The introduction of rent pressure zones in 2016 has resulted in a 'two-tiered rented sector' with tenants in different parts of the country offered different protections.
Housing charity Threshold has called for an urgent overhaul of the private rental market in the wake of ongoing increases, despite the introduction of measures such as the rent pressure zones (RPZs).
The government this week designated two additional RPZs, bringing the total number to 23 nationally. Rents in Navan and Limerick City East can now only be increased by 4% per annum as has been the case in Cork and Dublin since December 2016 when then-Housing Minister Simon Coveney signed off on the creation of RPZs for an initial three year period.
But Threshold says the allocation has come far too late and that the issue is escalating in other parts of the country too.
"We have been highlighting for some time the rising rents in places such as Limerick and Waterford," said a spokesperson for the charity.
"Tenants in Limerick City East pay €266 more per month in rent as of Q4 in 2018 compared to Q4 in 2016, an increase of 31% since RPZs were introduced in Dublin and Cork."
In the same period, rents in Navan were 32% higher.
Areas such as Dundalk South look set to go on a similar trajectory, as rents there jumped €125 or 13.2% from Q3 2018 to Q4 2018. They are now within €58 of the national average.
In Portlaoise and West Mayo, rent has increased by more than 7% in each of the last six quarters but the average rent remains below the national average and, as such, neither area has been designated an RPZ. Similar trends have been seen in Trim and Tullamore, where rent increased by more than 7% in five of the last six quarters.
RPZs need to be extended nationally, Threshold said.
"All tenants should be afforded equal protection, regardless of geography," the spokesperson said.
"The experience of tenants in Limerick City East and Navan needs to inform future policy to ensure that tenants elsewhere do not have to experience the same level of rent increases for prolonged periods in order to be afforded the protection of the RPZs."