Is planning permission required for a house extension?

Embarking on a house extension project is a significant decision for any homeowner. It’s an exciting journey towards creating more space and potentially increasing the value of your home. However, one of the first hurdles you’ll encounter is the question of planning permission. Understanding whether you need planning permission for your house extension can seem daunting, but it’s a crucial step in the process. This blog post aims to demystify the requirements and provide you with the information you need to proceed with confidence.


Understanding Planning Permission

Planning permission is a formal approval from your local planning authority, ensuring that your proposed extension complies with local development plans. Whether you need planning permission depends on various factors, including the size and location of your extension, and specific local and national planning policies.


Permitted Development Rights

For many homeowners, permitted development rights (PDR) provide a straightforward path to extending their homes without needing to apply for planning permission. PDR allows for certain types of work and alterations to be carried out without formal consent, subject to conditions and limitations.

Generally, single-storey rear extensions, side extensions, and loft conversions can fall within PDR, provided they adhere to specific guidelines regarding dimensions, materials, and positioning. For example, a single-storey rear extension on a detached property can extend up to 8 meters without requiring planning permission, while semi-detached and terraced houses are limited to 6 meters.

However, it’s important to note that PDR doesn’t apply universally. Restrictions are tighter in designated areas such as conservation areas, National Parks, Areas of Outstanding Natural Beauty, and for listed buildings. In these cases, almost all external work will require planning permission.


Article 4 Directions and Other Considerations

Local authorities have the power to remove some permitted development rights using Article 4 Directions. This is often implemented in areas of historical or architectural significance to maintain the character of the neighbourhood. If your property is affected by an Article 4 Direction, you’ll need to apply for planning permission for work that would normally be covered by PDR.

It’s also worth noting that any extension must not cover more than half the area of land around the “original house” as it was first built or as it stood on 1 July 1948 for older homes. Extensions must also not extend beyond the principal elevation facing a highway, and the materials used should be similar in appearance to the existing house.


The Process of Applying for Planning Permission

If your extension project falls outside the scope of permitted development, you’ll need to apply for planning permission. The application process involves submitting detailed plans and drawings of the proposed work to your local planning authority, along with a fee. The current standard fee in England for a householder planning application is £206.

The planning authority will consider your application, taking into account the impact on the surrounding area, any objections from neighbours, and whether the proposal aligns with local planning policies. The decision process typically takes 8 weeks for straightforward applications.



Deciding whether you need planning permission for your house extension requires careful consideration of your project’s specifics and an understanding of the local planning regulations. Start by determining if your project falls within permitted development rights, and remember to check for any Article 4 Directions or special designations that might affect your property. If in doubt, it’s always best to consult with an architect or planning consultant who can provide expert guidance tailored to your project.

For those embarking on a house extension project, navigating the planning permission landscape is a critical step. But with the right information and support, you can move forward confidently, turning your home extension dream into reality.

If you’re considering a house extension and unsure about the planning permission requirements, our team at Muirfield Construction is here to help. With our expertise in construction and planning regulations, we can guide you through the process, ensuring your project complies with all necessary requirements. Reach out to us now for a personalized consultation, and allow us to assist you in making your dream project a reality.