Threshold has called on the Government to introduce new standards for private rented accommodation.
The call from the national housing organisation came after it emerged that almost a third of properties inspected by local authorities had serious problems such as damp, vermin infestation or lack of hot water.
Despite the scale of problems in thousands of rented properties across the State, the organisation said that legal action was only taken by local authorities in four cases.
Threshold chairwoman Aideen Hayden said the wrong message was being sent out to landlords. She called for local authorities to step up inspections, prosecute more cases and name and shame those found guilty of breaches.
Ms Hayden said the Government must ensure that existing standards were enforced and should introduce new standards which reflected current accepted living standards.
However, the scale of sub-standard accommodation in the private rented sector was questioned by the Irish Property Owners' Association which said there had been a dramatic increase in the supply of high-standard accommodation.
Also yesterday, Threshold said much of Dublin's older apartment houses were fire traps which were overcrowded and were potentially lethal.
The agency's comment came after it emerged that 30 people were living in a Georgian house which went on fire on Ormond Quay on Sunday.
On the general issue of fire safety in older buildings, Threshold said all new multistorey apartment blocks had to have a fire safety certificate, but this was not required for older buildings.
It is not known whether the building that went on fire on Sunday had a fire certificate.
Ms Hayden said it was her "clear understanding" of fire safety regulations that older buildings were not deemed to be in breach of fire safety regulations until they had been inspected and an improvement notice issued.
"So if you have not been inspected, you are technically not in breach," she said.
Older, cheaper rental accommodation was being taken up by those with the least resources, frequently the immigrant community, she said. Some of these older houses were typically converted to bedsits pre-1963 and as such were exempt from planning permission.
However she said they were very often "fire traps, even if they are not technically in breach of the fire regulations".
Ms Hayden said there was a "significant amount" of private rental accommodation where landlords were not installing fire escapes. Threshold has called for the introduction of "an NCT for private rented accommodation".
The Dublin City Council press office was unable to say what the fire safety regulations were for older houses. A spokeswoman said a fire safety officer would be available to discuss the issues this morning.
The press office said it could not reveal details of the ownership of the house on Ormond Quay which went on fire. Residents said the building was divided into nine flats, many of them bedsits. Bunk beds could be seen in rooms that were also used for cooking and washing. The fire broke out in the hallway, activating a fire alarm.
However, as the only access to the street was through the hallway, those on the upper floors were trapped.
Five residents had to be rescued from an enclosed yard at the back of the building.