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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
Demolishing a building may require planning permission or prior approval, depending on factors such as the building’s type, size, and location.
Before starting any demolition work, it’s important to consult your local planning authority to confirm what permissions are needed. This helps avoid the risk of enforcement action or legal consequences.
You will also need to ensure you conform to the building regulations around the demolishing of a building.
When you, or an agent acting on your behalf, have submitted a planning application, the local authority will firstly check the application to check if it’s complete. This validation process allows the authority to ensure everything that is required to decide an application has been received and provided correctly. They will contact you if they require any further information from you.
After the application has been validated, the determination process begins and takes up to 8 weeks for smaller applications, or up to 13 weeks for larger applications. The authority should be able to give you an idea about the likely timetable. The local authority will contact you with their decision.
Read more about the decision-making process for planning applications.
Most garden ponds will fall under permitted development rights, meaning an application for planning permission is not required. In planning terms a pond will be classed as an outbuilding, to read the full rules around installing an outbuilding, visit our common projects section.
For ponds which are particularly deep or large, you may need to apply for planning permission. If you are unsure, you should contact your local planning authority for advice.
In a listed building you will require listed building consent for any major changes.
When installing a pond, you should take into account other regulatory considerations such as environmental permits or any protected species which may be impacted. Further thought will have to be placed when creating ponds near riverways or in areas of flood risk.
Installing solar panels on your roof will often fall under permitted development rights, meaning an application for planning permission is not required provided certain limits and conditions are met.
The limits and conditions vary based on the type of roof you want to install the solar panels on and the location of the house. See the details below:
· On a pitched roof, panels should not be installed above the highest part of the roof (excluding the chimney) and should project no more than 200mm from the roof slope or wall surface.
· On a flat roof the highest part of the solar PV equipment cannot be more than 600mm higher than the highest part of the roof(excluding chimney).
· The panels must not be installed on a building that is within the grounds of a listed building or on a site designated as a scheduled monument.
· If your property is in a conservation area, or in a World Heritage Site, panels must not be fitted to a wall which fronts a highway.
As you have stated you’re in a conservation area, you must apply to the local authority for prior approval. This process includes submitting a form to the local planning authority which ensures that you meet the limits set out in legislation.
Forms relating to prior approval for mounting solar equipment can be submitted through the Planning Portal’s online application service and attract a fee of £240.
Visit our solar common projects page for more details and to explore similar permissions.
The conversion of a garage, or part of a garage, into habitable space, will normally require approval under the building regulations.
As part of the garage conversion, it is likely that the original garage door will be in-filled with a new wall and possibly a window or door, and a new foundation may be needed for the new wall.
As well as the foundation, you also need to consider:
- Floor
- Walls
- Ventilation
Read more about the building regulations for garage conversions.
