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London House Extension Cost Calculator

Planning a House Extension? Simplify Your Budget with Our Quick Cost Calculator. Effortlessly estimate your project's expenses in just a few easy steps.

Our intuitive tool provides a detailed extension cost estimate, making your planning process smoother. Start your journey towards a seamless house extension project with our efficient, user-friendly calculator today.

Unlock the potential of your home with precise, tailored cost insights that empower you to make informed decisions and bring your dream extension to life.

London house extension calculator

Ecron Ltd is a London based house extension company. We specialise in all types of house extensions including kitchen extensions, double storey, side return and wrap around extensions.

Why choose us for yours home extension project?

House extension guarantee

Extensions Guarantee

Insurance backed guarantee options for your peace of mind.

Insured extensions builders

Insured Company

We are fully insured. Choose safety and  work with Ecron.

Reliable extensions builders

Reliable Builders

Our goal is to deliver great results on time and budget.

Our clients' video testimonials reveal everything about our home extension projects. See their stories with Ecron Ltd.

Discover the quality of our work through testimonials from satisfied clients on our YouTube channel, showcasing the successful house extension projects we've delivered.

Following our comprehensive house extension services, Ecron Ltd is proud to offer a diverse portfolio to meet all your building needs in London and Surrey area. 

Enhancing Your London Home with Expert House Extensions Company.

In the bustling city of London, homeowners are constantly seeking innovative ways to maximize their living space and elevate their property value. House extensions, ranging from rear additions to sophisticated loft conversions, offer a tailor-made solution to meet these needs.


Whether you're dreaming of a sunlit kitchen diner that opens up to your garden or an additional bedroom for your growing family, there's an extension type to fit every London home. This blog post explores the variety of house extension options available, guiding you through making the most of your property's potential.

london house extension company

Our comprehensive list of building services includes the following:

Rear Extensions: Creating Seamless Indoor-Outdoor Living Spaces

rear house extension

Rear extensions stand out as a popular choice among London residents, extending the back of the property into the garden area. Ideal for those looking to enhance their kitchen or dining space, this extension type not only adds valuable square footage but also bridges the gap between indoor comfort and the beauty of outdoor living. By choosing a rear extension, you can transform your property into a haven of natural light and open space, perfect for modern family life and entertaining.

Side Return Extensions: Maximizing Narrow Spaces

For homes with limited outdoor space, the side return extension offers a clever solution. Utilizing the often-underused alleyway alongside the property, this extension type is perfect for expanding your kitchen area without sacrificing precious garden space. Side return extensions are especially suited for terraced and semi-detached houses in London, enhancing functionality and aesthetic appeal with minimal disruption to your outdoor areas.

side return house extension

Wrap Around Extensions: The Ultimate Space Enhancer

wrap around house extension

Wrap around extensions represent the epitome of transformative living space expansion, combining the benefits of rear and side return extensions. By extending along both the side and the rear of your property, you unlock unprecedented ground floor space, ideal for creating expansive, open-plan living areas. This type of extension is a game-changer for homeowners looking to revolutionize their living environment with a modern, airy feel.

Double Storey Extensions: Elevating Space and Value

Double storey extensions are a transformative investment for London homeowners seeking to substantially increase their living space and property value. By extending both the ground and first floors, these extensions provide a versatile solution to meet the evolving needs of any household. Whether you're in need of additional bedrooms, bathrooms, or expansive living areas, a double storey extension delivers on both functionality and style.

double storey extension

Single-Storey Extensions: Seamless Style and Garden Connectivity

single storey extension

Single-storey extensions are a cornerstone of modern London home renovation, offering a straightforward yet impactful way to enhance your living space. Perfect for those looking to expand their kitchen or create an expansive living area, these extensions blend the indoors with the outdoors, creating a harmonious living environment that capitalizes on natural light and garden views. The appeal of single-storey extensions lies in their ability to transform the functionality and aesthetic of your home without the need for a second-level addition.

Over-Structure Extensions: Space Without Sacrificing Garden Areas

Over-structure extensions represent a strategic approach to expanding living space in London homes by building over an existing structure, such as a garage, kitchen, or extension. This innovative method allows homeowners to add valuable living areas to their property without encroaching on precious garden space, a commodity in urban environments. By leveraging the foundation and walls of existing structures, these extensions offer a cost-effective and less intrusive way to increase your home’s square footage.

over structure extension
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How to use our free online extension cost calculator.

Get your extension cost estimate now in few easy steps !

Step 1

Select the Extension Type

Start with selecting the extension type that best fits your needs: rear, infill, or wrap-around. Rear extensions add space to your home's back, infill extensions fill unused spaces, and wrap-around extensions extend both the side and back for maximal space increase. This decision impacts your project's scope, design options, and initial cost estimate. Consider what you wish to achieve with your extension—whether it's more kitchen space, an additional living area, or something else—to guide your selection. This first step is essential in setting a clear direction for your extension project and using our calculator effectively for a preliminary budgeting insight.

Step 3

Select Finishes and Installations

Choose the finishes and installations for your extension, such as electrical and plumbing setups, wall finishes, and flooring types. These choices significantly affect both the functionality and aesthetics of your new space, as well as the overall cost. At this point, consider the quality and style that match your existing home or desired look. This will help provide a more accurate cost estimate and ensure that your extension feels cohesive with the rest of your property.

Step 2

Gather Approximate Dimensions:

Now, it’s time to roughly measure the area you wish to extend. Precision isn’t necessary at this point—just aim for ballpark figures. Measure the length and width of the space for your planned extension, and don’t forget about the height, especially if you’re considering a multi-storey extension. These initial, approximate measurements are crucial for the next steps. They allow our calculator to provide you with a preliminary estimate of the project costs, enabling you to start financial planning early on. Understanding the general size of the extension helps in shaping your project's vision and sets the stage for more detailed planning and consultations with professionals. 

Step 4

Obtain Your Estimate

With the details of your extension type, approximate dimensions, and selected finishes and installations ready, use our calculator to get your cost estimate. You'll have options for a fixed price, which offers cost certainty for the entire project, or a daily rate price, which might vary based on the actual work duration and materials used. This step gives you a clearer understanding of potential costs, allowing you to make informed decisions on how to proceed with your project within your budget.

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