There is no single official “average rent increase” for every Kilkenny tenancy. The RTB Rent Index publishes average rents for Kilkenny by property type and tenancy, so you can compare the latest figures with an earlier quarter to estimate the market change. However, a landlord cannot automatically apply that average to your tenancy: the permitted increase depends on your tenancy start date, the rent-control rules in force and the required notice procedure. Check the latest RTB guidance or speak to a housing solicitor if you are challenging a proposed increase.