As a general rule, prices for high-quality kitchen extensions start at around £65,000. For more ambitious projects, they can cost £120,000 or more. This might seem like a wildly-varying range, but there are many variables to take into account. In this post, we explain what some of these are, as well as the many benefits of installing a kitchen extension. 

Why build a kitchen extension?

The kitchen is the hub of the home. It’s where we prepare ourselves for the day ahead and where we gather in the evenings to unwind. As the most multifunctional room in the house, it serves many different purposes; from being the place where we cook and eat to providing an informal area for hosting family and friends. 

A kitchen extension is sure to maximise living space, giving growing families extra room to use whilst rejuvenating the overall feeling of a property. It can also increase the value of a home by as much as 20%, not to mention its saleability.

How much is a kitchen extension?

A kitchen extension can cost anything from £65,000 to over £120,000. How much yours will cost is determined by three factors: design, size, and type.


A kitchen extension is more than an expansion of your existing kitchen space. It’s a re-imagining of it. With a kitchen extension, you can entirely re-design the ground floor of your property; you may want to create an industrial feel through the use of reclaimed materials, a modern space with clean lines, or an intimate enclave through warm colours and textures. A kitchen extension allows you to re-frame the focus of your property whilst improving its functionality.


Kitchen extensions come in all shapes and sizes. Some help you to take advantage of an unused walkway by the side of your property, whilst others expand into areas on multiple sides of your house. Regardless of its size, a kitchen extension provides more space for your needs and the opportunity to refresh your property’s style. 


There are several different types of kitchen extension. Which one you choose depends on the shape and suitability of your property, not to mention your design ambitions. Here are the most common kitchen extension types offered by Plus Rooms along with some examples of our previous projects.

Rear kitchen extension

A rear kitchen extension expands into available space behind a property. Suitable for most house types, it widens the design potential for kitchen/diner areas whilst allowing more natural light to spill into other rooms on the ground floor.

Whilst the costs of a rear kitchen extension vary according to roof type, they generally start at around £70,000. 


Side return kitchen extension

A side return extension expands the kitchen space into unused areas adjacent to the property, such as a garden walkway.

A viable option in areas with tight planning permission, side return extensions are often used to enhance Victorian terraced properties and take advantage of the unused space at the side of the kitchen. The average cost of a side return kitchen extension is £65k.


Dassett RD (SE27) – This modest side return extension has a significant impact on the property, creating a unique space that blends traditional and contemporary aspects such as a parquet floor with copper pipe shelving.

Derwent Grove (SE22) –The exposed brickwork of this project provides warmth to a modern kitchen space filled with natural light.

Side and rear kitchen extension

This type of extension expands into areas both to the side and rear of your property. Whilst similar to a wraparound extension (more on this below), it allows owners to create more separated spaces within their home. Prices for side and rear extensions start at around £80,000.


Garfield Rd (SW19) – This side and rear extension in Wimbledon overcomes local planning permission issues and provides a modern kitchen/diner space with neat lines, an abundance of natural light, and occasional splashes of colour. Its broken plan layout helps to create interesting and specific zones to the space.

Wraparound kitchen extension

Wraparound kitchen extensions also expand into the side and rear of a property.

Unlike a side and rear extension, however, wraparound extensions are conjoined; they move into areas on two or three sides of a house, often creating a significantly larger indoor space. Prices for wraparound kitchen extensions start at around £85,000 


Nigel Rd (SE15) – Making use of space to the rear and side of a Victorian terraced property, this extension creates a bright contemporary kitchen/dining area through clean lines and frameless skylights.

Fellbrigg Road (SE22) – ‘Crittall’ style doors have been paired with exposed brick walls and a navy shaker kitchen to create an open, light Art Deco/Industrial space. 

Read more about building regulations in the UK.

An investment in your home 

A kitchen is much more than a purely functional space. Although it has numerous uses, it can also be considered an expression of your way of living. As such there are many options when it comes to kitchen extensions, and each has an impact on its final cost. Regardless of property type and stylistic leanings, however, one thing is certain; a kitchen extension will enhance your home immeasurably.

Plus Rooms is a family-run business that focuses on improving people’s homes through beautifully designed extensions. We manage all aspects of extension projects, from initial design work through to planning permission, party wall notices, and construction. To learn more about our work, check out extension case studies or send us a message, we’re here to answer all of your questions.