The final two blocks of apartments at the site of the former Priory Hall complex will not be completed by next month as planned.
Dublin City Council (DCC) has blamed the coronavirus lockdown for delaying the completion date for the buildings, which will house 20 apartments.
The council has also said it can't say what the overall net cost of rebuilding the complex will be. It was previously put at €50m - 10 times an original estimate.
Eighteen of the 20 apartment block have been completed.
Originally developed by disgraced developer Tom McFeely, notoriety descended on the complex in 2011 when 256 residents had to be evacuated on the orders of the High Court due to fire safety issues.
Rebuilding work was then carried out by DCC and funded by the Department of Housing, with the new development named New Priory.
According to the council, there will be 188 residential units in the rebuilt development and four retail units.
There are 26 buy-to-rent units which have been returned to their owners.
Another 127 units have been sold or will be sold, with 63 currently being sold.
"To date sales have been agreed on 33 of these units," the council said.
"The remaining 35 units are for social housing. It is not possible at this stage to give a final accurate figure as to what the net cost of rebuilding Priory Hall will be."
The council said without Government intervention the complex "would likely still be lying vacant and derelict".
Apartments have been on sale from €240,000 to €300,000 in phase two of the project.