a lease of a building which is varied, for example, where additional floors are added to a building held on the old lease such that the variation gives rise to a surrender and re-grant of the lease
bydd les adeilad sydd wedi’i hamrywio, er enghraifft, pan fydd lloriau ychwanegol wedi’u hychwanegu at adeilad ar yr hen les, fel bod yr amrywiad yn arwain at ildio ac ail roi’r les