In dwellings - installation of fixed low or extra-low voltage electrical installations: BESCA, Blue Flame Certification, Certsure, NAPIT, OFTEC, Stroma
Mewn anheddau - gosod gosodiadau trydanol foltedd isel neu isel iawn: BESCA, Tystysgrif Blue Flame, Certsure, NAPIT, OFTEC, Stroma