You can apply for a Lawful Development Certificate (PDF 479 KB) ​ ​​​​​​​​​​​External link opens in a new window ​ by downloading and filling in the form.
Gallwch wneud cais am Dystysgrif Datblygu Cyfr​eithlon (479kb PDF) ​ ​​​​​​​​Dolen yn agor mewn ffenestr newydd ​ drwy lawrlwytho a llenwi’r ffurflen.