What is the best type of kitchen extension?

It depends on what your kitchen lacks. If it is a narrow galley in a terrace with a side alley, a side return kitchen extension adds the width that transforms it. If the room is a decent width but short on space, a rear kitchen extension pushes into the garden and adds depth, often without planning permission. If you want the full open-plan kitchen-dining-living transformation, a wrap-around combines both. We look at your house at a free survey and recommend the route honestly, including what each would cost.

How much does a kitchen extension cost in London in 2026?

In London in 2026 the extension itself typically costs 48,000 to 120,000 pounds including VAT depending on the route: a compact 3-metre rear kitchen extension around 48,000 to 65,000 pounds, a side return kitchen extension 60,000 to 85,000 pounds, a 4 to 5 metre rear kitchen-diner 65,000 to 95,000 pounds, and a wrap-around kitchen 95,000 to 120,000 pounds. The kitchen fit-out itself, meaning units, worktops and appliances, is budgeted separately: as a broad guide 10,000 to 30,000 pounds for a quality mid-range kitchen and 40,000 pounds or more for high-end schemes. We fix the build price in writing after a free survey, and every figure includes VAT.

How much should I budget for the kitchen itself?

Industry cost guides put a full UK kitchen installation at roughly 5,000 pounds for a small budget kitchen, around 10,000 pounds for a good mid-range one, and 28,000 pounds or more for a large high-end kitchen, while London architect-led projects commonly spend 15,000 to 60,000 pounds. For most West London kitchen extensions a realistic fit-out budget is 10,000 to 30,000 pounds. The kitchen is priced separately from the build so you control the spec, and we are happy to fit the kitchen you choose or work alongside your supplier's fitters.

Do you need planning permission for a kitchen extension?

It depends on the route. A rear kitchen extension of up to 3 metres on a terraced or semi-detached house, or 4 metres on a detached house, is usually permitted development with no planning application needed, and up to 6 or 8 metres is possible with prior approval. A side return kitchen extension often needs planning, and always does in a conservation area. A wrap-around always needs a full application. We confirm your exact route at the free survey and prepare whichever application or certificate your project needs.

How long does a kitchen extension take?

Most single-storey kitchen extensions take around 10 to 16 weeks on site, and a wrap-around 14 to 20 weeks. Before work starts there is a design and approvals stage covering drawings, any planning application and party wall notices, so allow a few months from first survey to breaking ground. We give you a realistic programme with the fixed-price contract, including when the old kitchen comes out and the new one goes in.

Can I still use my kitchen during the build?

For much of the build, yes. The new extension is built and made weathertight outside the existing wall first, so your kitchen usually keeps working through the early months. There is then a period, typically a few weeks, when the wall is opened, services move and the new kitchen is fitted, when you will need a temporary set-up. We plan that stage with you in advance, keep it as short as possible, and set up a temporary kitchen area so you are never without the basics.

Is an orangery or conservatory kitchen extension a good idea?

For a kitchen you use every day, a solid-roofed extension with generous glazing usually beats both. A conservatory is largely glass, so it swings too hot and too cold for reliable daily cooking, and building regulations treat an open-plan glazed structure strictly. An orangery-style extension, meaning solid walls and a substantial roof lantern, gives you most of the light with far better insulation, and we build that as a standard extension with a lantern. You get the bright, garden-facing feel without the greenhouse drawbacks.

West London & Surrey Extension Specialists

Kitchen
Extension London

A kitchen extension turns the most-used room in the house into the best one: a large, open-plan kitchen-diner with light pouring in and doors opening onto the garden. Whether that means a side return, a rear extension or a full wrap-around, we are the kitchen extension builders West London homeowners call when they want the whole project handled: design, planning, party wall, structural steel, glazing, building control and the kitchen fitting itself, under one fixed-price contract with every price including VAT.

📋 Book Free Survey 📞 +44 7404 931629

2010Building Since

10–16Weeks On Site

5.0★Google · Checkatrade

Inc VATFixed-Price

📐

Design & Build In-House

Drawings, planning, steel, glazing and kitchen fit under one roof

💷

Fixed Price Inc VAT

The survey number is what you pay, with no surprise 20%

🧱

Party Wall Handled

We manage the whole neighbour & party wall process for you

✅

Building Regs Sign-Off

Full compliance and completion certificate included

Why A Kitchen Extension?

