Do I Need Planning Permission? 5 Projects Where the Answer Could Be “No!”

Some home improvements don’t need permission.

“Do I need planning permission?” If you want to renovate or extend your home or garden, this might be one of the first things you ask yourself. 

And often, the answer depends on the type and size of the project you’re planning. Major renovations can grind to a halt when faced with local planning regulations, causing delays and additional expenses. So, it pays to know where you stand when it comes to planning permission. 

However, under something called “permitted development,” there are several common home improvement projects that you can tackle without planning permission. We’ve listed them below. 

But first, let’s explore planning permission in a little more detail — including why you might need it and what it involves.  

What is planning permission?

In simple terms, planning permission is consent from your local authority to build something new or make alterations to an existing structure. It’s a legal process put in place to prevent inappropriate or dangerous developments from taking place.  

How do you know if you need planning permission in the UK?

According to, permission is required if the work being carried out can be defined as a “development” under section 55 of the Town and Country Planning Act 1990.

In broad terms, “development” includes:

  • Major structural changes to a building
  • Construction, rebuilding, or demolition
  • Material changes to the use of land or buildings (from a residential property to a hotel, for example)
  • Engineering operations, such as groundworks
  • The subdivision of residential property from one home to two or more separate homes

To find out if your project needs permission, contact your local planning authority via your local council

What do I need for planning permission?

The process of applying for planning permission can vary from one local authority to another. 

However, in general, you’ll need the following:

  • Your name and address
  • A postal address of the land you’re developing (if different from your own)
  • A description of the development
  • A certificate of ownership 
  • Any other plans and drawings needed to describe the proposed development

How much does planning permission cost?

Planning permission costs depend on the type of development you’re planning and where in the UK you’re based. 

According to Checkatrade, a full planning permission application in England costs £462, while in Wales, it’s £460, and in Scotland, it’s £600.

Meanwhile, permission for alterations or extensions ranges from £206 in England to £230 in Wales and £300 in Scotland.

So, what can you put up without planning permission? 5 home improvement projects you can tackle under permitted development.

Permitted development is granted by the UK government to allow certain building works to be carried out without planning permission. 

Permitted development rights are subject to national conditions and limitations (for example, limits on size, height, or location). However, these rights can be removed by local planning authorities, meaning a project that wouldn’t usually require permission in one area will require approval in another.

Heads up: While the projects below generally won’t require planning permission, you should always get advice from your local council, architect, or builder to make sure your plans are within the rules.

If your home is a listed building or you live in a conservation area, you may need to make a planning application before you can renovate. And if a previous owner has already extended your property, it may have used up its permitted development allocation, meaning you can no longer make any alterations without planning permission.

1. Do I need planning permission for an extension?

Not always! Many home extensions can fall under permitted development if they meet specific criteria. 

  • New extensions must be built using the same (or similar) materials as the existing property.
  • If you have a detached property, you can extend it by up to 8m to the rear with a single-storey extension or 3m with a double-storey extension.
  • If you live in a semi-detached or terraced house, you can extend by up to 6m to the rear.
  • If you want to extend to the side of your home, you can only build a single-storey extension with a maximum height of 4m. It cannot be more than half the width of the original building.
  • Single-storey extensions cannot be higher than 4m on the ridge and the eaves. The ridge height cannot be higher than the existing property.
  • Extensions cannot cover more than half of the garden. 

2. Do I need planning permission for a conservatory?

Like an extension, many conservatories can be built without planning permission —  as long as they don’t exceed specific dimensions.

A conservatory should not cover more than half of the land around a home and cannot be higher than the highest roof. If your property is single-storey (such as a bungalow), you can still add a conservatory as a permitted development, but it cannot be higher than 4m.   

3. Do I need planning permission for a garage conversion? 

During the last few years, garage conversions have become popular as many people seek to improve their homes instead of moving. Whether it’s an extra bedroom, a games room, a gym, or an office, converting unused (and unloved) garage space can add a massive amount of practicality and value to your home. But do you need planning permission to convert a garage?

Often, the answer’s a simple “no!” A garage conversion will likely fall under permitted development, with only a few exceptions requiring planning permission. 

For example, if the garage is detached from your house, you may need to go through the planning process, as you’ll be changing its use as a standalone building. 

And if the garage was built after the house, you should check with your local planning authority before making any changes. Adding a garage to the property could have used up your home’s permitted development allocation.

4. Do I need planning permission for a shed or garden office?

If you don’t have a garage to convert, adding a shed or garden office to your home could be a great way to create some much-needed workspace. And as long as you meet certain conditions, you can build an outbuilding on your property without planning permission. 

  • Outbuildings like sheds, summerhouses, or garden offices can be built under permitted development, provided they don’t exceed 50% of the total area around the property.
  • Height restrictions also apply. They must be single-storey, with a maximum eaves height of 2.5m.
  • And outbuildings built under permitted development cannot be used for residential accommodation. 

5. Do I need planning permission for new windows or doors? 

No, you won’t usually need planning permission to add new windows or doors to your home. This is also true if you want to replace windows or if you want to change a window into a door (for example, adding French doors to the rear of your property). 

However, if your home is a listed building, you’ll need to maintain your home’s original features — and this can limit the changes you can make. If you need to replace a faulty or damaged window, you’ll probably only be able to make a like-for-like swap rather than introducing a new window style.

To recap: What size can you go to without planning permission?

If you’re planning to extend your home, you can usually do so without permission as long as the extension doesn’t exceed specific dimensions. For detached properties, that’s 8m to the rear of the property, or 6m for semi-detached and terraced houses. And most extensions or additions to your property (such as outbuildings) cannot cover more than half of your garden. 

Finally, remember that even if you believe your project falls under permitted development, it’s always a good idea to double-check. If you build something that is later found to have been outside permitted development, you could be on the hook for a hefty fine — and may even need to demolish it if you can’t get retrospective planning permission. 

Also read:
Where to start with a house extension? 
What is a party wall agreement? 
Listed Buildings: Here’s what you need to know