Two storey rear extensions are considered to be permitted development, meaning they do not require an application for planning permission provided certain limits and conditions are met. If these limits are exceeded then you will need to apply for planning permission from the local planning authority.

Houses on designated land such as national parks or conservation areas are excluded from the permitted development rights and will require an application for planning permission.

To fall within permitted development rights, the extension should be no higher than the existing house, and where it is within two metres of a boundary, the eaves should be no higher than three metres. 

Any double storey extension to the side or front of the house will require planning permission. You can view the full limits and conditions on our Two-storey extension Mini Guide.

If you live in a listed building you will require listed building consent for any major works to the property.

The failure to obtain planning permission or comply with the details of a permission is commonly known as a 'planning breach'.

A planning breach usually occurs when:

• A development that requires planning permission is undertaken without the permission being granted - either because the planning application was refused or was never applied for
• A development that has been given permission subject to conditions breaks one or more of those conditions.

If the breach involves a previously rejected development (or the retrospective application fails) the council can issue an enforcement notice requiring you to put things back as they were.

There are statutory time limits for enforcement, these vary based on when the breach took place.

If the breach took place prior to 25 April 2024

• Change of use of a building, or part of a building, to use as a single dwelling house - Enforcement action can no longer be taken once the unauthorised use has continued for four years without any enforcement action being taken
• Operational development relating to building, engineering or mining - Enforcement action can no longer be taken from four years, beginning the date where the operations were substantially completed.

If the breach took place on or after 25 April 2024

• Change of use of a building, or part of a building, to use as a single dwelling house - Enforcement action can no longer be taken once the unauthorised use has continued for ten years without any enforcement action being taken
• Operational development relating to building, engineering or mining - Enforcement action can no longer be taken from ten years, beginning the date where the operations were substantially completed.

Other time limits:

There is no time limit for enforcement on breaches of planning control relating to relevant demolition.

For any other breach of planning control, ten years beginning with the date of the breach. This predominantly applies to changes of use.

Read more about breaches of planning control and lawful development certificates on Planning Portal.

Research indicates that more than half of the population would like to build their own home at some point in their lives. While it is a significant commitment that demands time and dedication, the reward is a home designed specifically to suit your needs and lifestyle.

As part of the self-build journey you will have to consider many factors including:

• Finance

• Location and acquiring land

• Modular homes

• Planning permission.

Read detailed guidance about self-build homes on Planning Portal

A shed is classed as an outbuilding which falls under permitted development rights, meaning that it does not require an application for planning permission. They can be built in conservation areas provided they meet the limits set out in legislation.

Specifically on protected land, including conservation areas, no part of the outbuilding can be on the side or front elevation of the house.

A full list of limits and conditions can be read on our outbuildings common project.

Read the outbuildings common project guidance.

Planning permission is not normally required to turn two properties into one by knocking through a party wall provided the changes are internal and do not impact the external appearance of the property.

You should check with your local planning authority that they agree, and there are not any previous planning changes or conditions which may have an impact.

Additional permissions may be required depending on the building’s history and their location. If the building is listed, an application for listed building consent will be required before any major changes are made to the dwellings.

The work will have to comply with building regulations, the focus will be on structural work and safety.

‍Read more about how building regulations apply to internal walls.