Planning permission is needed for a temporary building if it is intended to be used for more than 28 days, and/or it will be bigger than 100 m², with some exceptions for building extensions. In all other circumstances planning permission is required, but retrospective applications may be made in an emergency or in cases of urgent need.
When Planning Permission is NOT Required
Under some circumstances, you may not need planning permission for your building, for instance if the structure has a floor space of less than 100 m² AND it is not going to be used for more than 28 days.
If the structure is an extension to an existing building, you may be able to avoid a planning permit if your building meets the following criteria, even if it is destined for longer term use:
- The building is shorter in height than the original building, and
- The temporary building is directly relevant to the purpose of the original structure, and
- The structure is less than 25% of the size of the original by volume.
When You Need Planning Permission
As a rule of thumb, if you plan on using your temporary structure continually for more than 28 days, and/or it will be bigger than 100 m², you should be prepared to submit a planning application to your local authority.
You will also need planning permission if any of the following apply:
- The building exceeds 25% of the total area available on your site, or in the case of warehouse and factory extensions, is more than 25% the size of the original building.
- The temporary building comes closer than 5 m to the boundary of your site
- The building significantly reduces the amount of land available for parking, and/or manoeuvring of vehicles.
When to Make Your Application
In most circumstances, we recommend making a planning application before you purchase or install your temporary structure. Submit the application with as much time as possible. This ensures you’re covered and there are no issues with your local authority. However, a planning application can take anything from 8 to 12 weeks, which can pose a problem if the structure is needed urgently. For this reason, some businesses choose to go ahead without planning permission. In this case, it is possible to acquire retrospective planning permission, if you can prove that the building is needed on an emergency or urgent basis.
In most genuine cases, the local authority concerned will grant retrospective permission without issue. However, if permission is not granted the authority could require you to restore the site to its original condition – i.e. request you to remove your temporary building. Failure to comply could result in an enforcement notice.
if you plan to use the temporary building for more than 28 days and it’s going to be bigger than 100m2, you should make an application to your local authority for approval.
Whether you do this before you have the temporary building installed, or whether you make a retrospective planning application due to the urgency of the space requirement, is entirely your decision.
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Our in-house planning service
Handle every planning application on your behalf in-house.
Every planning application we handle is managed totally in-house by our structural Engineer, Ross Vinter.
With a first-class honour's degree from Herriot Watt University, Ross’s structural engineering expertise is a huge benefit when handling planning applications on your behalf.
This also extends to him dealing with the Highways Agency, environmental agencies, and Building Control Departments to satisfy any requirements each may have.
We are able to provide a complete planning service. Using our own team of professionals we are able to advise on every aspect of planning permission for your specific requirements.
Fuller details are in our planning guide which may be downloaded from this page.
Government requirements Government Website
Factory or warehouse extensions
Planning permission will not normally be required if your extension is:
- less than 100 square metres of floor space; and
- less than 25 per cent of the volume of the original building; and
- below the height of the original building.
- The extension must be related to the current use of the building or the provision of staff facilities.
Planning permission will be required if the extension:
- materially affects the external appearance of the building; or
- comes within five metres of the boundary of the site; or
- reduces the amount of space available for parking or turning of vehicles.
Applications should take between 8 - 12 weeks.
If you go ahead without permission, the local council (or National Park Authority) may ask you to make a retrospective planning application.
If it decides permission should not be granted it may require you to put things back as they were. You can appeal but if the decision is against you and you refuse to comply you may be prosecuted.
But if you only want the building for a relatively short period of time this may well be a risk worth taking as the building may well be removed before any enforcement order is applied. Whatever you decide the risk lies with you.
Our recommendation and practice
Simply we recommend that you should obtain permission, other than in the clear exemptions above. However, you can have the building installed, and then make a retrospective application, but you do risk having to have the building removed prematurely if enforcement action is taken against you.
Try contacting your planning office and take some soundings. Based on the response consider the best way forward. Let us then handle the application for you. It can, and most probably will, take months – time you may not have. But if an application is submitted as you decide to install the building it will be treated as a retrospective application as soon as the building is installed. But if you have a clear and urgent need this should not be an issue.
You can make a retrospective planning application if your need is urgent or in an emergency.
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