A dwelling is somewhere that is, was previously, or once completed or adapted, will be suitable for occupation as a home, providing all the necessities for habitation (such as a kitchen and bathroom).
Fel gofyniad sylfaenol, roedd yn gymwys (ac mae'n dal i fod yn gymwys) i rannau cyffredin, sef yr ardaloedd sydd at ddefnydd yr holl breswylwyr fel cynteddau, grisiau a phennau grisiau.