Build the room your family actually lives in

Most West London kitchens were designed a century ago for a very different life: small, closed off, and facing away from the garden. A kitchen extension fixes that at the root, creating an open-plan kitchen diner extension with space to cook, eat and gather in one bright room.

There are three ways to get there, and we build all of them. A side return kitchen extension adds width to a narrow terrace kitchen. A rear kitchen extension adds depth into the garden, often with no planning application needed. And a wrap-around combines both for the full open-plan transformation. The right route depends on your house, and we will tell you honestly which one fits at a free survey.

Unlike most kitchen extension companies, we take the project all the way: design, planning, structure, glazing and the kitchen fitting itself, with all trades in-house, one fixed price including VAT, and a 2-year workmanship guarantee. See also our extension cost guide and planning guide.

★★★★★

We went from a kitchen you couldn't fit two people in to an island, a dining table and bifolds onto the garden. One team did everything, including fitting the kitchen…

Verified client · West London

Google & Checkatrade reviewed

Finished kitchen extension in London: an open-plan kitchen-diner with island, roof lantern skylights and bifold doors opening onto the garden — Completed Kitchen ExtensionOpen-plan kitchen-diner with island, lantern and bifolds, West London

Shell + Kitchen, Planned Together

The Extension Is Only Half The Project

A kitchen extension is really two projects in one: the structure, and the kitchen inside it. Most problems on these jobs come from planning them separately. We design both together from day one.

2-in-1 Structure and kitchen
designed as one project,
not bolted together

1Services go in before steel goes up. Drainage, gas, extraction and electrics are decided by where the sink, hob and island will sit. Fixing the kitchen layout at the drawing stage means every pipe and cable is put in the right place first time.
2The layout drives the design. The working triangle of sink, hob and fridge, an island with a metre of clearance each side, a U-shape kitchen for narrower rooms: we plan the zones for cooking, eating and sitting, then shape the extension around them.
3Light where you work. Skylights or a roof lantern over the worktops, bifold doors where the table meets the garden. Glazing placed around the layout, not the other way round.

Worried about living without a kitchen during the build? You mostly won't have to. The extension is built and made weathertight outside your existing wall first, so your kitchen keeps working through the early months. The changeover period is planned with you in advance and kept as short as possible. Book a free survey and we will walk you through the programme.

Three Routes To A Bigger Kitchen

Side Return, Rear Or Wrap-Around?

Every kitchen extension takes one of three routes, and each has its own dedicated page: side return, rear extension and wrap-around. Here is the short version, compared honestly.

Factor	Rear Kitchen Extension	Side Return Kitchen Extension
What it adds	Depth into the garden across the full width	Width across the dead side alley
Best for	Kitchens that are wide enough but too small	Narrow galley kitchens in Victorian terraces
Planning	Often permitted development (3m/4m, or 6m/8m with prior approval)	Often needs planning, always in conservation areas
Cost guide	£48,000–£95,000 inc VAT	£60,000–£85,000 inc VAT
Signature move	Bifolds across the back, island facing the garden	Roof lantern over the old alley, full-width worktops

Want both width and depth? That is the wrap-around kitchen extension: £95,000–£120,000 inc VAT and the biggest transformation of the three. We recommend the right route for your house at the free survey.

Ways To Build It

Kitchen Extension Ideas

Every kitchen extension is shaped by your house and how you cook and gather, but most projects fall into one of these. Not sure which suits yours? Book a free survey and we will design around your home.

Open-Plan Kitchen-Diner

The classic: a rear or side return extension opening the kitchen into one bright room with an island, a dining table and doors to the garden. Zoned for cooking, eating and sitting so it works as hard at 7am as it does at dinner.

Orangery-Style Kitchen Extension

Solid walls with a substantial roof lantern: most of the light of a glazed orangery with far better insulation than a conservatory kitchen extension. Built as a proper extension to building regulations, so it works every day of the year.

Best for lightLantern +£6k–£15k

Why not a conservatory? Too hot in July, too cold in January.

Small Kitchen Extension

Two to three metres of extra depth or width transforms a cramped kitchen: room for a table, a run of worktop, or a compact island. Often permitted development, simpler structure, and outstanding value per square metre of change. Ideal for semi-detached homes.

Best value£48k–£65k + kitchen

Best for: semis and smaller terraces on a focused budget.

Wrap-Around Kitchen

The full transformation: side return and rear combined into one L-shaped kitchen-dining-living space, with a lantern over the side and bifolds across the back. The premium option, covered in depth on our wrap-around page.

