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How and when do you apply for planning permission?

Not every extension needs planning permission - but all of them need building regulations approval. If you're expanding or renovating your home, here's what you need to know.

Words by: Nic Hopkirk

Senior Editor

If you’re making major changes to your home, the chances are you’re likely to need planning permission.

Some developments are allowed under Permitted Development Rights, but it’s always worth checking.

Going ahead without permission and discovering later that you needed it will lead to a whole load of heartache and expense that’s best avoided.

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If you're using an architect, they will often submit the plans on your behalf. Ideally you’ll want to work with one who has a good track record for securing planning permission in your area.

If not, a good planning consultant can help you to get planning permission. 

They can also be helpful in determining local planning restrictions, targets and preferences to ensure your project is likely to get approval.

Find a local planning consultant near you

What projects can use permitted development rights instead of planning permission?

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’”, explains Jordan McCann, Principal Planner at Resi, the UK’s number one home extension company.

Find out if you can use permitted development rights with Resi's permitted development tool.

“Permitted development rights are rules created by the government that allow a host of alterations to be done without having to apply for planning permission."

“Permitted development gives you a comprehensive idea of what can be built without the subjectivity of a full planning application”, says Jordan. 

“Knowing first-hand what’s acceptable means you’ll be less exposed to hidden costs such as having to reapply. 

“Permitted development rights are a good option for anyone living in areas known for high planning refusals. They will also help direct your vision and give you a place to start from.”

Home improvements that don’t need planning permission

When you can use permitted development rights

“Some of the most common renovations which can be carried out under permitted development included rear extensions, loft extensions and outbuildings,” says Jordan.

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

“As garage conversions are all about making use of the space you already have, you're unlikely to need full planning permission to change their use.

“As long as you're not changing the shape of your existing roof, most loft conversions can be done without planning permission.”

You can use permitted development rights for:

  • Single story extensions up to 6 metres on terraced and semi-detached homes

  • Single story extensions up to 8 metres on detached homes

  • Extensions up to 4 metres in height, or 3 metres if it’s within 2 metres of a property boundary

  • Double height extensions up to 3 metres in depth, as long as it’s no closer than 7 metres to the property's rear boundary

  • The extension mustn’t cover more than half of the garden

  • And must be built in similar materials as the original building

When you cannot use permitted development rights

“There are three primary conditions that homeowners need to take into account if you want to extend under permitted development rights,” says Jordan.

"Keep in mind that permitted development rights have been revoked in some areas, so it's worth checking what's allowed where you live.

“If any of the following three conditions apply to your home, you will need to apply for planning permission.”

Has your home been extended since 1948?

“If your home has been extended by previous owners or by you since 1 July 1948, utilising permitted development may not always be possible."

Is your home listed or on ‘designated land’ (conservation area)? 

“Homes in these categories have either limited permitted development rights or have revoked permitted development rights. 

"We recommend getting some expert advice when planning your extension, just to be sure."

Is your property a flat?

"Flats and maisonettes will require you to apply for full planning permission as only houses are covered by Permitted Development Rights."

How do I apply for planning permission?

Most planning applications are submitted online.

Whether your project needs full planning permission, building regulations approval or both, you can submit your application at the Planning Portal.

Submit a planning application

You may need to make two separate applications if your project requires both planning permission and building regs, creating a separate account for each of the services.

If you’re planning major changes, it can be a good idea to meet with your local authority before submitting your application.

Some local authorities charge for this service, but it can be helpful in addressing any concerns they might have about approving your works.

You’ll need accurate drawings for the plans, including in-depth details on the materials you’re planning to use and information on any reinforcements that might be required.

When do you need a pre-application?

A pre-application involves having a formal meeting with a planning officer, explains Jordan Macann, Principal Planner at Resi.

“It’s a good idea to have a pre-application meeting if your project is a little more adventurous.

“You’ll discuss the feasibility of your ideas and any problems you could face with your planning application down the line.

