation, opening onto the garden and creating seamless indoor-outdoor living.
Roof lanterns and skylights positioned above the kitchen island or dining table to bring natural light deep into the space.
Kitchen islands with integrated seating, storage and appliances — the focal point of the modern kitchen extension.
Utility rooms and pantry storage designed into the layout so the main kitchen stays clean and uncluttered.
Underfloor heating throughout for consistent comfort.
Continuous flooring — engineered wood, porcelain tiles or polished concrete — running from the existing house through the extension to visually expand the space.
We design kitchen extensions for every property type — Victorian terraced houses, Edwardian semis, 1930s suburban homes and modern builds across London and Hertfordshire.
Planning Permission for Kitchen Extensions
Most kitchen extensions in London fall under permitted development rights and do not require planning permission. The same rules apply as for rear extensions — up to 3 metres on terraced and semi-detached houses, 4 metres on detached houses, or up to 6 to 8 metres under the larger home extension scheme with prior approval.
Planning permission is required for properties in conservation areas, listed buildings, and extensions exceeding permitted development limits. Side return kitchen extensions may also require planning permission depending on their proximity to the boundary and the local planning authority.
Building regulations approval is always required for kitchen extensions. This covers structural integrity, fire safety, insulation, drainage, electrics and ventilation. LCCL Construction handles all planning and building regulations applications as part of our service.
What Is Included in Our Kitchen Extension Service?
Our full design and build kitchen extension service includes:
Free consultation and project assessment.
Measured building survey.
Architectural design drawings.
Planning permission or lawful development certificate.
Building regulations submission.
Structural engineer calculations.
Party wall agreements where required.
All construction — foundations, steelwork, brickwork, roofing, drainage.
First and second fix electrics and plumbing.
Plastering, decoration and finishing.
Building control sign-off.
Optional 10-year LABC warranty.
We can also coordinate with your chosen kitchen supplier or recommend trusted kitchen companies we work with regularly.
How Long Does a Kitchen Extension Take?
A kitchen extension typically takes 12 to 18 weeks to build. The full timeline from consultation to completion is usually 5 to 7 months:
Timelines may be longer for larger or more complex projects involving significant structural alterations.
Areas We Cover
LCCL Construction designs and builds kitchen extensions across London and Hertfordshire including Barnet, Finchley, Hendon, Muswell Hill, Highgate, Hampstead, Southgate, Enfield, Edgware, Borehamwood, St Albans, Potters Bar, Bushey, Watford, Ealing, Clapham, Putney, Wandsworth, Hackney, Islington, Camden, Kensington and surrounding areas. Call 020 8037 7332 or visit lcclconstruction.co.uk to book a free consultation.
Frequently Asked Questions
Should I choose a kitchen extension or a loft conversion?
It depends on what you need. A kitchen extension adds ground floor living and dining space, while a loft conversion adds bedrooms and bathrooms. Many clients choose to do both — LCCL Construction specialises in combined extension and loft conversion projects.
Can I keep my existing kitchen while the extension is being built?
Yes, for most of the build. The connection between the existing house and the new extension is made towards the end of construction. We help clients plan temporary kitchen arrangements during the final stages.
Will a kitchen extension add value to my home?
A kitchen extension is one of the highest value-adding improvements you can make. Estate agents consistently report that open-plan kitchen-diners are the most sought-after feature for London buyers, typically adding 10% to 15% to property value.
Do you supply and fit kitchens?
We supply and fit the complete extension including all building work, electrics, plumbing and finishing. For the kitchen units and appliances, we can coordinate with your chosen supplier or recommend companies we work with.
How do I get started?
Call 020 8037 7332, book a free consultation at lcclconstruction.co.uk, or get an instant quote online.