The number of families registered as homeless in South Dublin County Council this month is up over 50%.
Figures released to Social Democrats councillor Dermot Looney reveal there are now 298 families on the council's books.
It is 100 more than in January last year.
Councillor Looney says local authorities need to step up development of social housing
"It's time that councils built more [social housing]," said Mr Looney.
"South Dublin, last year, did build in the region of 500 houses and there were a couple of hundred procured through other means.
"But that's still a drop in the ocean for the 10,000 or so people who are homeless and the housing list."