Maximum space£95k–£120k + kitchen

Note: always needs full planning permission.

Match Your Home

The Right Kitchen Extension For Your House

Use this as a starting point. Every house, boundary and budget is different, so we confirm the best design and the planning route on the free survey.

Your Home	Best Option	Why
Victorian terrace, narrow galley kitchen	Side return kitchen extension	The dead alley becomes the width the kitchen always lacked.
Kitchen wide enough, just too small	Rear kitchen extension	3m of depth, often with no planning application needed.
Want kitchen, dining and living in one	Wrap-around kitchen	Width and depth together for the full open-plan space.
Semi-detached, modest budget	Small kitchen extension	2–3m of extra space transforms the room at the lowest cost.
Dark kitchen, wants maximum light	Orangery-style with lantern	Solid roof with a big lantern beats a conservatory for daily use.
Conservation area home	Rear or side (with planning)	Still very doable; the design is tuned for approval and we handle the application.

Transparent Pricing

Kitchen Extension Cost, London 2026

A kitchen extension has two budgets: the extension itself, and the kitchen that goes in it. Most quotes blur them together; we keep them separate so you control the spec. The build ranges below are for London in 2026 and include the structural shell, roof, standard glazing, plastering and building control. Every build price includes VAT. For the full picture see our house extension cost guide.

Project	Typical London Cost	Build Time	Planning
Small kitchen extension (2–3m rear)	£48,000 – £65,000	10–12 weeks	Usually PD
Side return kitchen extension	£60,000 – £85,000	12–14 weeks	Often needed
Rear kitchen-diner (4–5m)	£65,000 – £95,000	12–16 weeks	PD / prior approval
Wrap-around kitchen	£95,000 – £120,000	16–20 weeks	Full planning
Kitchen fit-out (units, worktops, appliances)	£10,000 – £30,000+	2–3 weeks	Your choice of spec
Roof lantern & bifold upgrade	+ £6,000 – £15,000	Within build	Included in build

Build ranges are indicative for London 2026, including VAT, structural steel and building control, at roughly £2,800–£5,500 per m². Kitchen fit-out is a broad guide: UK industry figures put a full installation at around £5,000 for budget, £10,500 mid-range and £28,000+ for large high-end kitchens (see Checkatrade), while London architect-led projects often spend more. Try our free cost calculator for a tailored estimate.

Where you can keep the cost down. The kitchen itself is the biggest lever: a well-chosen mid-range kitchen in a beautifully built extension looks and works better than a premium kitchen squeezed into a compromised space. After that, a standard rooflight instead of a structural lantern, standard doors instead of full-width bifolds, and keeping the sink and drainage near their existing runs each save real money. We show you exactly where the money goes at the survey, so you choose the trade-offs rather than discovering them later.

Planning & Permitted Development

Do You Need Planning Permission?

It depends on the route, and often the answer is no. We confirm your exact position at the survey and prepare whichever application or certificate your project needs. Full guidance is on the Planning Portal, and we cover it in our extension planning guide.

✅ Often No Application Needed

✓ A rear kitchen extension up to 3m (4m detached) is usually permitted development
✓ Up to 6m/8m is possible via the prior-approval route, with neighbours consulted first
✓ Max height 4m, eaves ≤3m within 2m of a boundary, matching materials
✓ Where the work is PD, we recommend a Lawful Development Certificate (£274) so you hold council paperwork proving it

📋 Planning Permission Needed

→ Most side return kitchen extensions, and all of them in conservation areas
→ Every wrap-around kitchen extension
→ Schemes beyond the PD depth bands, flats and listed buildings
→ Householder application fee £548, decision typically in around 8 weeks, prepared and managed by us

The party wall bit everyone worries about. On a terrace or semi the build or the dig almost always involves the boundary, so the Party Wall etc. Act 1996 applies and notices must be served. It is routine, and we manage the whole process for you. These notes are a general guide (current as of July 2026, per the Planning Portal), not formal planning advice for your property: the free survey confirms your lawful route in writing before anything is built.

What's Included

One Fixed Price, Everything Handled

A kitchen extension touches groundworks, drainage, structure, roofing, glazing, services and fit-out, so a clear scope matters. Here is what our fixed price includes as standard, and what to budget separately.

