If you want a definite yes or no answer about whether or not you need planning permission you can submit an application for a Lawful Development Certificate (LDC).
Os ydych am gael ateb pendant ar ba un a oes angen caniatâd cynllunio arnoch ai peidio, gallwch gyflwyno gais am Dystysgrif Datblygu Cyfreithlon (TDC).