Planning Permission for Warehouses and Industrial Buildings

If you're planning to build, extend, or significantly change an industrial building or warehouse, you might be pleased to know you often won't need full planning permission. This is thanks to something called 'permitted development' rights. However, your project must strictly adhere to specific rules and conditions to qualify.

General Requirements for All Projects

Whether you're constructing a brand-new building or modifying an existing one, your proposed work must satisfy all the following criteria:

• Your development must remain strictly within the current boundary of the industrial building or warehouse (this boundary is known as its 'curtilage').

• You must not position any part of the new structure within 5 metres of that curtilage boundary.

• Building inside the curtilage of a listed building is not permitted.

• Should your site be located in a 'designated area' (like a National Park or an Area of Outstanding Natural Beauty), any external materials used for new or altered buildings must look similar in appearance to those already used on existing industrial buildings or warehouses there.

• You cannot reduce the available space for parking or for vehicles to turn around.

• For industrial buildings: The new, extended, or altered structure must be used for the building's current industrial purpose, to provide staff facilities, or for researching and developing products or processes.

• For warehouses: The new, extended, or altered structure must be directly linked to the warehouse's current use or for providing staff facilities.

• You must not use new, extended, or altered buildings to provide staff facilities under these specific circumstances:

  • Between 7pm and 6.30am, for employees who are not already working on the premises.

  • At any time, if your site contains a 'notifiable quantity' of hazardous substance (a specific amount deemed significant by regulations).

Specific Limits When Building New Industrial Buildings and Warehouses

When you construct a completely new industrial building or warehouse, you also need to meet these additional requirements:

• Height restrictions:

  • If your new building is constructed within 10 metres of the curtilage boundary, its height cannot exceed 5 metres.

  • Otherwise, your new building must not be taller than the highest existing building within your site's curtilage, or 15 metres – whichever measurement is the lower one.

• Gross Floor Space limits:

  • On designated land or a Site of Special Scientific Interest (SSSI), the total gross floor space of your new building must not be more than 100 square metres.

  • In all other locations, this limit increases to 200 square metres.

Specific Limits for Extending or Altering Industrial Buildings and Warehouses

If you're planning an extension or alteration to an existing industrial building or warehouse, these specific rules will apply to your project:

• Height restrictions:

  • Your extension or alteration cannot result in the building being taller than 5 metres if it's located within 10 metres of the curtilage boundary.

  • In all other situations, the extension or alteration must not make the building any higher than its existing structure.

• Gross Floor Space limits: The overall gross floor space of the building, including your proposed extension or alteration, cannot exceed:

  • 110% of the original building's size or 500 square metres (whichever is less) if your site is on designated land.

  • 125% of the original building's size or 1,000 square metres (whichever is less) if your site is a Site of Special Scientific Interest (SSSI).

  • 150% of the original building's size or 1,000 square metres (whichever is less) for all other locations.

Key Terms Explained

• How to calculate height: When you measure the height of any building you are constructing, extending, or altering, you should measure to its absolute highest point. This includes any features projecting above the roof, such as chimneys, flues, plant and machinery, or antennae. However, when you're comparing your building's height to the 'highest existing building within the curtilage', you should ignore these protrusions for that comparative measurement.

• Defining 'Original Building': If your site has several original buildings within the curtilage that are all used for the same business activity, these buildings are considered as a single 'original building' for measurement purposes. This means you should combine their gross floor space when you're calculating your limits.

Seeking Expert Advice and Legal Certainty

It's always wise to consult your local planning authority if you're unsure whether your proposed project qualifies as permitted development. They can offer guidance tailored to your specific situation.

For official, legal confirmation that your development doesn't require planning permission, you can apply to your local authority for a Lawful Development Certificate. This official document provides legal proof that your project is compliant with planning law.

Crucially, before you begin any work, always verify with your local planning authority whether any local restrictions on permitted development are in place for your area. These are often known as 'Article 4 Directions' and can remove your permitted development rights, meaning you would then need to submit a full planning application even for work that would normally not require one.