✓ Included As Standard

✓ Free survey, feasibility, measured drawings & kitchen layout design
✓ Structural engineer's calculations & steel beams
✓ Planning application, prior-approval notification or LDC
✓ Party wall notices & process management
✓ Foundations, groundworks & drainage diversions
✓ Structural opening into the existing house
✓ Roof with rooflights, weathertight
✓ Insulation to Part L, plastering & first-fix plumbing and electrics
✓ Gas, water and electrical certificates on completion
✓ Building control sign-off & completion certificate
✓ Scaffolding, skip hire & site management

+ Budget Separately For

+ Kitchen units, worktops & appliances (your spec, typically £10k–£30k)
+ Kitchen fitting: we fit the kitchen you choose, or work with your supplier's fitters
+ Bifold or sliding doors (upgrade from standard glazing)
+ Roof lantern (upgrade from standard rooflights)
+ Flooring: tile, engineered wood or polished concrete
+ Underfloor heating (popular in kitchen-diners)
+ Decoration, lighting design & landscaping
+ £548 planning fee or £274 LDC (third-party council cost)

All build prices include VAT. Keeping the kitchen budget separate means you control the spec, and nothing is hidden inside a single blurry number.

How It Works

Our Five-Step Process

From first survey to cooking in the finished room, a clear process keeps a kitchen extension on time and on budget, with no surprises in scope, timing or cost.

Free Survey & Feasibility

Our project manager measures the kitchen, side return and rear, checks drains and boundaries, and talks through the route, the kitchen layout and a realistic budget. Around 45 minutes, no obligation.

Design, Kitchen Layout & Approvals

Drawings, engineering and the kitchen layout are designed together, so services land in the right place. We submit the planning application or LDC and serve party wall notices, all managed for you.

Fixed-Price Contract

You get a written contract, inclusive of VAT, covering every element of the build. The agreed price does not change unless you request a change.

Build, Changeover & Fit-Out

The extension goes up and is made weathertight while your old kitchen keeps working. Then the planned changeover: wall opened, services moved, new kitchen fitted, with the downtime kept as short as possible.

Completion & Sign-Off

Building control issues the completion certificate, and you get your gas, water and electrical certificates plus our written workmanship guarantee. The same project manager who did your first survey walks you through the finished room. Then you cook dinner in it.

Adds Space, Light & Value

The Heart Of The Home, Rebuilt Properly

Estate agents consistently rate the open-plan, garden-facing kitchen-diner as the most sought-after feature in a London family home, and it is not hard to see why: it is the room where cooking, eating, homework and everything else actually happens. A kitchen extension is the one project that improves every single day you live in the house, and done properly, with the structure and the kitchen designed together, it is also the improvement buyers pay most attention to when you eventually sell.

"Nobody ever wished their kitchen was smaller. Get the structure, the light and the layout right and the kitchen extension becomes the room the whole house revolves around."

Hiring Pitfalls

Red Flags When Hiring

Most kitchen extension disputes come from the same warning signs at quoting stage. Watch for these before you sign, ours included.

No Services Plan

Sink, hob, extraction and island positions decide where drainage, gas and electrics run. A quote that doesn't ask where your kitchen is going will move pipes twice, at your expense.

A "From" Price That Excludes VAT

Many kitchen extension quotes look cheap because the "from" figure leaves off 20% VAT, the steel or the fees. Ask for the all-in number. Ours is fixed and includes VAT.

Shell And Kitchen Blurred Into One Number

If you can't see what the build costs versus what the kitchen costs, you can't control either. We price them separately so you choose the spec with open eyes.

No Structural Engineer

Opening the back of the house needs proper steel and calculations. A quote with no engineer's input is guessing at the most critical part of the job.

Vague On Planning & Party Wall

The route decides whether you need an application, and a terrace or semi almost always triggers the Party Wall Act. A builder who waves both away is storing up delays and disputes.

No Address Or Recent Projects

Check Companies House and ask for recent local jobs. We are on Google and Checkatrade with a real Hayes address you can verify.

Where We Build

Kitchen Extensions Across West London & Surrey

From our Hayes base we cover West London, South-West London and Surrey: street after street of terraces and semis whose kitchens deserve better, and councils whose approach to extensions we know well.

UB · Hillingdon

Hayes, Uxbridge & Ruislip

Our home patch: semis and terraces where a rear kitchen extension creates the family kitchen-diner the original floor plan never allowed. See our Hayes page.

W3 · W5 · W13

Ealing, Acton & Hanwell

Victorian terrace country, where the side return kitchen extension was practically invented, with conservation pockets handled carefully.

