Around €35m is expected to be written off for the design and other work related to the abandoned plan to have the new National Children's Hospital at the Mater Hospital site.
John Pollock, project director for the National Paediatric Hospital Development Board, told the Public Accounts Committee that around €4m to €5m related to design fees.
Around €6m for the work can be saved as an asset.
The children's hospital will now be built on a site at St James's Hospital and is due to take its first patients in 2019.
The aim is to secure planning permission by December 2015 and for building work to begin in January 2016.
Around 2,300 staff will work at the new facility, which will have nearly 390 beds for patients.
The St James's site was chosen in November 2012 after initial plans for the Mater were rejected.
