For the purposes of these charges, there is a material change of use where there is a change in the purposes for which, or the circumstances in which, a building is used, so that after that change.
At ddibenion y costau hyn, mae newid ar ddefnydd materol pan fydd newid yn y dibenion, neu yn amgylchiadau defnyddio’r adeilad, felly ar ôl y newid hwnnw.