The National Maternity Hospital will double in size when it relocates to the campus of St Vincent's University under a €150m initiative.
Details of the move in five years were announced yesterday, with Dr Rhona Mahony, Master of the hospital, saying that Holles Street is "no longer fit for purpose".
The hospital is one of the busiest maternity units in Europe, and one in eight of all Irish babies are born there.
Announcing the development, Health Minister James Reilly said: "This new hospital will be twice the area of the existing facility and will be purpose-built to a high spec." Building work is scheduled to start in the second quarter of 2016, and the new hospital is scheduled to be finished no later than the end of 2018, he said.
Of the existing historic building, parts of which date back to the mid-1700s, Dr Mahony said that the building is owned in trust by the governors of the hospital.
She said that there is an agreement in principle that, on receipt of a world-class facility, "we are happy to cede this building to the State".
Accommodation at the new hospital will include a high-dependency unit, a neonatal care unit and a special care baby unit. Ante- and post-natal care will be provided in mostly single, en-suite rooms.
"We have at the moment 180 beds. We will be getting 230 beds in the new facility," Dr Mahony said.
Dr Mahony said that there will be some upgrading of current facilities from September, as the relocation is not taking place for five years.
The neonatal unit is set to be refurbished, and the HSE has already provided money for that to go ahead.
Some €150m has been approved in the HSE's Capital Plan to allow the ambitious project to proceed.