“Following this, your planning officer might suggest changes for your architect to make before they submit the official planning application in order to increase your chances of success."

A pre-application can help you:

  • Explore creative and bold ideas without the risk

  • Anticipate changes before making your official planning permission application

  • Reduce how long it takes to get a response to your official planning application

  • Map out potential designs prior to buying a property if you’re looking to buy and renovate

  • Save money on the cost of design revisions, as you only need basic sketches at this stage

  • Move straight into making an official application afterwards.

When do you need building regulations?

Even if you don’t need full planning permission, you’re likely to need building regulations for major works, including extensions.

Building regs are needed for:

  • All new buildings 

  • Garages that are not fully detached and under 30 square metres

  • All extensions, no matter how small

  • Roof extensions, balconies and roof terraces

  • Basements and basement extensions

  • Some conservatories and porches (many are exempt but they must be separated from the house by doors and can’t be heated)

How long do planning applications take?

In most cases, it takes around 8 weeks for your local authority to grant planning permission.

The permission lasts for around three years from the date it’s granted.

How much does it cost to get planning permission?

Application typeEnglandWalesScotland
Full planning permission
Alterations or extensions to a single dwelling house or flat £206-£300
Alterations or extensions to two or more dwellings - houses or flats£407£460£600
Alterations or extensions to two or more dwelling houses or one or more flats-£460-
New dwelling house - no more than 50 houses£462 per dwelling£460 per dwelling£600 per dwelling
Outline planning permissions
Cost per 0.1 hectare of land (up to 2.5 hectares)£426£460£600
Householder permission
Alterations/extensions to a single dwelling house (not applicable to flats)£206£230£300
www.checkatrade.com/blog/cost-guides/planning-permission-cost/

Party wall agreements

If you’re planning any works that might affect the walls between yourself and a neighbouring property, you’ll also need a Party Wall Agreement. 

It’s important to apply for this when you put in your planning application to avoid delays, as they take around 10 weeks to process.

Party Wall Agreements are most commonly needed for:

  • Loft conversions

  • Digging foundations for an extension near a boundary

  • Damp proof courses

Before works can begin, you’ll need a written Party Wall Agreement from your neighbours.

You’ll need to give two months’ notice for any works that affect a party wall or boundary and one month’s notice for excavations.

You don’t need planning permission to serve a written Party Wall Notice to your neighbours and it can be done for free.

Download free letter templates for a Party Wall Notice and Agreement 

Alternatively you may wish to appoint a party wall surveyor to help.

Find a party wall surveyor near you

Your neighbour is given 14 days to respond to the notice.

If they assent to the works, you may wish to appoint a surveyor to assess the wall in question and note its condition to avoid any disputes later.

If your neighbour doesn’t respond within 14 days or dissents, a Party Wall Award is required from an independent surveyor chosen by you and your neighbour.

A Party Wall Award costs around £1,000, while surveyor’s fees are around £150-£200 an hour.

Once an agreement is reached, works can commence after two months and one day - and must have started within a year and a day of the agreement.

What projects need planning permission?

If you’re building a new dwelling, or subdividing an existing property, then you’ll need planning permission.

Large outbuildings and extensions, as well as any changes made to listed buildings or those situated in designated areas also need permission.

There are some surprising things that need planning permission that aren’t always obvious, so it’s always best to check. They include:

  • Any sheds or summer houses that are over 4m high with a pitched roof or 3m high with a flat roof 

  • Any fences, including a trellis, that are over 2m high - or adjoining a neighbouring highway

  • If you live in a conservation area, any changes to windows and doors that aren’t in keeping with the area 

  • Any driveways or patios laid using impermeable materials like concrete, tarmac or clay

  • Tree houses - because they’re likely to overlook a neighbour’s property

  • Raised timber decking that’s more than 30cm above ground level

9 things you might not know you need planning permission for


We try to make sure that the information here is accurate at the time of publishing. But the property market moves fast and some information may now be out of date. Zoopla Property Group accepts no responsibility or liability for any decisions you make based on the information provided.