What Size Extension Can I Build Without Planning Permission?
In the UK, an extension to a house requires planning permission as part of the Building Regulations process. People generally look to build extensions in order to add more space to their property, and while this is permitted under certain circumstances, there are limitations on the size of an extension that can be built without planning permission. The limitation of building an extension without planning permission is known as a ‘permitted development’, and it is important to know the rules and regulations before starting any project.
The first step to determining what size extension can be built without planning permission is to understand the relevant legislation. The Government has set out permitted development rights so you don't always need to apply for planning permission when carrying out certain types of work.
Do I Need Planning Permission for an Extension?
The answer to this question is determined by the location of the property and the size and type of the proposed extension. Generally, the size and shape of the extension that can be built without planning permission will be different in urban environments compared to rural areas.
It is important to note that planning permission will still be needed even when the extension is within the permitted development limits as stated by the government. Many extensions in urban areas are subject to other restrictions, such as those imposed by local councils. In this case, you may require planning permission if the planned size of the extension exceeds the permitted development limits.
Need assistance finding extension builders near you?
Get a QuoteHow Big Can You Build An Extension Without Planning?
The rules for extending a house without planning permission are set out in the Government’s Building Regulations. These regulations determine the size of an extension that can be built without planning permission. It is essential to ensure the size of the extension does not exceed the permitted development limits, which vary depending on the type and size of the extension.
At the time of writing, the size limit for a single-storey extension is 8m x 4m in the majority of cases. For a two-storey extension, the limit is 4m x 4m. Extensions larger than these sizes are likely to require planning permission. Nevertheless, it is advisable to confirm with your local authority in all cases.
What Are The Single-Storey Extension Rules?
When building a single-storey extension, the maximum height of the eaves should not exceed 3 metres on detached houses and 4 metres on semi-detached or terraced properties.
Furthermore, in order to comply with planning rules and regulations, the eaves must not extend past the front of the existing house by more than three meters, nor should the eaves be closer than one metre to any boundaries. The extension must also be a single-storey and should not exceed more than half the width of the original house.
It is important to take into account any outside features such as trees and garden walls as these may also be subject to planning permission.
Multi-Storey Extensions
Multi-storey extensions are a great way of increasing the space in your home, but they often require planning permission.
If you are looking to build a multi-storey extension, the most important thing is to adhere to the permitted development limits. A single-storey rear extension cannot exceed 4 metres in depth and a two-storey extension should not exceed 3 metres in depth. It is also important to adhere to the maximum height of the eaves as outlined above.
It is essential to research the relevant legislation before commencing any project, and you should contact your local planning authority to check whether any additional requirements need to be met.
Overall, it is possible to build an extension without planning permission if you are mindful of the size and type of construction. However, it is important to ensure you comply with the necessary legislation, as failure to do so could result in costly fines or even the need to demolish the extension.
In this article:
