"Revenue have stated ... Where a building contains units that are not suitable for use as dwellings in their own right, such as a bedsit, the building as a whole should be valued for LPT purposes and one LPT Return should be filed.
Where an individual residential property within a building is suitable for use as a dwelling in its own right, (e.g. a self-contained dwelling such as an apartment) it should be valued as a single residential property for LPT purposes."
from http://www.*****************.com/landlords-and-the-property-tax.html