How much do kitchen extensions cost?
The kitchen extensions costs in this article are correct as of 2022
One of the most popular major home improvement projects people undertake is a kitchen extension. The central role of the kitchen in the way we use our homes mean they are often a focal point of the entire property, and making sure they’re big enough to handle everything you throw at them is important. A kitchen extension gives you more space and can even boost the value of your home, but you may be wondering how much an average kitchen extension costs, or how to go about getting kitchen extension quotes. Our guide will talk you through the price of a kitchen extension so that you’re ready to get started with your project.
Kitchen extension cost calculator
There are two key factors to consider when looking at the cost of a kitchen extension, the price of the building work involved in the extension itself, and the cost of the new kitchen. These can all be done as part of the same project by the same team of general builders, or carried out separately after finding specialist extension builders followed by kitchen fitters.
Speaking to our experts, we have established that the basic price of building an extension is £1,100 to £1,400 per square metre. So, for a 20msq extension (4m x 5m), the cost will range from £22,000 to £28,000. These prices don’t include VAT, charged at 20%. The price bracket reflects the variance of materials used, the complexity of design, quality of finish and where in the UK you live. This price covers the essential elements of the build, constructing the foundations, building the walls, insulating the new structure, fitting out with plasterboard, adding a subfloor, and installing a basic provision for plumbing and electrics.
The kitchen element will depend on the quality and the materials you wish to use, and the size of the kitchen being installed - the number of units you will need, and the size of the work surfaces for example. After speaking to experienced MyBuilder.com tradespeople around the UK, we estimate that the average price of a new kitchen installation in the UK costs around £5,000 to £6,000. At the lower end of the spectrum, it can be possible to purchase and install a new kitchen from around £1,200. At the high end, the price can be limitless depending on your specifications, but a top of the range kitchen may cost around £14,000. Prices will generally be higher in London and the south east where tradespeople can charge a premium for their time.
In total then, the average cost of a kitchen extension will be around £30,000.
For more details on the cost of building an extension, you can read our full guide on how much a home extension costs.
For a detailed look at the costs involved in fitting a new kitchen, check out MyBuilder’s guide to kitchen installation costs.

How long do kitchen extensions take to complete?
The amount of time it takes to construct a kitchen extension will obviously depend on the scale of the build. A rough time-frame would be between three and four months, from the start of the project - clearing the space and digging the foundations, adding the finishing touches, and dealing with any snags you encounter. This does not include time for drawing plans and obtaining planning permission, if necessary. Delays can be common, and are often due to bad weather, changes in the plans, and hold-ups in materials being delivered. With multiple trades working on an extension, backlogs can also occur, with certain elements relying on other parts to be completed first.
MyBuilder Top Tip
At MyBuilder, we tend to advocate for hiring specialists in their particular fields to help make sure a job is done well. When constructing a kitchen extension, you may want to hire kitchen fitters separately from the firm that builds the extension, particularly if it’s a high-end kitchen which requires particular skill and attention to fit and working with specialist materials such as a granite or marble. However, an experienced extensions firm may be able to carry out the entire job from start to finish - make sure you ask to see examples of their previous work so you’re happy that they are up to scratch.
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How to keep your kitchen extension costs under control
There are a number of ways to ensure you’re getting value for money when building a kitchen extension. The most important thing is ensuring you hire tradespeople who are reliable and trustworthy, and who you’ll have good communication with. It’s easy to find quality tradespeople on MyBuilder, with reviews from their previous customers. You should meet with multiple extension builders to get kitchen extension quotes and get a range of how much the project will cost to complete.
It is important that you only embark on any major project, like building an extension, when you are fully aware of scale of the job and the costs involved. Set a budget and get several quotations for the work. Allowing yourself a contingency is always a wise move, to help you cover any extra expenses that could arise as a result of delays or issues with materials.
If you’re buying the kitchen yourself from a store or online, make sure you shop around and compare prices, and look out for deals in sales, which will be held throughout the year.