Local authorities will always have a level of vacancy in their housing stock. This will fluctuate over time, as tenancy surrender and re-letting of stock is an ongoing process.
Statistics in relation to the social housing stock are published by the National Oversight and Audit Commission (NOAC) in their Annual Reports on Performance Indicators in Local Authorities. These reports provide a range of information in relation to social housing stock, including the level of vacancy and turnaround times broken down by local authority. The most recent report, relating to 2020, is available on the NOAC website at the following link:
noac.ie/wp-content/uploads/2021/09/NOAC-Local-Authority-Performance-Indicator-Report-2020.pdf.