Kitchen Extensions in London: Create Your Dream Open-Plan Kitchen

A kitchen extension is the most popular reason London homeowners choose to extend their property. Whether you dream of a large island kitchen, an open-plan kitchen-diner for family meals, or a kitchen-living space that opens onto the garden, a well-designed kitchen extension can transform the way you live. LCCL Construction designs and builds kitchen extensions across London and Hertfordshire, creating beautiful, functional spaces that add real value to homes.

Kitchen Extensions in London

Can it be done under permitted development?

A single-storey rear extension of 3 m on a terrace or semi (4 m on a detached house), a side-return infill and a side extension up to half the original width are permitted development on a house outside a conservation area or Article 4 street — no planning application, just a Lawful Development Certificate, which we apply for on every one. Fixed-price permitted development extensions start from £42,000 inc. VAT (£35,000 + VAT) at economy specification, design and build inclusive, and the 6 m / 8 m larger home extension goes through a 42-day prior approval notification rather than a full application. See our permitted development projects page for every product with its from-price and the checks we run before we confirm a project qualifies.

Not sure whether your project needs planning permission? Enter your postcode and tick what you want to build — we look up the conservation areas, Article 4 directions and listed buildings for you, and you see which parts are permitted development and the from-price for each. Lawful Development Certificate included on every permitted development job.

Planning check

Types of Kitchen Extension in London

There are several ways to extend your kitchen depending on your property type and layout. A rear extension is the most common approach, pushing the back wall out into the garden to create a larger kitchen or open-plan kitchen-diner. A side return extension fills in the narrow passage alongside terraced houses, adding width to a typically narrow kitchen. A wraparound extension combines both rear and side return for the maximum kitchen space. A double storey extension can create a large kitchen downstairs with a bedroom or bathroom above. Each approach has different costs, planning implications and design possibilities. LCCL Construction assesses your property and recommends the best option during a free consultation.

How Much Does a Kitchen Extension Cost in London?

The building work for a kitchen extension in London typically costs £42,000 – £153,600 inc. VAT (£35,000 – £128,000 + VAT) for a single storey extension in 2026. The kitchen itself is an additional cost on top: supplied and fitted by LCCL it runs £16,200 – £56,160 inc. VAT (£13,500 – £46,800 + VAT) for a mid-range kitchen and £25,200 – £87,360 inc. VAT (£21,000 – £72,800 + VAT) for high-end, depending on size; appliances, flooring and tiling are extra. A side return infill for a wider kitchen costs £42,000 – £93,600 inc. VAT (£35,000 – £78,000 + VAT) for the building work. A wraparound extension creating a large kitchen-diner costs £126,000 – £153,600 inc. VAT (£105,000 – £128,000 + VAT). These prices include all design, structural work, building regulations and construction. LCCL Construction provides detailed fixed-price quotes that break down every element so you know exactly what you are paying for.

Design Ideas for Kitchen Extensions

The most popular kitchen extension design in London is an open-plan kitchen-diner-living area with bi-fold or sliding doors opening onto the garden. A large kitchen island provides both workspace and informal dining. Vaulted or raised ceilings with rooflights create a sense of space and flood the room with natural light. Underfloor heating keeps the floor warm and eliminates radiators, freeing up wall space for cabinetry. Utility rooms and pantry storage can be incorporated into the extension design to keep the main kitchen uncluttered. Many clients also include a separate snug or family room within the open-plan layout using subtle level changes or furniture placement.

Planning and Building Regulations for Kitchen Extensions

Most single storey kitchen extensions in London fall under permitted development rights and do not require planning permission, provided they meet the size limits of 6 metres on terraced and semi-detached houses or 8 metres on detached houses. Building regulations approval is always required and covers structural integrity, insulation, ventilation, electrics and drainage. If your extension includes plumbing for a kitchen sink, dishwasher and washing machine, the drainage connections must meet building regulations standards. LCCL Construction handles all planning applications and building regulations as part of our design and build service.

Build Your Dream Kitchen with LCCL Construction

LCCL Construction delivers kitchen extensions across London and Hertfordshire with a complete design and build service. We handle architectural design, planning, building regulations, structural calculations, party wall agreements, all construction, electrics, plumbing and finishing. We work with your chosen kitchen supplier or can recommend trusted kitchen companies we have partnered with on previous projects. With over 20 years of experience, 200 plus reviews rated 4.7 out of 5, and the LABC Awards Regional Winner 2024, you can trust LCCL Construction with your kitchen extension. Call 020 8037 7332 or book at lcclconstruction.co.uk/booking-calendar/free-consultation-call.