Maintaining the facade of the Earlsfort Terrace building, a new 2,000-seat auditorium will form the centrepiece of the project.
The existing hall will be converted into a 900-seat mid-sized space, with an additional 400-seat space also on site.
Announced yesterday, the plan, which is at an early stage, will also incorporate a restaurant for pre-concert dining and will open up the Iveagh Gardens at the back of the NCH.
The plans, which NCH director Judith Woodworth described as “aspirations of the NCH board”, have not yet received the backing of Government, but there is a commitment to develop the NCH in the Programme for Government.
Ms Woodworth said that “precise plans are not drawn up yet” and they “would be arrived at through an international competition”.
She added it was not yet clear where funding would come from, but it would cost about €40m to buy the seven-acre site, being vacated by departments of UCD, and €100m to redevelop.
“The Department of Arts are very supportive of our vision to develop the site,” Ms Woodworth said.
She said she did not see the NCH moving to another site during construction. The plan was to build a new hall and move into that while the current hall is redeveloped, she said.
The NCH opened on the current site in 1981 and occupies the building that formerly housed UCD, before it moved to Belfield in the 1960s.
However, while welcoming the announcement of plans for bigger performance spaces at the NCH, some opera and music producers are qualified in their support for the NCH proposals.
Andrew McLellan, artistic director of Opera Theatre Company, said: “There should be more money for productions to build audiences for quality work.”
Mr McLellan welcomed the plan to build a small 400-seat and mid-sized venue in Dublin city centre, however, saying it would give companies like his the opportunity to stage productions in the more accessible city centre, rather than in The Helix concert hall on the city’s north side.
The announcement comes in the week the NCH published good financial results for 2004. In all, 396 events were staged last year with about 280,000 people attending the NCH last year.
Turnover last year was almost €5m, and indications are good for this year, Ms Woodworth said.