About 900 people live in 300 apartments in the Longboat Quay complex in Dublin's docklands.
It was built by developer Bernard McNamara in 2006, with buyers paying as much as 750,000 euro (£550,000) for the properties.
But serious fire safety deficiencies were uncovered last year.
Dublin Docklands Development Authority, the nominal landlord, has so far paid 1m euro (£735,000) to fix the fire alarm system.
But further work is required to upgrade fire walls and smoke vents at a cost of 4m euro.
The docklands authority insists that is the responsibility of apartment owners as the company used by Mr NcNamara has gone into receivership.
The owners have been told they have to pay between 9,000 euro (£6,600) and 18,000 euro (£13,250) each.
They have said that while they could pay some of the cost, the authority still has responsibility for common areas.
Dublin City Council has warned that the buildings will be evacuated if a timescale for the work is not set out.
Gendsong, Mr McNamara's development company, has gone into liquidation.
Resident Paula Daly said she already pays a mortgage and maintenance fees and is not in a position to pay the money.
She told RTÉ: "We got hit with the news last night that they were looking for everybody to pay.
"I'm in a three bedroom duplex and they're looking for us to pay €18,000.
"I have two children and we both work and I just don't know where we're going to get the money to pay this."
Residents in an Irish apartment complex are facing a 4m euro (£2.95m) bill or possible evacuation over fire safety failings in their building.