Need an Estimate?
Get a Price

Kitchen Extension Cost

In the following cost guide, we’ll explore topics such as how much the different types and sizes of kitchen extensions will cost you, how long this work could take and what building a kitchen extension entails.

8-10 weeks
Avg price:
£1200-£2000 pm²

Introduction to Kitchen Extensions

Are you planning to add an extension to your kitchen? With such an addition, you can create more space for dining, relaxing, watching TV and hosting guests, among other uses.

Beyond that, a kitchen extension can alter the entire feel and look of your home.

This article will prove particularly useful if you intend to have an extension added to your kitchen or if you’re considering the prospect for a later date. Kitchen extensions involve expanding the size and utility of a kitchen by constructing an additional structure beyond the current kitchen.

Alternatively, a wall between an existing kitchen and living room may be taken away as to extend the space used as a kitchen. The increased space and functionality of an extended kitchen are the main reasons for the popularity of kitchen extensions.

How Much Does a New Kitchen Extension Cost?

On average, it will cost you somewhere between £1200 to £2000 per square metre to have a kitchen extension added. There are, however, various factors to consider.

For instance, it could cost anywhere from £15,000 to £70,000 in total to have a rear kitchen extension constructed. It might set you back around £30,000 to £50,000 altogether to have a side return kitchen extension created.

A wrap-around kitchen extension will on average set you back between £40,000 to £60,000 while the average cost for a kitchen diner extension could end up around £30,000 to £60,000 as your overall bill.

As for the scale of the extension, for a small kitchen extension, it may cost between £15,000 and £20,000, a medium extension may set you back around £20,000 to £35,000 while a large kitchen extension may land in the £35,000 to £70,000 range. This assumes the use of basic or standard quality materials.

If you were to employ premium quality materials, then you can expect the aforementioned costs to rise by around 30-70%. The labour costs will likely make up about 45% of the total costs with half of the total expenses being down to the materials and the remaining 5% being attributed to waste removal.

This is, of course, a broad approximation, and it could vary significantly from job to job. The hourly cost per contractor will probably be around £60 to £70. For a kitchen fitter, you’ll likely pay around £35 to £45 per hour while the services of a plumber or electrician will probably cost between £50 and £60 per hour.

With the waste removal cost landing around 5% of the total, this expense will likely end up about £750 to £1000 for a small extension, £1000 to £1750 for a medium extension or about £1750 to £3500 for a large extension.

The overall cost will be influenced not only by the type and size of extension but also whereabouts you are located and ease of access. The reason why location matters is due to the fact that labourers charge different rates in different parts of the country.

While professionals in London and the southeast of England have higher rates, the costs are lower if you’re based in say the north of England.

In addition, the quality of the materials and appliances you wish to have installed will also shape the total cost.

Further, you may decide to hire a designer to help you plan out your kitchen extension before any work gets underway.

In this regard, the complexity of the design and the rate set by the designer will also factor into overall costs. These estimates are most applicable to the price of a single-storey kitchen extension, as the total cost will be higher if you’d like to have a double-storey extension constructed.

Costs for Different Types of Kitchen Extensions:

Rear £15,000 to £70,000
Side Return £30,000 to £50,000
Wrap Around £40,000 to £60,000
Kitchen Diner Extension £30,000 to £60,000

Costs for Different Sizes of Kitchen Extensions (average/standard quality):

Small £15,000 to £20,000
Medium £20,000 to £35,000
Large £35,000 to £70,000

Choosing a Kitchen Extension

In this section, we’ll break down the details, costs and pros and cons of the various types of kitchen extensions. Additionally, we’ll consider which are the most popular/unpopular types, how easy they are to install and which are the cheapest and most expensive options.

Rear Kitchen Extension Cost

This type of extension involves a structure being added to the back of a house, to, in turn, extend the kitchen such that it protrudes outwards into the garden. The cost of a rear kitchen extension could range from £15,000 to £70,000.

A rear kitchen extension is generally the easiest ways to extend a kitchen. However, unlike a side return extension, it is only suitable if you have enough space behind your house. This type of extension is also particularly popular.


✔ Often the cheapest option.

✔ One of the easier extensions to construct.

✔ Suitable for most properties.


