What is Permitted Development?
- Internal remodelling
- Windows and doors
- Garages and attached buildings
- Single storey extensions
- Loft conversions
- Two storey extensions
- Sheds and outbuildings
- Converting two homes into one
- Gates, walls and fences
- Swimming pools
- Adding vehicular access
- Cladding and exteriors
- Solar panels
- Change of use to residential (school, church, barn, mill etc. conversions)
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1. Internal Remodelling
If what you propose does not require you to extend the overall footprint of the dwelling, Permitted Development (PD) allows you to carry out the work without obtaining full planning permission. You will, however, need to follow Building Regulations guidance for some aspects such as structural elements and electrical works.
2. Moving Windows & Doors
You do not normally need planning permission to replace or add new windows in the original walls of your house. However, you may need planning permission if conditions were attached to the original permission. Double glazing can be installed under PD, providing the building is not listed. For new or bigger windows or doors, you will need to follow Building Regulations guidance.
Bear in mind that bay windows are classed as extensions. Planning permission to insert a new window or door opening is not required as long as any upper floor windows on the side elevation are glazed with obscured glass (level 4 or 5 obscurity). They must also be fixed into a non-opening frame (unless the opener is more than 1.7m above the floor of the room in which the window is installed).
(MORE: Our Guide to Choosing Windows)
3. Using Attached Buildings, e.g. Garages
If you wish to alter the internal space within an existing part of the building, such as incorporating an integral garage, you can do so under PD providing you are not increasing the overall footprint of the dwelling.
4. Single Storey Extensions
You can build various single storey extensions without planning permission, providing the extension accords with the following:
- The extension does not sit forward of the principal elevation.
- Materials should be similar.
- Where it is within 2m of any boundary, the eaves cannot be higher than 3m, and no more than 4m in height otherwise.
- Rear extensions — no more than 4m in depth (detached house) or 3m in depth (semi-detached or terrace).
- Side extensions — the width of the extension must not be greater than half the width of the original dwelling. Side extensions are not permitted on Article 1(5) Land (e.g. AONB, Conservation Areas).
See the planningportal.gov.uk for a full list of caveats.
A stunning light-filled extension has completely transformed the internal dynamic of this London home
Alterations can be made to the roof of a dwelling under PD. However rooflights are not permitted under PD where they would extend forward of the roof plane on the elevation fronting a highway. But they are permitted providing they do not project more than 15cm from the roof slope. Rooflights are not permitted on a dwelling which is located in an Article 4 Direction Area. Two common examples are a Conservation Area or an Area of Outstanding Natural Beauty.
(MORE: Rooflight Buyer’s Guide)
6. Loft Conversions
Loft conversions provide a great opportunity to create additional space and may not require planning permission. Permitted Development allows for the construction of dormer windows, which would provide additional headroom within a converted attic. However, they must not sit higher than the highest part of your existing roof, or extend forward of the roof plane on the principal elevation.
There are also limitations on the cubic content allowed under PD but generally up to 40m³ is fine.
(MORE: Loft Conversion Beginner’s Guide)
7. Two Storey Extensions
A two storey extension can only be built under PD if it is at the rear of the dwelling (this includes the addition of a second storey onto an existing single storey part of the house). In addition, your two storey extension must not exceed 3m in depth or be within 7m of the rear boundary. Specific restrictions also apply to the glazed nature of windows in such extensions.
Conservatories and orangeries fall under the same restrictions as single storey extensions and as they often tend to be fairly modest in size, they can be built without the need for planning. Check the rules about single storey extensions above.
9. Sheds and Outbuildings
Outbuildings are a clever way to add extra space without the need for planning permission
Where you have a larger plot, there may be opportunities to build multiple outbuildings under PD, providing the total area covered by such buildings/enclosures does not exceed 50% of the total area of the curtilage. This 50% should take into account any extensions, but not the area covered by the main house.
Outbuildings cannot sit forward of the principal elevation, and there are height restrictions depending on the type of roof (4m for dual pitch roofs, 3m for other roofs, and 2.5m when the building is within 2m of the boundary). Outbuildings may only be single storey, with the maximum eaves height remaining at 2.5m.
A key factor to bear in mind when considering what you want to achieve from an outbuilding is that the use should be ‘incidental’ to that of the dwelling, e.g. gym, garage, store. Outbuildings under PD cannot be used for residential accommodation, e.g. bedrooms, but can be used to provide a place to work from home.
10. Converting Two Homes Into One
It may also be worth considering the benefits of converting two houses, such as a pair of semis or two flats, into one property. This can usually be done under PD, and would save you moving out of an area you love. However, if you were considering the option of dividing a property into two dwellings, unfortunately the same rules do not apply and you would need to apply for planning permission.
