DUBLIN — To visit Graham Usher’s dream apartment in Priory Hall, the most notorious of Ireland’s ruined ghost developments, is to see what Ireland aspired to be, and what it became instead....

If Ireland’s rise was one of the most spectacular in Europe, its fall was one of the most precipitous, with a boom in the 1990s leading to a housing bubble in the 2000s that burst spectacularly when the banks fueling it threatened to collapse. In 2008, the government made an emergency decision to guarantee the banks’ debts, thus condemning the country to brutal austerity that has left it impoverished and weighed down by debt of its own.

Priory Hall is only the worst example. More than 2,000 developments begun during that period have turned into “ghost estates,” unfinished or vacant housing projects with 10 or more units that were meant to create communities but are now quietly rotting. Others, built under a system that allowed developers to “self-certify” — meaning that they could unilaterally declare, with only minimal government oversight, that their properties complied with building codes — are now falling apart, even while residents live there....