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London home extensions: What you need to know


17 Feb 23

Extending a home in London can be a great way to add space and value to your property. Whether you need an extra bedroom, a larger living room, or a new kitchen, a well-designed extension can transform your home and enhance your quality of life. However, extending a home in London can also be a complex and challenging process, with many factors to consider. In this article, we will explore the key things you need to know before extending your home in London.

Planning Permission

One of the first things to consider when extending a home in London is planning permission. Depending on the size and nature of your proposed extension, you may need to apply for planning permission from your local council. Planning permission can take several weeks or months to obtain, so it is important to factor this into your project timeline.

In general, planning permission is required for any extension that is larger than 50 cubic metres or extends beyond the rear of the original house by more than three metres. However, there are many other factors that can affect the need for planning permission, such as the location of the property and any conservation area or listed building status. It is always a good idea to consult with an architect or planning consultant to determine whether planning permission is required for your project.

Building Regulations

Even if your extension does not require planning permission, you will still need to comply with building regulations. Building regulations ensure that any structural alterations to your home meet the necessary safety and health standards. Building regulations cover a wide range of aspects, such as insulation, ventilation, fire safety, and accessibility. It is important to ensure that your builder is aware of the relevant building regulations and complies with them throughout the construction process.


Extending a home in London can be an expensive process, and it is important to set a realistic budget for your project. The cost of a home extension in London can vary widely depending on the size and complexity of the project, the materials used, and the location of the property. In general, the cost of a home extension in London can range from £1,000 to £3,000 per square metre.

When setting a budget for your project, it is important to consider all the costs involved, such as design fees, planning application fees, building regulation fees, materials, and labor. It is also important to set aside some extra funds for unexpected expenses or unforeseen problems that may arise during the construction process.

Finding the Right Builder

Finding the right builder for your home extension project is crucial for the success of the project. It is important to choose a builder who is experienced in home extensions and who has a good reputation. You should always ask for references and check online reviews before choosing a builder.

It is also important to ensure that the builder is properly licensed and insured. A good builder will provide a detailed written contract that outlines the scope of the project, the timeline, and the costs involved. It is important to read and understand the contract before signing it.


The design of your home extension is another important factor to consider. A well-designed extension can enhance the functionality and aesthetic appeal of your home, while a poorly designed extension can detract from the overall value of your property.

When designing your home extension, it is important to consider the purpose of the extension and how it will be used. It is also important to consider the style of your existing home and how the extension will blend in with the overall look and feel of the property.

In addition to the design of the extension itself, it is also important to consider the design of the surrounding landscape. A well-designed garden or outdoor space can enhance the overall appeal of your home and add value to the property.


Finally, the timeline for your home extension project will depend on the size and complexity of the project, as well as factors such as planning permission and building regulations. It is important to work with your builder to create a realistic timeline for the project and to ensure that all deadlines are met.

In general, a home extension project in London can take anywhere from three to six months or more. It is important to plan ahead and to allow plenty of time for each stage of the project, from design and planning to construction and finishing.


Extending a home in London can be a great way to add space and value to your property. However, it is important to carefully consider all the factors involved, from planning permission and building regulations to budget and design. Working with an experienced and reputable builder can help ensure the success of your home extension project, and careful planning and preparation can help ensure that the project is completed on time and within budget. With the right approach, a home extension can transform your London home into the perfect living space for you and your family.

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