Work is under way to restore power and phone lines to the HSE southern headquarters after an arson attack badly damaged the building over the weekend.
However, it is likely to be Wednesday before services are back.
Upwards of 190 staff reported for work at the farm centre building this morning and have been relocated to HSE offices in the area.
Customer care and general phone inquiry phone lines are back in operation.
Meanwhile, the man in his 40s who was questioned by gardaí about the arson attack has been released without charge.
A file is to be sent to the Director of Public Prosecutions.
