Another consideration: mold. Ireland is incredibly damp, and mold is a constant threat to the houses. I lived in Dublin, and we had mold behind the headboard of our bed, where the heat didn't penetrate (against an exterior wall). Even if you can handle that damp, bone-soaking cold personally (and it gets really freaking cold out west, in Galway and Donegal), you really need to warm a house in the winter to keep the mold at bay.