Sui generis use class in planning
The Town and Country Planning (Use Classes) Order categorises uses of land and buildings. Developments may not be used for purposes that are not within the use class for which they received planning permission.
Changing the use of a development from one class to another may require planning permission, although changes of use may be permitted without the need for a planning application for certain allowable uses (for example changing a restaurant into a shop - see permitted development).
‘Sui generis’ buildings are those that do not fall within any particular use class. The Latin term 'sui generis' means ‘of its own kind’. It is a term used to categorise buildings that do not fall within any particular use class for the purposes of planning permission.
There are, however, permitted development rights that allow movement between some sui generis uses and other uses. There is a common misconception that changing the use from an existing use class to a sui generis class always requires planning permission. Permission is only required if the sui generis use is materially different from the existing one.
If there is any doubt, a lawful development certificate can be applied for. This must include a detailed and unambiguous description of the use, operations or other matter for which it is to be granted. The characteristics of the matter should be spelled out in detail to avoid future problems of interpretation.
Sui generis buildings include:
A material change of use from a sui generis use, or to a sui generis use, will require planning permission.