TW · Hounslow

Hounslow, Isleworth & Chiswick

Period terraces and 1930s semis where a kitchen diner extension opens the ground floor to the garden, with planning routes we know well.

TW1 · TW9

Twickenham & Richmond

Sought-after period stock, often in conservation areas needing a full application, which we design for approval. See our Richmond page.

KT · Kingston

Kingston, Surbiton & New Malden

Semis with the width and gardens for bigger rear kitchen extensions, islands and full-width bifolds onto the garden.

Surrey

Esher, Cobham, Weybridge & Egham

Across the Surrey commuter belt, detached and semi-detached homes where generous plots take the largest kitchen extensions, planning handled for you.

Got Questions?

Kitchen Extension FAQs

It depends on what your kitchen lacks. A narrow galley in a terrace suits a side return kitchen extension, which adds width. A kitchen that is wide enough but too small suits a rear kitchen extension, which adds depth and is often permitted development. For the full open-plan transformation, a wrap-around combines both. We recommend the route honestly at a free survey.

The extension itself typically costs £48,000–£120,000 including VAT depending on the route: a small 2–3m rear extension £48,000–£65,000, a side return £60,000–£85,000, a 4–5m rear kitchen-diner £65,000–£95,000, and a wrap-around £95,000–£120,000. The kitchen fit-out is budgeted separately, typically £10,000–£30,000. We fix the build price in writing after a free survey. See our cost guide or try the free calculator.

Industry guides put a full UK kitchen installation at roughly £5,000 for a small budget kitchen, around £10,500 mid-range, and £28,000+ for a large high-end one (see Checkatrade), while London architect-led projects often spend £15,000–£60,000. For most West London kitchen extensions, £10,000–£30,000 buys a quality kitchen. We keep it separate from the build price so you control the spec, and we are happy to fit the kitchen you choose.

It depends on the route. A rear kitchen extension up to 3m (4m detached) is usually permitted development, and up to 6m/8m is possible with prior approval. A side return often needs planning, and always does in a conservation area. A wrap-around always needs a full application. We confirm your exact route at the survey, and where the work is PD we recommend a Lawful Development Certificate (£274) so you hold council paperwork proving it. More in our planning guide.

Most single-storey kitchen extensions take around 10 to 16 weeks on site, and a wrap-around 14 to 20. Before work starts there is a design and approvals stage covering drawings, any application and party wall notices, so allow a few months from first survey to breaking ground. We give you a realistic programme with the fixed-price contract, including exactly when the old kitchen comes out.

For much of the build, yes. The extension is built and made weathertight outside the existing wall first, so your kitchen usually keeps working through the early months. There is then a changeover period, typically a few weeks, when the wall opens, services move and the new kitchen goes in. We plan that stage with you in advance, keep it as short as possible, and set up a temporary kitchen area so you are never without the basics.

Usually, yes. Even 2 to 3 metres of extra depth or width transforms how a kitchen works: room for a dining table, a proper run of worktop, or a compact island. A small kitchen extension can often be built under permitted development with simpler structure, so the cost per square metre of change is excellent. Our free survey will tell you honestly what a small extension can and cannot achieve for your house.

Start with the working triangle, keeping the sink, hob and fridge close together and out of the through-route, then zone the room into cooking, eating and sitting areas. An island works from about 4 metres of room width and needs around a metre of clearance on each working side; a U-shaped kitchen suits narrower rooms. Fix the layout before the build starts, because drainage, extraction and electrics are far cheaper put in the right place first time. We design the layout with you at the drawing stage.

For a kitchen you use every day, a solid-roofed extension with generous glazing usually beats both. A conservatory swings too hot in summer and too cold in winter for reliable daily cooking. An orangery-style extension, meaning solid walls with a substantial roof lantern, gives you most of the light with far better insulation, built as a proper extension to building regulations. You get the bright, garden-facing feel without the greenhouse drawbacks.

Not usually with us. Signature Build is a design-and-build company, so our own team prepares the drawings, kitchen layout, structural engineering and any planning application in-house, which means you do not have to appoint and pay a separate architect first. For a highly bespoke scheme some clients bring their own architect or kitchen designer and we are happy to build to their design. Either way you get one point of contact and one fixed price.

Cook In A Room You Love

Book Your Free
Kitchen Extension Survey

Our project manager will visit, measure your kitchen, side return and rear, talk through the route, the layout and the planning position, and tell you exactly what it would cost, fixed in writing and including VAT, with planning and party wall handled for you. Or get an instant estimate with our free calculator.