It is taking more than a year to get social housing units ready for new tenants after they have been vacated in some parts of the country.

Figures obtained by RTÉ show that in Cork county it takes an average of 66 weeks to get a property ready for a family to move in.

In Donegal, it can take up to 44 weeks and in Kerry it is taking an average of 55 weeks.

The figures show that the problem is more acute in rural counties when compared to Dublin, where the average time between one family moving out and another moving into a unit is around 13 weeks.

Mayo and Waterford city were also among the councils that turned properties around relatively quickly.

Many of the county councils cited major repair works as a reason for dwellings being vacant for such long periods.

Some county councils said housing units known as voids that were vacant for a long period of time required considerable refurbishment.

Some counties, such as Donegal and Leitrim, also said that there can be a difficulty in re-letting units in rural and isolated locations due to lack of demand.

Funding was also an issue in some counties, which said houses had been left idle up until 2014 when funding became available through the government's voids scheme.

Director of services with Kerry County Council, John Breen, outlined the reasons why it is taking an average of 55 weeks to turn properties around in Kerry.

"The first thing to consider is to put the number of vacant properties into context in Kerry - it's less than 3% of our total housing stock.

"The reasons as to why the period of time might appear long I suppose relates to a number of factors. Most particularly, the fact that when a property comes back to the local authority it may be the first time in quite an amount of time and we take the time to upgrade the property to the modern standards.

"Equally we may have properties like single rural dwellings in relatively remote areas where we don't have the demand for them so it takes longer to source the tenant and then to repair the property," he said.

Homelessness organisations such as the Simon Communities have called for a stocktake system to be implemented as a matter of urgency so that it is known exactly how many units are vacant across the country at any given time.

Spokesperson for the Simon Communities Niamh Randall said the amount of time it is taking to turn properties around was outrageous when you consider there are 90,000 people on the social housing waiting list.