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Permitted Development – intro
Permitted Development
Not every home improvement project needs a full planning application.
In many cases, homeowners can extend or alter their property using Permitted Development rights.
These rights allow certain types of building work to go ahead without applying for standard planning permission, provided the proposal stays within specific limits and conditions.
For the right project, this can make the planning stage much simpler.
But Permitted Development is not simply a case of keeping an extension below a certain size.
The rules can depend on the type of property, the position of the work, its height, materials, previous extensions and whether additional restrictions apply to the site.
At Tholos, we help you understand whether Permitted Development is the right route for your project and develop the design accordingly.
Permitted Development
What Is Permitted Development?
Permitted Development rights are planning permissions granted automatically by national legislation.
They allow certain types of work to be carried out without submitting a standard planning application to the local authority.
For homeowners, this can include some:
- single-storey rear extensions
- side extensions
- loft conversions
- dormers
- roof alterations
- porches
- outbuildings
- changes to windows and doors
The important word is some.
Each type of development has its own rules, and the proposal needs to meet all the relevant conditions to qualify.
Is Permitted Development the Same Everywhere?
Not always.
Permitted Development rights are subject to national rules, but individual properties can have additional restrictions.
Your rights may be different if the property is:
- in a conservation area
- a listed building
- located within another designated area
- subject to an Article 4 Direction
- a flat or maisonette rather than a house
- affected by conditions attached to an earlier planning permission
Previous work to the property can also matter.
For example, earlier extensions may have already used part of the allowance available under Permitted Development.
This is why the property itself should be checked before assuming a project qualifies.
Permitted Development
Permitted Development for Rear Extensions
Single-storey rear extensions are one of the most common uses of Permitted Development rights.
Depending on the property and the proposed design, you may be able to extend from the original rear wall without making a standard householder planning application.
The rules can consider several factors, including:
- how far the extension projects
- its overall height
- the height of the eaves
- proximity to boundaries
- materials
- how much land around the original house is being developed
These restrictions need to be considered together.
An extension might meet the projection limit but fail another condition relating to height or position.
The design therefore needs to respond to the entire set of rules.
Permitted Development
What Does “Original House” Mean?
This is an important part of Permitted Development that can catch homeowners out.
The rules often refer to the original house, which generally means the property as it stood on 1 July 1948, or when it was first built if it was constructed after that date.
It does not simply mean the house as it looks today.
If a previous owner has already added an extension, that addition may count when determining how much further development is permitted.
This means buying a house with an existing extension does not necessarily give you a fresh Permitted Development allowance.
Understanding the history of the property can therefore be important before deciding how large a new extension can be.
The local authority will normally notify adjoining neighbours and assess particular impacts, especially how the proposal might affect neighbouring amenity.
This is not quite the same as standard planning permission.
However, it is also not an automatic right to build whatever size extension you want.
The proposal still needs to comply with the relevant requirements.
Permitted Development
Larger Home Extensions
Some larger rear extensions may be possible through the Prior Approval process rather than a standard planning application.
This route allows certain larger single-storey rear extensions to be considered under a specific Permitted Development procedure.
The local authority will normally notify adjoining neighbours and assess particular impacts, especially how the proposal might affect neighbouring amenity.
This is not quite the same as standard planning permission.
However, it is also not an automatic right to build whatever size extension you want.
The proposal still needs to comply with the relevant requirements.
Permitted Development
Permitted Development for Side Extensions
Side extensions can also fall within Permitted Development rights, but the restrictions are generally tighter than for some rear extensions.
The proposal may be limited by factors such as:
- height
- width relative to the original house
- whether the extension has more than one storey
- proximity to boundaries
- whether the property sits on designated land
Two-storey side extensions will usually require a planning application.
Even where a single-storey side extension could be Permitted Development, it is still worth considering whether those limits create the best design for the property.
Permitted Development
Permitted Development for Loft Conversions
Many loft conversions can be completed under Permitted Development rights.
The rules typically consider the additional roof volume being created and where that new volume is positioned.
Depending on the property, Permitted Development may allow:
- rear dormers
- some roof extensions
- rooflights
- alterations to accommodate the conversion
There are limits on the amount of additional roof space that can be created, and restrictions commonly apply to alterations facing the principal elevation.
Materials and the position of balconies or raised platforms can also affect whether the work qualifies.
Even where planning permission is not required, the loft conversion will normally still need Building Regulations approval.
Permitted Development
Permitted Development Does Not Mean “No Rules”
This is probably the biggest misconception around Permitted Development.
It removes the need for a standard planning application in qualifying cases, but it does not remove the need to comply with other requirements.
Your project may still require:
- Building Regulations approval
- structural design
- Party Wall procedures
- drainage agreements
- technical drawings
- compliance with restrictive covenants
There may also be specific conditions attached to the Permitted Development rules themselves.
So while the planning process can be simpler, the project still needs to be properly designed and prepared for construction.
Permitted Development
Planning Permission or Permitted Development?
Permitted Development can be useful, but staying within it should not automatically become the main objective of the design.
Sometimes the Permitted Development limits work perfectly for what you need.
Sometimes they do not.
Imagine the ideal extension for your home projects slightly further into the garden than the Permitted Development allowance.
Reducing it purely to avoid a planning application may leave you with a noticeably poorer layout.