✖ May run into problems if you have limited garden space.

Side Return Kitchen Extension Cost

On the other hand, you may wish to have your kitchen extended to the side of your property. Of course, there may be more implications to consider for both you and your neighbours should you have a side return kitchen extension created.

The cost of an extension that is built to the side of a house could end up between £30,000 and £50,000. You’ll need to take into account how you’d like to use the side windows of your property and whether their view may be obstructed with such an extension.


✔ Suitable if you have space to the side of your home.

✔ Great alternative if you lack space at the back of your property.


✖ May block a side entrance to your home.

✖ Could be costly.

Wrap Around Kitchen Extension Cost

You may also be interested in a wrap-around kitchen extension. In this case, both a rear and side return extension are constructed and combined to create an especially large kitchen extension.

They are suitable for most detached and semi-detached houses. You’ll probably pay between £40,000 and £60,000 if you’d like to have this type of kitchen extension created.

However, it could cost a lot more, depending on the quality of the materials and the scale of the project, among other cost-affecting factors. A wrap-around kitchen extension will generally be one of, if not the most complex options to choose from.


✔ Large extension.


✖ Could prove particularly expensive.

✖ Complex job.

✖ Generally a time-consuming option.

Kitchen Diner Extension

Alternatively, you may wish to create an open plan kitchen diner. This design option has grown in popularity in recent years. They can be created in the form of a wrap-around or rear extension.

It’s an ideal choice if you’d like to have a large dining table and kitchen island as it will provide plenty of room in the middle.

You should also consider opening the kitchen up to your garden, such as with bi-folding doors. This would make for a perfect kitchen/garden space to use during warm summer days.

The cost of a kitchen extension based on this design could end up anywhere from £30,000 to £60,000 or more as the type of extension and complexity of the design will play major roles in determining the price.


✔ Creates a large open space.

✔ Perfect for a large dining table and kitchen island.


✖ Could prove costly but it will depend on a variety of factors.

What Does Building a Kitchen Extension Involve?

Let’s take a look at what building a kitchen extension entails.

1. Design Plans and Legal Approval

Before any work can begin, there are plenty of choices you’ll need to make and a lot of planning required.

To begin with, you’ll need to decide, broadly, what type/design of kitchen extension would interest you. It’s important to consider what you want to gain from extending your kitchen.

There are many kitchen extension ideas worth considering. You should consider a variety of questions such as, how would you like to use the space?

Also, what utilities will you add? And what look and feel would you like to add to your kitchen by having it extended?

At this point, you should hire an architect or a professional designer to help you determine the more integral details of your proposed kitchen extension. When it comes to hiring a designer or architect, you need to take this into account when considering your overall budget.

It’s important that you get some references and check for any guarantees and insurances that an architect or designer offers before deciding to hire them.

Don’t forget to also research how planning permission and building regulations might apply. Ensure that you undertake the proper research first, such as figuring out whether your permitted development rights (PDRs) will cover the planned extension or if you’ll need to acquire approval from the council.

Even if your PDRs apply, you’ll still need a building control officer to grant your project building regulations approval. Planning permission and building regulations approval as well as hiring a building control officer could each add to the overall costs of the project.

2. Hire a Builder and Additional Preparations

Once your design plans have been formulated, you should get in touch with contractors or building companies and obtain quotes from them. Once you’ve done this, you can select one to take care of the construction of your kitchen extension.

If you have only been in contact with an architect, you may want to consult a professional kitchen designer before finalising construction plans. Prior to hiring contractor(s), ensure that you get references first and check for appropriate guarantees and insurances.

If you hired an architect, per the previous step, they could also help you find a reliable and appropriate contractor.

3. Construction

Once everything is in place, work can begin on the creation of your kitchen extension. The various types of kitchen extensions are constructed differently.

While a rear kitchen extension involves extending your kitchen outwards, a side kitchen extension involves adding structure to the side of your property.

A wrap-around kitchen extension, as discussed earlier, combines both options. If you’d like a kitchen-diner extension, then the construction will involve creating enough central space to allow for your preferred vision.

Regardless of the type, a kitchen extension is usually built with bricks and mortar. However, some extensions are constructed more so with other materials such as copper, wood and even glass (i.e. a conservatory).

