Dún Laoghaire-Rathdown County Council spent more than €200,000 refurbishing one void housing unit in Sandycove last year.
The council spent in excess of €600,000 doing up five units in 2018, which also included one property in Sallynoggin (€119,447) and three units in Ballyogan (€262, 913).
Voids occur when tenants vacate houses or flats, either transferring to somewhere more suitable or leaving to purchase their own property. The death of a tenant or a marital breakdown can also result in a void unit.
The figures were released to The Irish Times under the Freedom of Information Act.
The council said the properties required “major refurbishment works” due to their condition and included works such as new bathrooms, kitchens, electrical rewiring, heating, new windows and door, part demolition and rebuild.
The council said “re-let repairs” were also carried out on 155 properties last year, at a total cost of €1.3 million.
It said the average time to re-let properties is between 12 and 13 weeks and there are currently 65 properties vacant out of a total housing stock of 4,753 units.
“This average time compares favourably with that of other local authorities and the average national time taken which stood at 20.9 weeks in 2016,” it said.
Dublin City Council (DCC) spent more than €25million refurbishing 969 void units last year, an average cost of €25,866 per unit.
Dublin City Council has a housing stock of 24,454 houses and apartments with 1.91 per cent of this currently void and in the process of being refurbished.
The council spent almost €16m refurbishing 879 void houses and apartments in 2017, an average cost of €18,037 per unit.
It said the increase in the cost was due to several factors including a large number of properties needing refurbishment in “old flat complexes”, such as Dolphin House, Oliver Bond House, Raheny Court, Markievicz House, Pearse House, Verschoyle Court and Tyrone Place.
“Extensive works are often required to bring these properties up to current standards,” said a DCC spokesman.
A higher number of houses being refurbished last year in comparison to 2017 also brought up the costs along with 159 of the properties newly acquired stock which “typically require extensive works”.
The average time to refurbish a property last year was 15.4 weeks.
“Dublin City Council is satisfied that the investment it makes in refurbishing its housing stock enables it to significantly improve the quality of housing for our residents and that the investment represents good value for money,” the spokesman added.