Kitchen Extension Cost London 2026: Complete Price Guide by Size and Type

A kitchen extension is one of the most popular home improvements in London — it creates a large, light-filled open plan kitchen, dining and living space that dramatically improves how you use your home and delivers exceptional value uplift. Kitchen extensions can be built as rear extensions, side returns, wraparound extensions or double storey extensions depending on your property. This guide gives you accurate 2026 kitchen extension costs across all four types so you can budget realistically before starting your project. LCCL Construction has delivered hundreds of kitchen extensions across London and Hertfordshire.

LCCL Construction — specialist kitchen extension builders across London

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

Kitchen extensions in London cost between £35,000 and £128,000 in 2026 depending on the type and size of extension. The average project cost is £55,000 to £85,000 for a typical Victorian or Edwardian terrace kitchen extension. This includes architectural design, planning permission where required, building regulations, structural calculations, party wall notices and all construction works. Kitchen units, appliances and worktops are typically supplied by the client on second fix.

Kitchen Extension Cost by Type in London

Rear kitchen extension: £35,000 to £75,000. Extends the kitchen straight out into the garden — the classic approach. See our full rear extension cost guide.

Side return kitchen extension: £35,000 to £78,000. Fills the narrow side alley alongside a Victorian or Edwardian terrace kitchen. See our full side return cost guide.

Wraparound kitchen extension: £60,000 to £128,000. Combines rear and side return for the largest open plan kitchen space possible. See our full wraparound cost guide.

Double storey kitchen extension: £75,000 to £165,000. Adds kitchen space downstairs plus bedrooms or study upstairs. See our full double storey cost guide.

What Affects Kitchen Extension Cost in London?

The main factors are: size in square metres, type of extension, structural complexity of removing existing kitchen walls, specification of glazing including bifold doors sliding doors and roof lanterns, quality of internal finishes, planning permission requirements and location within London. Central London postcodes cost 15-25 per cent more than outer London.

What Is Included in a Kitchen Extension Cost?

LCCL Construction kitchen extension costs include: measured building survey, architectural design, planning permission application, building regulations, structural engineer calculations, party wall notices, groundworks and foundations, steelwork to remove existing kitchen walls, superstructure, roof, external brickwork or render, bifolds or sliding doors, first fix electrics and plumbing including new kitchen supply and waste points, insulation, plastering, second fix and decoration. Kitchen units, appliances, worktops and splashbacks are typically supplied and installed by the client's kitchen supplier on second fix.

Should I Include the Kitchen Units in My Budget?

Yes — a full kitchen fit-out including units, appliances, worktops, tiling and lighting typically adds £15,000 to £75,000 on top of the extension construction cost. A standard kitchen fit-out is £20,000 to £35,000. A premium kitchen with quartz worktops, integrated appliances and bespoke cabinetry can reach £50,000 to £100,000+. This is normally supplied direct by kitchen companies rather than the construction contractor.

How Much Value Does a Kitchen Extension Add?

A well-designed kitchen extension in London typically adds 175 to 300 per cent of the construction cost in property value. A £65,000 kitchen extension typically adds £115,000 to £195,000 in outer London and £180,000 to £320,000+ in premium locations. Kitchen extensions deliver exceptional returns because the kitchen is the highest-value room in the modern home. See our full guide on how much value an extension adds.

Frequently Asked Questions About Kitchen Extension Cost in London

How much does a kitchen extension cost in London?

From £35,000 for a small rear or side return to £128,000 for a large wraparound with premium specification.

How long does a kitchen extension take?

Typically 12 to 16 weeks on site for a single storey, 18 to 24 weeks for a double storey. Design and planning add another 12 to 16 weeks upfront.

Does the extension builder install the kitchen?

Usually no. The construction contractor delivers the extension structure and first fix. Kitchen units and appliances are typically supplied and installed by specialist kitchen companies on second fix.

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