Funny enough, I _did_ build a house in the countryside, and as an immigrant, but only by buying a very old house and refurbishing/extending it. I hardly view this as a claim on the public purse; I imported my job (by working remote for a US company), dumped hundreds of thousands of Euro in to Ireland (half a million just in taxes), then built a house after working with asinine planners and finally sold it at a huge loss. So Ireland got a bunch of money and another house. They're welcome.
As far as Ireland's demography, I don't see how people immigrating (mainly to the cities) changes what I said? Ireland is noteworthy in that it _also_ has a huge problem with emigration; it treats nurses terribly and more or less pushes them out the country, for instance.