Over the next three decades, Ireland needs to build something like two million homes. The country has around two million homes today and, by mid-century, on any reasonable reading of population growth and in particular shrinking household size, it will need closer to three and a half million.  Once you add in the older stock that will have to be replaced along the way, the total number of homes needed to be added comes to roughly two million – and delivered in 30 years. It sounds like a bold claim but, believe it or not, €2 billion of public money…