The price of rent in rent pressure zones would be higher if they did not exist, a new report has found.
The report by the Residential Tenancies Board found that rent in rent pressure zones would be up to 3% higher if the measures had not been implemented in 2016.
Under the legislation, landlords cannot increase rent by more than 4% a year.
However, according to the report, over half of tenants living in rent pressure zones do not realise there are such restrictions on their landlords.
The majority of respondents said they felt secure in their tenancy.
There are now 42 rent pressure zones across 13 counties, accounting for 65% of renters
Director of the Residential Tenancies Board, Rosalind Carroll, says tenants don't realise that the rule also applies to new tenancies.
"Rent pressure zones and the cap on rents in terms of that 4% increase applies not only to existing tenancies but to a tenancy that is being re-let on the market," she said.
"So lots of people get that it applies within your existing tenancy but the research found that a lot of people didn't get it at the re-let stage and that's something we had thought for a while and the research concludes on that as well."