Permitted Development Rights for House Extensions

Introduction to Permitted Development Rights

When extending a house in the UK, understanding Permitted Development rights is essential. These rights allow certain building works and changes to be carried out without the need for a full planning application, streamlining the process and enabling projects to commence more swiftly. But what exactly does Permitted Development entail, and why is it so important in the context of house extensions?

Permitted Development rights are a national grant of planning permission which allow specific types of work to be performed without the need to apply for planning permission, provided they meet certain criteria. This can cover everything from small home improvements to larger extensions. However, while these rights offer a significant advantage by cutting through bureaucratic red tape, they come with their own set of rules and limitations that must be carefully navigated.

In this blog post, we’ll look at the process of Permitted Development for house extensions in England, exploring the benefits, limitations, and key considerations that architects need to know. Whether you’re planning a modest addition or a more ambitious extension, this guide will equip you with the knowledge to navigate the Permitted Development pathway with confidence.

01 Introduction to Permitted Development Rights

What is Permitted Development?

Permitted Development refers to a set of planning rules in the UK that allow certain types of building works and changes to be made to a property without the need to apply for planning permission from the local authority. This legislative framework is designed to simplify the planning process for minor and moderate developments, facilitating homeowners and architects in enhancing and extending properties within predefined parameters.


Categories of Permitted Development

Permitted Development rights cover a wide range of works, including but not limited to:

  • Extensions to the rear or side of a house
  • Loft conversions
  • Changes to the roof
  • Installation of solar panels
  • Construction of outbuildings such as sheds or summer houses for purposes incidental to the enjoyment of the dwelling house
02 What is Permitted Development

Scope of Permitted Development for House Extensions

Permitted Development rights for house extensions in England are designed to enable homeowners to expand their living space without entangling themselves in the often lengthy process of obtaining planning permission. The requirements vary according to whether the extension is to a terraced house, semi detached house, or detached house. Permitted development does not apply to flats and maisonettes.


Types of Extensions Covered Under Permitted Development

Permitted Development rights typically cover several types of extensions, including:


Rear extensions

Single-storey rear extensions on detached and semi-detached properties can extend a certain distance from the original rear wall of the dwelling, subject to specific limits.


Side extensions

Single-storey side extensions can be constructed up to half the width of the original house, with height restrictions to ensure they are subservient to the main property.


Two-storey extensions

Under certain conditions, it’s possible to add a two-storey extension to the rear of the house, though this comes with stricter criteria regarding distance from boundary lines and height.


Key Measurements and Limitations of Permitted Development

Height: Extensions must not exceed the height of the existing house. Single-storey rear extensions should not be higher than 4 metres, and two-storey extensions must not exceed the height of the original house.

Depth: The maximum depth of a single-storey rear extension varies by property type; for detached houses, it’s typically 8 metres, and for semi-detached or terraced houses, it’s 6 metres. Two-storey extensions have more restrictive limits, usually not extending beyond 3 metres from the original rear wall.

Volume: Specific volume limits apply to the extension of the original house, ensuring that the development is proportionate to the existing structure.


Material Considerations

The materials used in the extension must be similar in appearance to those of the existing house. This requirement ensures that the extension blends with the original building, maintaining the aesthetic coherence of the property.


Protected Areas, Designated Land and Exceptions

It’s crucial to note that Permitted Development rights may be restricted or removed in certain areas, such as conservation areas, Areas of Outstanding Natural Beauty, World Heritage Sites, and for listed buildings. In these cases, specific permissions are usually required, even for developments that would otherwise fall under Permitted Development elsewhere. Check the guidelines that refer to designated land to ensure you comply with the requirements. 


Eaves and Roof Pitch

Extensions under Permitted Development must ensure that any alteration to the roof pitch matches the existing house, and eaves heights are within specified limits to maintain the visual integrity of the property.

03 Scope of Permitted Development for House Extensions

Understanding the Limitations and Conditions of Permitted Development


Key Limitations


Size and Scale

Permitted Development rights impose strict limits on the size and scale of extensions. For instance, extensions must not cover more than half the garden area, and specific height and length restrictions apply. These limitations are in place to prevent overdevelopment and ensure that extensions are proportionate to the original dwelling.


