At DWG Plans, the most popular service we provide for homeowners across the UK is the design of a single storey rear extension. This type of extension is by far the most economical and versatile way to add extra living space to your property. Whether you’re looking to create a larger kitchen, an open-plan family area, or simply more functional space, a rear extension offers the perfect balance of affordability, practicality, and design flexibility.

For many property owners, one of the first questions that comes to mind is: Do I need planning permission for a single storey rear extension in the UK? The answer depends on several key factors. In many cases, you may be able to build your extension under what are known as permitted development rights (PDRs). These rights allow certain types of home improvements and extensions without the need to go through the full planning permission process. However, your extension must meet strict conditions to qualify.

Permitted Development Rules for Single Storey Rear Extensions in England

To determine whether your project falls under permitted development, you’ll need to check the following criteria:

1. Height Restrictions

• The maximum overall height of your single storey rear extension must not exceed 4 metres.

• If your extension is built within 2 metres of a boundary, the eaves cannot exceed 3 metres in height.

2. Depth from the Original Rear Wall

• For a terraced house or semi-detached property, the extension can extend up to 3 metres beyond the original rear wall.

• For a detached house, the limit increases to 4 metres.

• Under the Neighbour Consultation Scheme, these depth limits may be increased to 6 metres for terraced and semi-detached homes, and up to 8 metres for detached properties. This requires prior approval from your local authority.

3. Materials Used

• The materials used for the exterior of the extension must be similar in appearance to those of the existing property. This ensures the extension blends seamlessly with your home’s design.

4. Additional Restrictions

• Your extension cannot be built in designated areas such as a conservation area, Area of Outstanding Natural Beauty (AONB), or if your property is a listed building.

• The extension must not cover more than 50% of the garden or land around the original property.

When Planning Permission is Required

If your proposed extension does not meet the criteria above, you will need to apply for planning permission. For example:

• If your single storey rear extension exceeds the maximum height or depth limits.

• If your home is located in a conservation area or is a listed building.

• If you intend to use different materials, or if the design includes features such as a balcony, veranda, raised platform, or decking.

Failing to secure the correct permission can result in enforcement action from the local authority, which may require costly alterations or even removal of the extension.

Why Apply for a Lawful Development Certificate?

Even if your extension appears to fall under permitted development rights, it is often advisable to apply for a Lawful Development Certificate (LDC). This certificate, issued by your local council, confirms that your single storey rear extension is legally compliant without the need for planning permission. Having an LDC provides peace of mind, ensures no future disputes with neighbours or buyers, and helps safeguard the value of your property.

At DWG Plans, we specialise in preparing detailed drawings and handling the submission of LDC applications on your behalf. Our team ensures your extension meets all the relevant requirements and provides a professional, stress-free process from start to finish.

Final Thoughts

A single storey rear extension is an excellent way to add space and value to your home without the high costs of moving. By understanding the rules around permitted development and planning permission, you can approach your project with confidence. Whether you need design support, drawings, or assistance with applications, DWG Plans is here to help you achieve your vision.

Check out our portfolio of single storey rear extensions that we have provided planning permission and building regulation drawings for.

Call DWG Plans on 0800 688 9345 or get in touch online today.