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Permitted Development Rights: A Complete Guide

What are Permitted Development Rights?

Permitted Development Rights allow homeowners to extend or modify their properties without applying for full planning permission. The UK government established these rights to facilitate home improvements while maintaining control over developments that might negatively affect neighbouring properties or the environment.

An essential term in this process is the “original dwelling house.” This refers to the house as it stood on 1 July 1948 or when it was first built if constructed later.

Although planning permission may not be required, homeowners must still comply with other regulations, such as Building Regulations, Build Over Agreements, and the Party Wall Act 1996. At Advance Architecture, our team simplifies this process, ensuring smooth project execution.

When do Permitted Development Rights not apply?

Some properties and areas fall outside these rights due to their historical or environmental significance. Restrictions apply to:

• Conservation Areas, National Parks, World Heritage Sites, and Areas of Outstanding Natural Beauty
• Listed buildings
• Flats, maisonettes, and properties converted under permitted development
• Locations under an Article 4 Direction, where local authorities restrict development rights
• Properties with conditions attached to previous planning permissions

What Can You Build Under Permitted Development Rights?

Class A – Extensions, Improvements and other alterations

Single Storey Rear Extension

Homeowners can build single-storey rear extensions if they follow these regulations:

• Must be at the rear of the house
• Materials should match the existing property
• Can extend up to 3 meters for a terraced house or 4 meters for a detached house
• Should not exceed 4 meters in height or 3 meters if within 2 meters of a boundary
• Cannot cover more than 50% of the land around the original dwelling

Single Storey Side Extension

Side extensions follow similar regulations:

• Should be positioned to the side of the house, away from highways
• Must not exceed half the width of the original house
• Materials should match the existing property
• Height should not exceed 4 meters, or 3 meters if within 2 meters of a boundary
• Cannot cover more than 50% of the land around the original dwelling

Wraparound Extensions

Wraparound extensions combine side and rear extensions. These often exceed permitted development limits and require full planning permission.

Two-Storey Rear Extension

For a two-storey extension to qualify under permitted development, it must:

• Extend a maximum of 3 meters on both floors
• Be at least 7 meters from the rear boundary
• Use materials that match the original house
• Not exceed 50% of the width of the original dwelling
• Include non-opening, obscured glass for side-facing upper-floor windows

Replace Windows and Doors

It is typically permitted to replace windows and/or doors without obtaining planning permission. However, the alteration should ensure that the buildings insulation is maintained or enhanced in the changes made, and that the styles and materials used match that of the existing building.

Class B – Loft Conversion

A loft conversion will usually be permitted under the following guidelines

• The extensions should not exceed beyond the plane of the existing roof slope of the principle elevation that fronts the highway.
• Must not exceed 40 cubic metres for terraced houses and 50 cubic metres for detached and semi-detached houses.
• Materials used in the extension should match that of the existing property
• It should not extend up beyond the highest point of the existing roof
• No verandas, balconies or raised platforms are permitted
• Any side-facing windows must have non-openable and obscured glass (unless the openable part if more than 1.7 metres above the floor)
• Roof extensions, apart from hip to gables ones, to be set back at least 20cn from the original eaves.

 Class C – New Roof Lights or any other alterations to the roof:

New roof lights will be permitted under the following guidelines

• The alterations does not protrude more than 15 centimetres (20 centimetres for solar panels) beyond the original roof plane
• It should not extend up beyond the highest point of the existing roof

New chimney, flue or soil and vent pipe will be permitted under the following guidelines:

• Must not be 1 metre of higher than the roof
• Must not be on a wall or roof slope which fronts a highway or is the main elevation of the house.

 Class D – Porches

A porch will be permitted under the following guidelines:

• Must have a maximum footprint of 3 square metres
• Must not be more than 3 metres in height
• Must be set back at least 2 metres from the boundaries of your property and from the road

 Class E – Outbuilding

Outbuildings will be permitted under the following guidelines:

• No outbuilding should be constructed on land fronting the principle elevation
• Outbuildings and garages should be built to a height of no more than 2.5 metres at the eaves and a maximum of 4m if dual pitched. The maximum height of any other roof type proposed should be 3 metres.
• When within 2 metre of a shared boundary, the maximum height of the outbuilding should be 2.5 metres.
• No verandas, balconies or raised platforms are permitted, if raised platforms are over 30cm in height from the existing ground level planning permission is required.
• No more than 50% of the land surrounding the dwelling should be covered by outbuildings.
• If you exceed 30 square metres, you will require Building Control sign off.

Class AA – Building Additional Storeys

Outbuildings

What types of works you can’t do under permitted development rights?

Certificate of Lawfulness:

Your local planning authority can issue you a legal document that is called a certificate of lawfulness. This document confirms that your proposed development falls within the permitted development rights and that you can carry out specific building alterations without the need for planning permission.

Although you do not need a lawful development planning consent to express your permitted development rights, you may want to apply for it as a reassurance that your development will not require planning permission in the future. It is also beneficial to gain this consent if you are planning to sell your property, as it validates to potential buyers that your development is legal.

 What is Prior Approval: Larger Home Extensions?

Prior Approval: Larger Home Extension allows homeowners to build larger house extensions under permitted development rights. This process entails notifying your local planning author about your proposed extension. They then consult with your neighbours, giving them the opportunity to voice any concerns they may have. If there are objections, the local authority may decline prior approval, requiring to seek for full planning permission.

To be eligible to go down the Prior Approval route your proposed extension must meet the following criteria:

• The extension must not extend past the rear wall of the existing house by up to 6 meters for a terraced house or by up to 8 metres for detached houses.
• The extension should be single storey
• Materials used in the extension should match that of the existing property.
• It should not occupy more that 50% of the land around the original dwelling, excluding the area of the original house itself.
• If the extension extends beyond the side of your house, it must be no more than half the width of the existing house.
• It should be less than 4 metres in height as measured from the highest point from the natural surface ground.
• When within the 2 metre boundary of the house, the maximum height of the eaves should be less than 3 metres in height

At Advance Architecture, we specialize in navigating these regulations. Contact us for a free consultation to ensure your home improvement project is legally compliant and well-executed.