What is planning permission and do I need it?

Planning permission (sometimes known as planning consent) refers to the approval given by the local authority under the power given to it by the 1948 Town and Country Planning Act to allow the building of, or changes to, a building. Its primary purpose is to ensure that any proposed development aligns with local planning policies, considers the impact on the surrounding area, and adheres to design and safety standards.

The planning application process:

1. Contact your Local authority

It’s always best to contact your local planning department to find out if you need to apply for planning permission before you submit an application – they will be the ones reviewing it. Not all building work, extensions or home alterations need planning permission, some changes fall under what’s known as permitted development. You can find out who your local authority is here.

2. Submit your plans

Planning applications are submitted and administered via an online planning portal, which is differs depending on where you live in the UK:

3. Your application is assessed

Your local authority considers your application and gathers public feedback from your neighbours to help make their decision. They will provide feedback via the portal and you may need to amend your plans and re-submit them. Both planning permission and building regulations approval may be needed for your work. Local authority Building Control (LABC) offer practical advice on building regulations for homeowners on their Front Door website.

What are the guidelines for:

Building an extension

In the case of complete new builds, some larger extensions, and conversions (eg changing the use of a building from a barn to a house) planning permission will almost always be required, and if you live in a listed building you will need Listed Building Consent.

In many cases, small extensions might qualify for permitted development, meaning you don't need formal planning permission. However, specific size and design limitations apply, for example:

  • Extensions exceeding 50% of the original house area (as built or existing on July 1st, 1948).
  • Extensions exceeding a certain height or depth (this varies depending on the type of house and land around it).
  • Extensions built to the front of the house facing a road.

Local restrictions and different rules for listed buildings may apply – see below.

Renovation work and conversions

Some renovation work needs planning permission, as do most conversions (eg changing the use of a building from a barn to a house). Planning permission is not required in all cases, but always check with your local planning department if you’re in any doubt. Minor alterations may well be allowed under Permitted Development.

Building a new house

Building a new house always requires full planning permission. This allows the local authority to assess the project's impact on the surrounding area and ensure it aligns with planning policies. They need to assess:

  • Impact on surroundings: Ensuring the new structure fits well with the existing neighbourhood in terms of size, style, and how it will be used.
  • Environmental considerations: Assessing potential impacts on the environment, such as drainage, ecology, and traffic.
  • Infrastructure and services: ensuring the area can support a new home with roads, utilities, and local services (like schools and healthcare).
  • Planning policies: New homes must comply with local and national planning policies that guide how an area should develop over time.

Listed buildings

Anyone living in a listed building must obtain Listed Building Consent from their local authority before starting any building work, including alterations or extensions that will affect the building’s character as a building of special architectural or historic interest — it is a criminal offence to carry out work requiring listed building consent without obtaining it first. You might also need consent to carry out work to any outbuildings in the grounds if your home is listed.

It’s also worth noting that planning permission might be needed in addition to Listed Building Consent. Contact the planning or conservation officers at your local planning authority to find out.

To check if your building is listed, visit:

Designated areas

Buildings located in designated areas, such as a Conservation Area, Area of Outstanding Natural Beauty or within a National Park, have an extra layer of scrutiny applied to any renovation or extension work. You can check with your local authority if your property lies within one of these areas.

In properties within these ‘designated areas’ permitted development rights tend to be more restricted, and you may well need to apply for planning permission for types of work that would not otherwise require an application.

One of the main restrictions placed on buildings within Conservation Areas tends to be when it comes to demolition. You will need planning permission in order to demolish a building within a Conservation Area unless:

  • The building you are demolishing (garages and outbuildings, for example) is less than 115m3 (measured externally).
  • The building was built after 1914 and was used for agriculture or forestry.
  • You want to demolish a gate, wall or fence less than 1m high abutting a highway or 2m high elsewhere. 

The best advice is to contact your local planning authority to discuss your proposals — they will tell you whether or not your development will be permitted.


What happens if I build without permission?

If you go ahead with a project that requires planning permission without first gaining consent, your local authority might request that you demolish it or submit a retrospective planning application for work carried out without consent, although this does not mean permission will be granted. If the retrospective application is refused, the local authority could issue you with an enforcement notice meaning you will have to reverse the work.