Design and Appearance

Materials used in extensions should be similar in appearance to those of the existing house, ensuring that the extension blends seamlessly with the original structure. This condition aims to maintain aesthetic cohesion within the local area.



Certain areas, including conservation areas, National Park, Areas of Outstanding Natural Beauty, and the Broads, have more restrictive Permitted Development rights. In these locations, the goal is to protect the distinctive character and beauty of the environment.


Protected Buildings

Listed buildings and properties within designated areas may not benefit from Permitted Development rights or may have severely restricted rights, necessitating specific planning permissions to protect historical and architectural significance.


Conditional Aspects


Prior Notification

For some types of extensions, such as larger single-storey rear extensions, homeowners are required to notify the local planning authority through a process known as ‘prior approval’. This prior approval application allows the authority to consider the impact on neighbours and the immediate environment.


Neighbour Consultation Scheme

This scheme is part of the prior notification process, where neighbours are informed of proposed developments. They have a specified period to raise any objections, which the local authority will consider when deciding whether to allow the development to proceed under Permitted Development rights.


Party Wall Act

When carrying out works to a property that is semi-detached or terraced, it is likely the works are near a party wall. The Party Wall Act imposes a requirement that all adjoining owners be given prior notice of works. In addition, the Party Wall Act provides for a mandatory dispute resolution procedure mediated by an appointed Party Wall Surveyor if the adjoining owners have concerns.


Building Regulations

Even if an extension meets the criteria for Permitted Development, it must still comply with Building Regulations. These cover structural integrity, fire safety, insulation, and other aspects to ensure that buildings are safe and energy-efficient.

04 Understanding the Limitations and Conditions of Permitted Development

Frequently Asked Questions about Permitted Development

Permitted Development rights can often be misunderstood, leading to confusion and potentially costly mistakes. Here are some of the most common questions, along with clarifications to help explain these aspects.


Does Permitted Development Apply Universally?

While Permitted Development rights offer a degree of flexibility, they don’t apply universally across all properties in the UK. Restrictions exist in designated areas such as conservation areas, National Parks, and for listed buildings. Always check with the local planning authority to confirm whether PD rights apply to your property.


Are all Extensions are Covered by Permitted Development?

Not all extensions are covered under Permitted Development. The rights have specific limitations regarding size, height, and location on the property. For example, a two-storey rear extension might not be permissible under Permitted Development in the same way a single-storey extension is. Understanding the detailed criteria is crucial.


Does Permitted Development Eliminate the Need for Approval?

While Permitted Development rights mean that a full planning application is not required, this does not negate the need for lawful development certificates or compliance with other regulatory requirements, such as building regulations. Obtaining a Lawful Development Certificate is advisable to formally confirm that the work is lawful.


Does our Neighbours’ Opinions Matter?

Although Permitted Development rights can reduce the likelihood of neighbour objections through the planning process, this doesn’t mean neighbour considerations are irrelevant. Under the Neighbour Consultation Scheme for larger extensions, neighbours’ feedback can influence the local authority’s decision to allow the development to proceed.


Are Building Regulations Required for Permitted Development Projects?

Even if your project falls under Permitted Development, it must still comply with Building Regulations. These regulations cover structural integrity, fire safety, insulation, and more, ensuring that all construction work meets safety and performance standards.


Do All Areas of the UK have the same Permitted Development rights?

England, Scotland, Wales and Northern Ireland have different requirements under Permitted Development. Our guidance is based on English Permitted Development Rights. For other regions in the UK we recommend consulting with your local planning department. 


Do you need to contact your local authority before carrying out the work under permitted development?

Yes, it is advisable to obtain a Lawful Development Certificate before proceeding with the building work. You also need to ensure you comply with the Building Regulations.

05 Frequently Asked Questions about Permitted Development


Navigating Permitted Development for extension projects can be tricky but it does present a unique opportunity for homeowners and architects. By understanding the framework of rules, limitations, and common misconceptions, you’re better equipped to leverage these rights to their full potential. Remember, every project is different, and the applicability of Permitted Development rights can vary widely depending on location, property type, and specific project details.

The Planning Portal has plenty of useful advice regarding the different types of planning applications, permitted development and planning permission.


Written by Emma Walshaw, Architectural Technologist and founder of First In Architecture and Detail Library. Emma has written a number of books about construction and architectural detailing.

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