Residents were evacuated from Thornfield Square Apartments Watery Lane, shortly after 5.30am.
However, 10 adults and three children had to be lowered to safety from balconies and windows.
A total of 10 units from Dublin Fire Brigade rushed to the scene after the alarm was raised by a resident who spotted the fire in a hallway.
Ambulances brought one resident to hospital, while several others were treated for smoke inhalation at the scene. It is understood that nobody suffered any serious injuries during the incident.
A Garda spokesperson said it was too early to tell if the blaze had been started maliciously.
Water damage to a number of properties was reported, although most residents were expected to be allowed to return to their homes following the completion of a forensic examination. Fire safety personnel will also probe reports that the fire doors on the hallway were jammed open.
Meanwhile, Socialist Party TD Joe Higgins claimed the fire hazard of homes highlighted in a housing estate in north Dublin was emblematic of a widespread legacy of a catastrophically lax regime of building regulation and safety compliance.
He called on Environment Minister Phil Hogan to stop allowing the Government to wash its hands of the State’s role in permitting builders to deceive home buyers into purchasing unfit and unsafe homes.
Speaking during a visit to homes in Belmayne near Clongriffin, Mr Higgins said they represented another example of the boom era workmanship, where overpriced homes contained structural flaws which could potentially threaten lives in the event of a fire.
He criticised the minister as well as the fire authorities for seeking to portray the issue as a purely civil matter between the home buyers and builders.
“These homes were built within a planning and building regulations framework for which various branches of government hold stat-utory responsibility. This regulatory framework has proven to be historically lax and unenforced,” said Mr Higgins.
It emerged last year that up to a quarter of the 960 houses and apartments in Belmayne could pose a serious fire risk.