Whilst many of the schemes described so far have not allowed for the development of any extensions forward of the principal elevation, you can build a porch on the front of your property without obtaining planning permission, as long as you follow certain rules:
- No part of the porch can be taller than 3m
- It cannot be within 2m of any boundary adjacent to a highway
- The ground area (measured externally) does not exceed 3m²
Provided they don’t measure more than 3m², porches can be added without needing planning permission. Find out more about this low budget cottage
(MORE: Ten Great Porches)
12. Gates, Walls and Fences
It’s worth knowing that Permitted Development facilitates the erection, construction, maintenance, improvement or alteration to a gate, fence, wall or other means of enclosure, providing such work accords with the following limitations:
- The height would not exceed 1m when adjacent to a highway
- The height would not exceed 2m for any other gate, fence etc
- Such development is not permitted under PD around a listed building
Whilst a raised platform (a platform with a height greater than 300mm) would require planning permission, garden decking and other such similar structures which are of a height below this limit can be built without planning permission, providing they accord with certain criteria (available at planningportal.co.uk).
14. Swimming Pools
When looking to enhance the enjoyment of your garden, what better way than to build a swimming pool for the whole family to enjoy? Under Permitted Development rights you can build a pool within your garden, provided that the total area covered by the pool does not exceed 50% of the area of the garden curtilage.
Swimming pools such as the one in this Californian style home, designed by Hyde+Hyde Architects, can be built under Permitted Development providing they don’t exceed half the garden
15. Some New Accesses Don’t Need Planning Permission
Planning permission is not required when creating a new vehicular access onto an unclassified road. However, permission is needed for accesses onto classified roads. For a new access onto a classified road, you will need to ensure sufficient visibility when leaving the site, as well as enough turning space to allow you to enter and exit in a forward gear.
Cladding (stone, pebble dash, render, timber, etc.) is not permitted under PD on any dwelling house located on Article 1(5) land (in special areas, e.g. an AONB). Yet, on other buildings not affected by an Article 1(5) land, cladding changes may fall under Permitted Development.
(MORE: Guides to Cladding and Render)
17. Solar Panels
Solar panels can also be developed under PD, providing they do not protrude more than 200mm beyond the plane of the wall or roof, and that the highest part of the panel is not higher than the highest part of the roof (excluding the chimney). Limitations apply in Conservation Areas and on listed buildings. Free-standing panels can also be developed, but are limited in size and proximity to the boundary.
(MORE: Our Guide to Buying Solar Panels)
If your property does not provide you with sufficient opportunities to develop extensions to your home above ground, have you ever considered building a basement? This would provide you with extra internal space, without reducing the size of your garden. In a recent appeal decision, it was considered that basements could be PD under Class A of the General Permitted Development Order (GPDO). However, PD does not allow for engineering works.
A semi-basement was built in to this narrow plot home in London
Class F of the GPDO refers to the provision of hard surfaces, such as parking areas. These are also permitted under PD providing that any hard surface situated between the principal elevation of a dwelling and the highway, or any surface which would exceed 5m², is made of porous materials, or provision is made to direct run-off water from the surface into a permeable/porous area within the property curtilage… not onto the highway!
20. Change of Use
It is possible to convert an industrial, commercial or agricultural building for residential use, without the need for planning permission. As is often the case, you will require approval for Listed Buildings and in Conservation Areas. You will also need to follow the Prior Notification procedure if you are converting an agricultural building such as a barn.
What is Prior Notification?
Prior notification came into force in 2013. Under this planning change, single-storey, rear residential extensions can be built up to 8m in depth (6m for a semi or terrace), provided that boundary neighbours are first informed or given ‘prior notification’.
As long as there are no objections, or any objections received have no planning merit, then a Certificate of Lawful Development is issued.
The 2013 changes also allowed for the change of use of buildings from office use (B1) to residential (C3).
Prior Notification Extended to Agricultural Buildings
In April 2014, the scope for prior notification was expanded to include Class Q. This allows for the change of use from agricultural buildings to ‘dwelling houses’, subject to certain conditions. In addition, the agricultural building must be capable of functioning as a dwelling house without serious structural changes (although some operations would be permitted).
An agricultural conversion can result in the creation of no more than three residential units, using up to a maximum of 450m3 of internal floorspace.
A Last Word on Planning Permission
Whilst this article provides a summary of what you may be able to do under Permitted Development, you should always check with the Local Planning Authority to ensure you do not require planning permission, as in some cases PD rights may have been removed. If you’re thinking of selling the property in the future, then it might be best to obtain a Certificate of Lawful Development, confirming the project falls within PD. They are obtainable from your local authority. An application usually costs £75. For more information on PD visit planningportal.gov.uk
It must be noted also that Scotland, Wales and Northern Ireland each benefit from their own version of these rules, so it is always best to check with the relevant planning authority.