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Home improvements that don't need planning permission

Is your home ready for a refresh? Here are the large projects you can tackle without having to apply to your council for planning permission.

Words by: Nic Hopkirk

Senior Editor

Not every home or garden improvement needs planning permission.

There are plenty of projects that can be done under what’s known as ‘permitted development rights’.

These fast-track rules, created by the government, allow a host of alterations to be done without the hassle of having to make a full planning application.

Find out more about permitted development rights

That said, you should always check with your local council, builder or architect before starting work for peace of mind. It could save a lot of expense and heartache later.

In some areas, permitted development rights have been revoked, so it's worth checking what's allowed where you live.

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Extensions can be done using permitted development rights, but most will still require building regulations approval. 

A planning consultant or architect can help with the smooth running of the project, and guide you through all the required regs. 

If your home has already been extended, it may have already used up its permitted development rights allocation, so that’s worth checking with your local authority’s planning department.

And even if your extension does fall under permitted development, it’s a good idea to get a Lawful Development Certificate from your local planning authority before you begin. 

Find out more about Lawful Development Certificates

Single storey extensions

Under permitted development rights, you can build:

  • A 6m extension on a terraced or semi-detached home

  • An 8m extension on a detached home

  • The extension cannot be higher than 4m

  • Or higher than 3m if it’s within 2 metres of a property boundary

  • For a side extension, the width can’t be more than half the width of the original building

  • The extension cannot cover more than half of the garden

  • It must be built in the same or similar materials as the original building

  • In designated areas (that’s areas of outstanding natural beauty or conservation areas) you must seek planning permission, no matter how big the planned extension is.

Double storey extensions

Under permitted development, you can:

  • Extend a home by 3m for a double-height extension

  • It mustn't be closer than 7m to the rear boundary of the property

  • It mustn't cover more than half of the garden

Adding another storey to your house

Permitted development rights allow you to add one storey to single storey dwellings like bungalows.

If your home has two storeys, you can add up to two storeys, as long as: 

  • the total height of the house doesn’t exceed 18 metres

  • each storey isn’t more than 3.5m in height

  • The roof pitch remains the same as before

  • The storey is added to the main part of the house

Loft conversions

Under permitted development rights, you can:

  • Convert up to 50 cubic metres for detached and semi-detached homes

  • Convert up to 40 cubic metres for terraced houses

  • Insert dormer windows, as long as they aren’t higher than the existing roof space

  • The conversion must not exceed the height of the existing roof (otherwise planning permission will be needed)

  • The materials used must be similar in appearance to the existing house

  • Side-facing windows must be obscure-glazed

  • Windows must be non-opening if less than 1.7m from the floor of the room in which they are installed

If your plans exceed certain limits and conditions, such as extending or altering the roof space beyond its current structure, you will need planning permission.

A man holding a drill near to a double glazing door in a new room extension

Garage conversions

Most garage conversions can be done under permitted development rights. 

As garage conversions are all about making use of the space you already have (as opposed to building new rooms), you're unlikely to need full planning permission. 

However, building regulations mean that if you’re converting the space, or part of it, into an inhabited area, you’ll need building regs approval from your local authority.

If your garage is detached and you want to convert it into a bedroom or small annexe, full planning permission will be required.

And if your garage was built after your house, you'll need to check with your local authority that it hasn't already used up your home's permitted development allocation. 

The materials used will need to be similar to those in the existing house. 

Removing walls in your home

Normally, you wouldn’t need planning permission to knock down walls in your home, but you will need building regulations approval on structural and electrical works.

The exception is if your home is in a conservation area, in which case you will need planning approval.

Replacing windows, doors and roof lights

Planning permission isn’t normally required for replacing windows, doors or rooflights.

If you live in a conservation area however, you may only be able to replace like for like, so it’s definitely worth checking first.

If you’re planning to insert new windows to the side of your home on the first floor or above, you may only use non-opening, obscured glass, so that you’re not directly overlooking your neighbours.

Rooflights can be added under permitted development rights, as long as they don’t protrude more than 15cm from the roof itself.


Conservatories can be added under permitted development rights. 

As with other extensions under the permitted development scheme, building regulations approval will be required and certain guidelines must be followed.

Conservatories must be:

  • Under 30 square metres

  • Have exterior doors separating them from the rest of the house

  • Only half the area of land around the original house can be covered, and the conservatory can't be higher than the highest part of the existing roof. 

  • If the extension comes within two metres of the boundary, the height must be less than three metres. 

Garden rooms, sheds and summer houses

Most garden rooms don't require planning permission. They're classed as outbuildings, so you're allowed to build one as long as you comply with certain rules:

  • Your garden room or log cabin mustn't be in front of your home

  • The total area of all extensions, sheds and outbuildings around your home mustn't cover more than 50% of the total area of land around your house

  • The garden room must be single storey and less than three metres high (or four metres with a dual-pitched roof). If it’s within two metres of your boundary, the maximum height is 2.5 metres

  • The garden room mustn't have a balcony, veranda or raised platform

  • Any electrics and plumbing installed into your garden room will need to comply with planning regulations

  • If you intend to use your garden room for activities you might normally do in your main home, such as showering or cooking, you may need to apply for planning permission

9 things you might not know you need planning permission for

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