You should also be aware that properties that have had work carried out to them illegally are unmortgageable — a problem that will most definitely come to light should you try to sell.

What is outline planning permission?

Another option available is to ask your Local authority for a pre-application planning meeting.

This can be used to discuss your plans and get advice from a member of the planning team before submitting your application. They will typically be able to flag any obvious issues with your plans, giving you time to amend them.

Builder helping clients with house plans

What is permitted development?

Permitted development is a scheme that allows homeowners to undertake specific home improvement projects, like small extensions, without needing formal planning permission from the local authority. However, it's important to remember that these rights don't apply to flats, maisonettes, some newer homes and listed buildings.

Things to consider

  • Live in a designated area? Restrictions may apply in areas like Conservation Areas and AONBs, so double-check with your local authority.
  • Article 4 directions: Local authorities can remove permitted development rights in specific areas to protect their character – a full planning application will be needed for any changes.
  • Prior notification needed? Even if your project falls under permitted development, you might still need to inform your local planning authority beforehand.
  • Not a free pass: Permitted development doesn't bypass other necessary approvals, such as building regulations.

Lawful development certificate

It’s a good idea to apply for a Lawful Development Certificate for any work you do under permitted development. If you decide to sell your property, being able to prove that your building work is compliant with planning regulations will leave no ambiguity for the buyer and can help to smooth the sale process. You can apply for one via the planning portal in your region, but note that a fee is usually applicable.

Permitted development rights fall into various categories:

  • Class A: Extensions (enlargement, improvement or alteration). This allows the construction of:
    1. a single storey side extension up to half the width of the existing dwelling.
    2. a single storey rear extension up to 4m in length for a detached dwelling and 3m long for a semi or a terraced house.
    3. in some instances, 3m two-storey rear extensions.

      You should note that changes made in May 2019 made it permissible to construct single-storey extensions of up to 8m – or 6m for semi or terraced houses – under Class A, but they will require ‘prior notification’ (see below).
  • Class B: The Roof. Rear dormers and hip-to-gable extensions can be created providing the additional volume does not exceed 50m3 (or 40m3 in the case of semis or terraced homes).
  • Class C: Other roof alterations
  • Class D: Porches
  • Class E: Outbuildings etc. Outbuildings can be erected within a residential curtilage, providing they sit behind the main (usually the front) elevation and do not cover more than 50% of the curtilage. They should not be more than 3m in height (4m for dual-pitched roofs or 2.5m if within 2m of a boundary).

Read our ultimate guide to permitted development rules for further information. 

Prior approval

Prior approval (previously known as the ‘neighbourhood consultation scheme’) is required from your local authority for specific types of permitted development. It means that before you begin work, you must notify the local planning authority of the details of the project before work can begin. 

Prior approval takes around eight weeks to process and mainly applies to:

  • Larger home extensions: Larger extensions of between 4 and 8 metres to the rear for detached houses, and between 3 and 6 metres for others generally require prior notification.
  • Change of use: If you're converting a building from one use to another (eg shop to house), prior notification might be needed. This depends on the specific class of commercial premises involved and local planning regulations.

The local planning authority will notify boundary neighbours, and if no objections are received (or considered to have any merit), and the local planning authority is happy that there will be no adverse impacts from flooding, highways or contaminations, then a Lawful Development Certificate will be issued.

How it differs to planning permission:

While prior approval involves informing your local authority, it doesn't require their formal approval. They will assess your notification and may raise concerns or require minor adjustments (regarding choice of materials for instance, or whether your plans meet the objectives of the National Planning Policy Framework. However, they cannot block the development if it truly falls under permitted development rights.

How to obtain prior approval:

  1. Check the specific project type: Determine if your planned development falls into a category requiring prior notification. Resources like the Planning Portal website (https://interactive.planningportal.co.uk/) or your local authority website often offer guidance on which projects fall under this requirement. Builder assessing plans on site
  2. Consult your local authority: Contact your local authority's planning department. They can confirm if prior notification is necessary for your project and provide detailed information on the process.
  3. To submit an application for prior approval, go to:

How to make a planning application

What do I need to submit for an online application?

