Planning permission for altering your house

If you are going to build an extension or make other changes to your house, you may need planning permission from your local authority.

The most common reasons for needing planning permission are when you want to:

• Build an extension which is more than 40 square metres (this includes new and any existing extensions)
• Change how your land is used, like converting a garage to a place of business. This is known as a “material change of use”.

Generally, you do not need planning permission for minor changes to your house. See ‘What changes can I make without planning permission’ below.

However, you should check if you need planning permission before you start building. If you do not get planning permission when it is needed, you may have to pay a large fine or even face going to prison. Your local authority can advise you if you have questions.

For more information on applying for planning permission and the different types of planning permission, see our page on Planning permission.

Generally, you will not need planning permission for the following changes to your home.

Extensions smaller than 40 square metres

You can build an extension or conservatory to the rear of your house as long as it:

• Does not increase the original floor area of the house by more than 40 square metres
• Is not higher than the house

An extension above ground level must be at least 2 metres away from any boundary and the floor area must not exceed:

• 12 square metres for terraced or semi-detached houses
• 20 square metres for detached houses

Under these rules, the total floor area is:

• The floor area of the extension you are now proposing, and
• The floor area of any previous extensions including those you previously got planning permission for

Also, the extension must not reduce the open space at the back of the house (that is used only by the people who live in the house) to less than 25 square metres.

There are also detailed rules about:

• The height of an extension
• Where the windows are placed in an extension
• How the roof is used

Garages and sheds

You can convert a garage attached to the back or side of your house to domestic use as long as it has a floor area of less than 40 square metres. If you want to convert a garage for business use, see ‘Planning permission for a material change of use' below.

You can build a garage, shed, greenhouse or similar structure at the back or side of your house as long as it:

• Does not extend out in front of the building line of the house
• Is 4 metres or lower in height if it has a tiled or slated pitched roof, or 3 metres in height if it has any other roof type

You do not need planning permission for this type of garage or shed as long as the floor area on its own or together with any similar structures isn't more than 25 square metres.

The new garage or shed should not reduce the open space at the back or side of the house to less than 25 square metres.

Garages or sheds to the side of the house must match the finish of the house.

There are certain rules you must follow when building a garage or shed. They must not be:

• Lived in
• Used for commercial purposes
• Used for keeping pigs, poultry, pigeons, ponies or horses

Front porches

You can build a front porch without getting planning permission as long as it:

• Is not more than 2 square metres in area
• Is more than 2 metres from any public road or footpath

If the porch has a tiled or slated pitched roof, it must not be higher than 4 metres, or 3 metres for any other type of roof.

Capped walls, wooden fences, gates and access

You can build capped walls (made of brick, stone or block), railings and wooden fences up to 1.2 metres in height at the front of the house, or 2 metres at the side or back of the house. This includes security fences.

You can build gates up to 2 metres high.

You always need planning permission if you want to widen or create new access to a public road.

Central heating systems

You can install a central heating system, chimney, boiler house or oil storage tank (up to 3,500 litres capacity).

Gardens and yards

You can alter your garden or yard to include car parking spaces, garden paths, ponds and other items, as long as the changes are not more than one metre above or below ground level.

Objects on the roof of the house

You can install:

• A TV aerial on the roof so long as it is less than 6 metres above the roof
• A satellite dish at the back or side of the house up to one metre in diameter, and not higher than the top of the roof

You must get full planning permission for a satellite dish on the front of the house. You must only install one satellite dish on your house.

Wind turbines and solar panels

You can install a wind turbine for domestic use as long as:

• It is not attached to a structure
• It is not more than 13 metres high
• It has a rotor diameter of less than 6 metres
• There is a clearance of at least 3 metres between the tip of the rotor and the ground

You do not need to get planning permission to fit solar panels to the roof of your house. You can cover your whole roof with solar panels without needing planning permission.

You can install freestanding solar panels at your house without needing planning permission as long as:

• They are not in front of the house's front wall
• They are less than 2.5 metres above ground
• They don’t cover more than 25 square metres
• The private open space to the rear or side of the house is not reduced to less than 25 square metres

There are certain restrictions if your home is a protected structure or in an architectural conservation area. Additional restrictions may also apply if glare from your solar panels will be an issue. It is important to check with your local authority for full details before making any changes to your house.

You can find more information in A Guide to Doing Work around the House (pdf) published by the Office of the Planning Regulator. Other publications available include A Guide to Planning Permission (pdf) and A Guide to Making a Planning Application (pdf).

If you want to make a “material change” to how you use your land or buildings, you will need planning permission. A material change means a significant change that will have an impact on your neighbours or your local community.

For example, you will need planning permission if you want to:

• Convert your garage into a workshop for business use
• Open a crèche
• Open a bed and breakfast with more than 4 guest bedrooms

You may also need to get planning permission if you are renting your property for short-term lets.

There are some exceptions to the requirement for planning permission for a material change of use. For example, you do not need planning permission to change certain vacant commercial properties (including pubs) into homes.

These exceptions are set-out in the Planning and Development Regulations 2001 to 2023 (pdf).

Contact your local authority if you need to apply for planning permission, or you are not sure if you need planning permission.