In that situation, making a planning application could be the better route.
The question should be:
What is the best project for the house and the people living in it?
Once that is understood, you can decide whether Permitted Development or planning permission provides the most appropriate way to achieve it.
Permitted Development
What Is a Lawful Development Certificate?
Even when your project falls within Permitted Development rights, it can be sensible to obtain formal confirmation that the work is lawful.
This can be done through an application for a Lawful Development Certificate.
The certificate provides evidence from the local authority that the proposed work did not require a standard planning application at the time it was assessed.
For many homeowners, this provides useful certainty before construction starts.
It can also be valuable later if you sell the property and need to demonstrate that the extension or alteration was carried out lawfully.
Do You Have to Apply for a Lawful Development Certificate?
Not necessarily.
Where work clearly falls within Permitted Development rights, a Lawful Development Certificate is not always legally required.
However, having written confirmation can remove uncertainty.
That can be particularly worthwhile for substantial projects such as extensions and loft conversions where a significant amount of money is about to be invested.
It also gives you a formal record rather than relying on your own interpretation of the planning rules.
Permitted Development
Drawings for a Lawful Development Certificate
A Lawful Development Certificate application normally needs enough information for the council to determine whether the proposal meets the relevant Permitted Development rules.
Depending on the project, this may include:
- existing floor plans
- proposed floor plans
- existing elevations
- proposed elevations
- site and location plans
- dimensions showing the size and position of the work
Accuracy matters.
The decision is based on whether the development shown on the drawings meets the relevant legal requirements.
If the construction later differs materially from the approved drawings, that certificate may no longer provide the certainty you expected.
Permitted Development
Permitted Development and Building Regulations
Permitted Development deals with planning.
Building Regulations deal with construction.
They are completely separate.
An extension may be fully permitted under planning legislation but still require Building Regulations approval for areas such as:
- foundations
- structure
- insulation
- fire safety
- ventilation
- drainage
- glazing
You therefore still need to develop the project technically before your builder starts work.
Permitted Development
From Permitted Development to Technical Design
Once the planning position has been established, the project can move into the detailed design stage.
This is where the proposal starts to become something a builder can actually construct.
The technical design may need to resolve:
- wall and roof build-ups
- structural openings
- insulation
- foundations
- drainage
- glazing
- construction junctions
This information goes beyond the drawings used simply to demonstrate that a project qualifies as Permitted Development.
Permitted Development
Structural Design for Permitted Development Projects
An extension does not become structurally simple just because it falls under Permitted Development.
Large openings between the existing house and a new extension can still require significant beams, columns or additional foundations.
Loft conversions may require new floor structures and alterations to the roof.
Structural requirements should therefore be developed alongside the technical drawings before the project goes to tender.
This gives the builder a much clearer understanding of what they are expected to construct.
Permitted Development
Why Resolve Permitted Development Before Finding a Builder?
Speaking to builders early can be useful.
But asking them for final quotations before you know what you are legally allowed to build usually creates unnecessary uncertainty.
A builder can only price the project shown to them.
If the size, layout or planning route later changes, the quotation changes too.
Resolving the design and confirming the planning position first gives you:
- a defined project
- clearer construction drawings
- more comparable quotations
- fewer assumptions
- better control over the tender process
The builder is then pricing the project you actually intend to build rather than an early idea that may still change.
Client experience
"
Lorem ipsum dolor sit amet, consectetur adipiscing elit. We had a vision for our home but no idea how to realise it. Tholos Interiors took complete ownership of the project — every detail was considered, every decision explained. The result exceeded everything we had imagined.
– Lawrence Ipsum, Homeowner · London –
Frequently Asked Questions
Do I need planning permission if my project is Permitted Development?
No standard planning application is normally required if the work fully complies with the relevant Permitted Development rules.
How far can I extend under Permitted Development?
It depends on the property, the type of extension and the specific rules that apply. Different limits can apply to detached and other types of houses, and larger extensions may follow a Prior Approval process.
Can a two-storey extension be Permitted Development?
Some limited forms of additional development may qualify, but two-storey extensions are subject to much stricter rules and many proposals will require planning permission.
Can I build a loft conversion under Permitted Development?
Often, yes. Many loft conversions and rear dormers can qualify, provided they remain within the relevant volume, position and design restrictions.
Do flats have Permitted Development rights for extensions?
The household Permitted Development rights that apply to houses do not generally apply in the same way to flats and maisonettes.
What is a Lawful Development Certificate?
It is formal confirmation from the local authority that the proposed development is lawful under planning legislation.
Do I need Building Regulations if the extension is Permitted Development?
Usually, yes. Permitted Development relates to planning permission, not Building Regulations.
Can previous extensions affect my Permitted Development rights?
Yes. The rules often relate back to the original house, so previous extensions can affect what additional work is permitted.
Can Tholos check whether my project qualifies?
Yes. We can assess the property and proposed work, identify the appropriate planning route and prepare the design and drawings needed to move the project forward.
Not Sure Whether You Need Planning Permission?
You do not need to understand every planning rule before you start designing your project.
Tholos can assess the property, look at what you want to achieve and determine whether Permitted Development, Prior Approval or a planning application is likely to be the most appropriate route.
From there, we can develop the project through planning, Building Regulations, structural design and technical drawings before helping you take it to builders.
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