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How high can I build a single-storey extension without planning permission?
A single storey rear extension can fall under permitted development, meaning planning permission may not be required providing it meets certain criteria.
In terms of height, the extension must:
- Be no taller than four metres at its highest point
- Have eaves no higher than the eaves of the original house
- Not exceed the height of the original dwelling
Read about planning permission for extensions on Planning Portal
Common Questions
Many homeowners choose to replace their traditional polycarbonate conservatory roof with a solid tiled roof for better thermal efficiency.
If the change significantly alters the structure or appearance of the roof, then planning permission may be required. Most alterations to roofs are considered permitted development, providing they meet the limits set out in legislation.
A new roof must comply with building regulations to ensure it is structurally safe, energy efficient and properly ventilated.
In many circumstances, rules known as ‘permitted development’ rights allow you to extend a house without needing to apply for planning permission, providing specific limitations and conditions are met. If you want to exceed these limits and conditions, then it is likely that an application for householder planning permission will be required.
The limits and conditions for building an extension under permitted development rules are covered in our guidance on the Planning Portal, and there are other points to take into consideration.
Visit Planning Portal to find out more.
In many circumstances, rules known as ‘permitted development’ rights allow you to extend a house without needing to apply for planning permission, providing specific limitations and conditions are met. If you want to exceed these limits and conditions, then it is likely that an application for householder planning permission will be required.
You can find information about the limits and conditions, prior approval and the building regulations on the Planning Portal by using the links below.
Read about planning permission for extensions
Read about prior approval for larger single storey extensions
Find out about building regulations for an extension
A roof window (or skylight) is fitted flush within the slope of a roof, while a dormer projects outward, creating additional headroom and floor space.
Both can be installed under permitted development but must meet specific size and position limits to qualify.
Also consider building regulations for a new dormer, find out more on Planning Portal
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.
