Adding a porch canopy is classed as permitted development provided it meets the limits and conditions set out in legislation. Where this is the case, no application for planning permission is required.

Porches must meet the following limits:

• the ground floor area (measured externally) would not exceed three square metres.
• no part would be more than three metres aboveground level (height needs to be measured in the same way as for a house extension).
• no part of the porch would be within two metres of any boundary of the dwellinghouse and the highway.

Read our mini guide for additional information on installing a porch.

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Planning permission is unlikely to be required for the installation of external damp proofing unless the work will change the external appearance of the building or is part of a larger project.

If you live in a listed building you will need listed building consent for any significant changes, this can include external damp proofing. Additional rules may also apply if you live in a Conservation Area or other protected area.

Building regulations approval is not required for installing an external damp proof course (DPC).

Read further guidance on damp proofing.

Adding a storey on top of an extension will always require an application for planning permission.

If you want to add a storey on top of your house under permitted development rights, it must be on the principal part of the house.

If you want to add an additional storey on top of your house, it can be permitted development. It is only permitted development if it follows certain rules:

The current house

• Is not a building containing one or more flats, or a flat contained within such a building
• Was constructed between 1 July 1948 and 28 October 2018
• Has not already had additional storeys added to it
• Is not on Article 2(3) land or a site of special scientific interest
• Was not changed to be used as a house (from a previous non-residential use) under permitted development rights.

How many storeys can you add?

• If the house is one storey then one storey can be added
• If the house is two or more storeys then two storeys can be added

Where can the storeys be added?

• The additional storeys must be added to the principal part of the house. The principal part of the house is the main part of the house excluding any front, side or rear extension of a lower height (regardless of these being part of the original house or subsequent additions).
• Engineering operations must only include works within the existing curtilage of the house to strengthen existing walls and foundations

How high can it be?

• The house cannot exceed 18 metres in total height
• Each storey cannot add more than 3.5 metres to the total height
• If the house is not detached the total height cannot be more than 3.5 metres higher than the next highest building that the house is attached to, adjoins, or is in the same row as.
• The additional storeys must have an internal floor-to-ceiling height of no more than 3 metres, and no greater than the internal height of any existing storey within the principal part of the house.

What materials can be used?

The materials used must be of a similar appearance to those used in the construction of the exterior of the current house

Where can windows be placed?

Windows must not be placed in any wall or roof slope forming a side elevation of the house.

Following completion of development:

• The house must remain in use as a domestic residential property
• No visible support structures must remain on or attached to the exterior of the house
• The roof pitch of the principal part of the house must be the same as it was prior to the development.

 If any of the limits set out above are exceeded then an application for planning permission will be required. If you are unsure, you should contact your local planning authority.

Find contact details for your local planning authority.

If you're doing electrical installation work in your home or garden in England or Wales, you must follow the building regulations. It's recommended to hire an installer who is registered with a competent person scheme (a registered competent person’) who can self-certify that the work meets the required standards.

An application for full planning permission for a change of use is often required when changing from a house (use class C3) to a residential institution (use class C2). This is due to the increased activity which a C2 use would have on the local street area through the addition of visitors, staff and changes to parking.

Read additional information on use classes and changes of use.

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