Belfast·SPG004 Residential Extensions and Alterations·Page 51
Permitted development for decking - location, siting and height
Raised platforms such as decking can be permitted development subject to controls on their location, siting and height.
Raised platforms… what is allowed without planning permission applies largely to location, siting and the height of the proposed raised platforms, such as decking.
Source — /Users/richardhill/Documents/planning-arch-project/data/documents/belfast/SPG004 Residential Extensions and Alterations.pdf