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Do I need planning permission to add a first-floor extension onto an existing ground floor extension?
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.
Common Questions
You can usually put up new fences, gates or garden walls without planning permission, as long as you stay within permitted height limits. If the structure is adjacent to a highway (including footpaths), it must not exceed one metre in height. For all other boundaries, the maximum permitted height is two metres. Anything taller than these limits will require planning permission.
Planning permission is not required for moving internal walls in a flat.If the building is a listed building, you may require listed building consent.
Removing a load bearing wall will require building control approval as it is altering the structure of the property. You will be required to provide a report from a structural engineer who will provide structural calculations.
Work on internal walls may also affect fire escape routes, ventilation, drainage or electrics. These should be considered during the design process and work should be carried out by a member of the competent person scheme where possible.
Whether you need building regulations approval depends on the type of underfloor heating (UFH) you are installing.
Electric UFH must comply with Part P for electrical safety.This work can be done by a member of the competent persons scheme who can self-certify the work.
Wet UFH must comply with Part L which focuses on the conservation of fuel and power. This will likely require building control approval.
National planning regulations allow certain alterations to be made to a property without requiring planning permission; these are known as permitted development rights. In some cases, local authorities may remove or restrict these rights for specific types of development that would otherwise be allowed. This is achieved through the use of Article 4 Directions, which are intended to protect the character, heritage, and appearance of designated areas.
If your local planning authority has issued an Article 4 Direction, some of your permitted development rights may no longer apply. As a result, you may need to submit a planning application for works that would not normally require one.
You can check whether an Article 4 Direction affects your property by visiting your local authority’s website.
In most cases, yes - planning permission is required to operate a business from your garage. This is because the use would no longer be purely domestic, and the garage would be considered to have changed use from residential (Class C3) to a business-related use, which requires planning consent.
