The latest figures on the private rental market in Ireland show there has been a further increase in rents.
The Private Residential Tenancies Board said there was an average increase of just over 10% in rental costs in Dublin during a period of 12 months, ending last June.
The PRTB has 300,000 registered rental properties.
One in five households now live in private rented accommodation.
The average rent in Dublin has increased by 10.5%, but the increase was over 12% for apartments.
Outside Dublin, rents increased in the same period by 2.6%
The PRTB said the latest figures show there is a demand in Dublin for smaller units such as apartments, which currently make up just over half of all of the city's rental properties.
The figures show tenants earning the average industrial wage of €36,000 are now paying 41% of their net income to rent an apartment.
PRTB Director Anne Marie Caulfield told RTÉ's Morning Ireland: "56% of registrations with us in Dublin were for apartments ... for those smaller units.
"But the affordability as you say for a person on the average industrial wage of €36,000, means that they're now spending 41% of their net income after taxes on their rent and the affordable or the sustainable level would be 30%."