The Town and Country Planning (Use Classes) Order 1987 puts uses of land and buildings into various categories. Planning permission is not needed for changes of use within the same use class unless a planning condition has been imposed restricting this.
User Inspectorate PED Art. 16 (UI)
A conformity assessment body notified to carry out the tasks set out in Article 16 of Directive 2014/68/EU on Pressure Equipment (PED)