Wondering if you need planning permission for a 2-storey extension? In the UK, planning permission is often required for extensions, but some projects may fall under permitted development rights. 

Factors such as size, location, and proximity to neighbouring properties can affect the need for permission. This guide outlines the key regulations, exceptions, and steps to ensure your extension complies with local planning rules. 

Learn what you need to know about building restrictions and how to apply for planning permission if required.

What Are Permitted Development Rights?

Permitted Development Rights allow homeowners to make specific changes to their properties without the need to apply for planning permission. These rights aim to simplify the process of making modest alterations, such as extensions or conservatories, enabling homeowners to improve their living space without the lengthy and often complex approval process.

However, these rights come with restrictions and guidelines that must be strictly followed to avoid complications. Under Permitted Development Rights, a two-storey extension can be built under certain conditions. 

The rules for these extensions are detailed and subject to limitations revolving around size, location, and the impact on the surrounding area and neighbours. For example, the extension must not exceed a specific percentage of the original house size, and it must also conform to height and boundary restrictions.

Furthermore, there are additional factors to consider, such as the effect on privacy and light for neighbouring properties. The materials used in the extension must closely match the existing house to maintain consistency in appearance. It is also essential to ensure that the development does not obstruct any public rights of way. 

In certain areas, such as conservation areas or designated land, Permitted Development Rights may be more restrictive, and homeowners may need to seek additional permissions. 

It is advisable for homeowners to thoroughly check the specifics of these rights and, if necessary, consult with local planning authorities to ensure compliance. Ignoring these regulations can result in legal issues and potential enforcement action to remove or alter unapproved extensions.

What Are the Restrictions When Building a Two-Storey Extension?

Building a two-storey extension comes with careful rules to ensure that the extension is harmonious with the neighbourhood and does not infringe on the rights or quality of life of adjacent property owners. One of the key restrictions includes height limits. 

The height of the extension cannot exceed the height of the existing house. The maximum eaves and ridge height of the extension must not be higher than the existing house. For rear extensions, the extension must not extend beyond the rear wall of the original house by more than 3 metres for a semi-detached or 4 metres for a detached house. If the extension is closer than 7 metres to the rear boundary, further permissions may be required.

Additionally, the extension must be within two metres of the boundary for various types of properties like semi-detached or terraced houses. The design of the new roof is also important. The new roof pitch must match that of the existing house. 

The extension should not include balconies, verandas, or raised platforms. The materials used must be similar or match the existing house to ensure visual continuity and aesthetic harmony. This includes bricks, roof tiles, and renderings. In cases where the property is located within a protected area, such as a conservation area, national park, or area of outstanding natural beauty, stricter guidelines apply. 

You may need additional permissions to proceed with your extension. These restrictions are in place to maintain the character and appearance of such areas, preventing any construction that would disrupt their unique qualities.

Adhering to these regulations not only helps to maintain the aesthetic value of the area but also ensures that all nearby property owners retain their privacy and quality of life. Careful planning and consideration are essential to achieving a successful and compliant extension project. This way, you can enhance your living space without disrupting the harmony of the surrounding environment.

Do You Need Prior Approval?

Prior approval is an essential pre-application process that offers a way to confirm that your proposed extension meets specific regulations set by your local council. This process is particularly pertinent when you plan a development, such as a two-storey extension, that might not require full planning permission under permitted development rights.

Even in such cases, you could still be required to obtain prior approval to address various considerations such as the potential impact on your neighbours and the wider community. Several factors come into play during the council's assessment, including privacy, light, and the general visual impact on the neighbourhood. The process mandates notifying your neighbours and providing them an opportunity to voice any objections or concerns about your proposed extension.

If no significant objections are raised, or if the council finds the raised concerns to be unsubstantiated, your project can usually move forward. Engaging the services of an architect or consulting with your local authority is highly advisable to ensure that you meet all criteria and avoid any potential issues. 

An architect can offer professional guidance on whether your extension complies with permitted development rights and can help you navigate the prior approval process smoothly. Consulting with your local authority can provide additional peace of mind, ensuring that all guidelines are strictly adhered to, and that your building project progresses without any unforeseen complications.

What About Listed Properties?

Special guidelines apply to listed properties because they are protected due to their historical or architectural significance. If your house is a listed property, you will need to obtain listed building consent before making any changes, including a two-storey extension. 

This is crucial regardless of whether the extension falls under permitted development rights. Listed building consent is more stringent than standard planning permission because it aims to preserve the character and integrity of the original house and the surrounding environment. The process involves detailed scrutiny of the proposed materials, design, and impact on the listed property.

How Big Can I Build a Two-Storey Extension Without Planning Permission?

If you plan to build a two-storey extension without seeking planning permission, you must adhere strictly to the regulations under permitted development rights. The extension must not exceed the original house's rear wall by more than 3 metres for semi-detached or terraced houses and 4 metres for detached houses. 

Additionally, the extension must not be closer than 7 metres to the rear boundary of the property. The guidelines also stipulate that the height of the extension cannot be higher than the existing house, including the eaves and ridge height matching the original structure.

Furthermore, the materials used for construction must match the existing house to ensure uniformity in appearance. The roof pitch should also match that of the existing house. Uniformity in the look of the house contributes to an aesthetically pleasing appearance and can help avoid any potential complaints from neighbours regarding the visual impact. 

For two-storey rear extensions, ensure the windows on the upper floor use non-opening or obscure glass to maintain privacy for your neighbours. This is important to prevent any overlooking issues and to preserve the privacy of both you and the surrounding properties. Your local council might have additional guidelines, particularly if your house is in a conservation area or an area of outstanding natural beauty.

In these areas, restrictions are often stricter to maintain the character and beauty of the environment. It’s also crucial to consider any potential impact on nearby properties and how any building work might affect them. Ensuring neighbourly relations is essential. Before you start any construction, always check with your local authority or consult an architect to ensure your plans comply with all relevant rules and guidelines. 

An architect can provide invaluable advice and help you navigate the regulatory requirements, ensuring that your extension project proceeds smoothly and without any legal complications. Compliance with these regulations not only ensures legal adherence but also helps you create a well-planned extension that seamlessly integrates with the existing property.

Our team are on hand to discuss your two storey extension. Find out more via the link below.