Along with the application form, you will need to submit the following if you apply online:

  • Location plan.
  • Site plan.
  • Elevations of both the existing and the proposed designs.
  • An ownership certificate.
  • A design and access statement.
  • An ‘Agricultural Holdings Certificate’. This confirms whether any of the land relating to the application is part of an agricultural holding and is necessary even if your application is for a non-agricultural use. The certificate is available from the forms section of your application.
  • The correct fee.

How long does planning permission last?

Planning permission lasts for three years from the date when full consent is given, in most cases. In other words, you must begin building work within this time. Once work has formally commenced (which is after the first building regulations inspection) planning permission lasts forever.

How much does planning permission cost?

The cost of planning permission varies depending on where you live in the UK. Currently, the costs are as follows:

  • £578 for a full application for a new house
  • £258 for an extension application (also known as a householder application)
  • £578 per 0.1 hectares for outline planning permission, if site is less than 0.5 hectares
  • £460 for a new dwelling
  • £230 for a householder application
  • £460 per 0.1 hectares for outline planning permission, for sites not in excess of 2.5 hectares
  • £600 for a full application for a new house
  • £300 for an extension application
  • £600 for outline planning permission

Northern Ireland

Prices correct at March 2024.

How long does planning permission take?

The whole process can take as little as eight weeks, but more complex designs can take longer. The process includes:

Public Consultation
  • Application Display: Upon submission, a notice detailing your proposed project will be posted outside your property.
  • Neighbour Notification: Your neighbours will be informed and invited to review the plans and provide feedback during a three to eight week public consultation period.
Additional Consultations
  • The local highways department and potentially the Environment Agency may be consulted by the authority.
Revisions and Additional Applications
  • In some instances, revisions to the initial plans may be required, necessitating additional applications, and potentially extending the timeframe.

It’s worth noting that even after receiving planning permission, specific conditions might be attached regarding materials, such as bricks or roof tiles, for example.

While you wait, use the waiting period productively, so you’re ready to get going as soon as possible.

  • Find a builder for your project
  • Secure the best deals on materials
  • Draw up a schedule of works


Why might I be refused planning permission and what do I do about it? 

If your application is refused you have two choices. You can either:

  1. amend your plans in accordance with the local authority’s reasons for refusal and resubmit; or
  2. make an appeal, free of charge.

In either case, you need to ascertain the reasons for your refusal in order to move forward in a way that will result in a positive final outcome.

Public consultation

Once you have submitted your application, there will have been a period of ‘public consultation’ lasting between three and eight weeks. During this time, anyone who might be affected by your proposals is consulted. They may raise objections, although these do not always impact the final decision of the case officer in charge of your application.

If, during this period, it looks like your application will be rejected, you have the option to withdraw the application, make changes you think necessary, and resubmit — free of charge (if done within 12 months).

If your application is refused, you will receive a formal notice of refusal, listing the reasons the application has been declined. If there is anything on the notice you don’t understand (planning jargon can be difficult to decipher), you can ask the planning committee or the case officer.

Reasons for refusal vary, but range from your building work being outside the development boundary to it having a negative impact on the surrounding environment. Sometimes, the privacy rights of neighbouring homes are cited as a reason for refusal, or the changes you are making are deemed out-of-keeping with the local street scene.

The appeal process

If you choose to launch an appeal, then it must be lodged within three months. Details of how to appeal are sent out with refusal notices, which usually states which local planning policy your application contravenes — as a result of this, any appeal you lodge must show how this will no longer be the case.

If you decide to stick with your original plans, your appeal should include all the reasons why you think your application should have been granted permission. You must also complete forms that will be sent to you from the council. It can help to use the services of a planning consultant, although you will need to factor in the cost of doing this.

The council must respond within six weeks of your appeal being submitted, after which you have three weeks to respond again. Then a planning inspector will visit your site and give their decision on the appeal within two to six weeks of their visit — appeals can take from around five months.

Resubmitting your application, with an amended set of plans, that take into account the original reasons for refusal, is likely to be more straightforward than the appeals process.

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