DUBLIN, April 6 (Reuters) - Ireland built an average of just 6,700 homes a year between 2011 and 2016, census data showed on Thursday, over a third fewer than suggested by the statistics the government relies on to tackle a chronic housing shortage.
While Ireland was left with a surplus of houses after values were cut in half following the bursting of a property bubble in 2007, a recovery in its construction sector has lagged behind a rapid economic turnaround and led to supply falling far short of demand.
Ireland's government has pledged to double housing output to 25,000 by 2019 and has pointed to progress in data it publishes that showed the number of house completions as measured by new electricity connections rose to almost 15,000 last year from a low of 8,300 in 2013.
Some analysts have criticised the government for using that measure as a true reflection of activity as it effectively double counts large swathes of new builds left vacant when the market crashed that have been recently reconnected to the grid.
The census backed up that analysis by showing that in the five years to the end of April 2016, 33,400 houses were built compared to the 51,600 measured by new electricity connections.
Other indicators have shown construction activity picking up over the last year.
Yet the lower base means Ireland may face a longer wait to hit the at least 25,000 annual builds that analysts say are needed to keep up with demand in a population that is also growing three times faster than the euro zone average.
The slow supply response has accelerated house price growth again in recent months to a year-on-year average of almost 8 percent, while residential rents have already risen back above their "Celtic Tiger" peak.
The census data also showed that the average household size increased to 2.75 persons from 2.73 persons in 2011, a reversal Trinity College Economics Professor Ronan Lyons described as an "astonishing result" as the figure had been falling steadily for decades.
With more and more young workers either living at home with their parents for longer or having to share accommodation in greater numbers, Lyons said the change in the household size trend was a "damning indictment of inadequate housing supply." (Reporting by Padraic Halpin; Editing by Toby Davis)