The new chairperson of the development board established to build the new national children's hospital has said that there are no savings to be made that will significantly affect the headline cost of the new facility.

Fred Barry said the challenge over the next few years will be to contain any growth in the €1.4bn projected cost.

Mr Barry told the Oireachtas Health Committee there was late recognition of the scope of work and what it would cost to build the hospital.

He said that there was an underestimate of the scope of the project at a very early stage, compounded by initial tender documents for construction which did not properly pick up the full scope.

Mr Barry said that the challenge now is to build the hospital, with thousands of people working there on a very constrained site.

He said he did not believe it would be good business to re-tender the project and said it would take one-and-a-half to two years to get a new contra-contract and there would be extra costs.

Mr Barry said the PwC report on the project was due in a matter of weeks and he was looking forward to reading it.

Mr Barry was recently appointed chair-designate to the board after the resignation of former chairperson, Tom Costello, in the wake of the controversy over cost overruns.

He is a chartered engineer and was group managing director for Ireland and the UK for the engineering company Jacobs.

He was also chief executive of the National Roads Authority.

Mr Barry said that the two-stage process for building projects is relatively new to Ireland but very common around the world.

He said there was nothing wrong with the two stage process and it had lots of benefits, including getting work started early.

Mr Barry said it can work well but that did not mean it worked well in this instance.

Fine Gael TD Bernard Durkan said the did not understand the need for 6,000 rooms in the new hospital.

He asked if there would be a benefit in reducing the number of rooms, once it did not undermine the overall thrust of the facility.

Mr Durcan said that if the project were to stall it would be a national disaster.

He said the hospital was needed and should have been built 20 years ago.

Mr Barry said that the idea of moving to a new location for the new children's hospital should be put from people's minds and told the committee that if the facility is to be delivered it needs to be built where it is.

He said the number of rooms necessary have been determined and the hospital has fire certs.

Mr Barry told the committee that if the board starts forecasting costs rising above €1.43 billion, this will be flagged immediately to everyone else involved.