As for kitchen cabinets, they will first need to be mounted before the wall plugs, and doors can be fitted. Each type of cabinet will have a different installation process to the other, and the exact fitting instructions will vary from product to product.

For example, custom cabinets may be more challenging to fit depending on how complex their design and structure is.

Sinks can generally be fitted by connecting it to the pipework, sealing it in place with caulk and attaching clips to its underside. The exact details will vary depending on the style and type of sink concerned.

Other appliances and fittings which might be installed as part of the job include a new fridge, freezer, range cooker, kitchen island and countertops. A kitchen island must be fitted to the floor to ensure that it stays firmly in place.

The base will be added first before the top is installed. A similar process is involved with the installation of countertops in general. As for more additional costs, structural engineer fees and those associated with the groundworks could also apply.

4. Finalisation and Clean Up

Once the work is complete, finishing touches can be added to your extension, such as to make it clean and shiny before use. At this stage, there will be a lot of material and waste that will need to be cleared and removed.

A skip or a man and van service will probably be needed for this phase of the project unless the company/contractors you’ve hired have already agreed to take care of the waste removal in full by themselves.

It’s vital that you figure these things out before work commences.

DIY Kitchen Extension Installation

It is possible to construct a kitchen extension DIY. However, there is certain work that legally you cannot do by yourself, such as those that involve electrics. So, you may find that your kitchen extension ideas cannot be brought to life DIY or that at least some parts of it must be dealt with by professionals.

As for building regulations, they can cover a range of subjects related to fire safety, drainage, electricity, access and insulation.

In terms of planning permission, your permitted development rights allow you to do so much before approval is required.

The following rules must be followed to avoid planning permission;

  • No more than half of the land area surrounding your property may be covered by an extension.
  • Your kitchen extension may not be taller than the tallest part of the roof or taller at its eaves than your property’s existing eaves.
  • If your extension is situated within two metres of the edge of the curtilage of your property, the eaves height may not stand above three metres.
  • You may not have a kitchen extension constructed ahead of the principal elevation of your home or the side elevation in cases where the property fronts a highway.
  • Such work may not include a microwave antenna, chimney, flue pipe, soil and vent pipe, verandas, raised platform, balcony or any kind of alteration to your property’s existing roof.
  • If your home is located on article 2(3) designated land, the exterior of your property/extension may not feature cladding.
  • The materials utilised for the exterior work on the extension need to have a similar appearance to those used for the existing house exterior.

If your proposed extension would break these rules, then you must gain planning permission. Further restrictions apply if you would like a two-storey kitchen extension constructed.

You will need to notify building control about your project, and a building control officer must come by to check that the minimum standards have been reached in accordance with the building regulations.

There are, of course, a variety of risks and hazards involved in building a kitchen extension by yourself.

For instance, you may execute the work incorrectly and end up requiring contractors to come in and perform costly repairs to fix what you got wrong or/and complete the job for you.

Beyond that, if you do not take adequate safety measures or fail to do so correctly, then you risk building material falling on top of you or if using a ladder or otherwise standing at a height, there is a danger of falling and injuring yourself.

If you have any doubts, you should hire professionals to perform the work.

Potential Problems and Pitfalls

There are, of course, always risks involved, even if the work is performed by a professional. For one, you could unknowingly hire inexperienced or dodgy contractors who do not perform the work right but still charge you a substantial fee.

While thankfully, this is rare, by researching a contractor or/and company beforehand, you should be able to avoid hiring the wrong people. Even if all goes well, there are still some cons to consider with having a kitchen extension built.

Here are some of the disadvantages of a kitchen extension;

  • Expensive (you’ll likely be paying tens of thousands of pounds in total).
  • Time-consuming.
  • Disruptive.

If you fail to get planning permission or building regulations approval, you’ll need to spend time and likely money having new plans drawn up, which would also prove inconvenient.

sam jones profile

Sam J

We have hundreds of homeowners each day checking the prices on YourJobCost before hiring a tradesperson. That way they've already got a good idea of how much they should be quoted.

Ready to Get a Quote?

If you're ready to get some prices for your job, complete our form and compare trusted trades near you!

Get a Free Estimate