The £150 million Royal Hospital for Children and Young People (RHCYP) was first due to open in winter 2012, but has faced a decade of delays.
Construction on the RHCYP was due to be finally completed on January 25, but it has been further put back by “two to three weeks” due to pressures associated with Covid-19.
NHS Lothian said the virus had presented “a number of challenges” to the construction work in protecting the health and safety of those on and off site.
A scheduled opening date of November 23 last year had already been cancelled due to the virus.
It comes as NHS Lothian announced the move of the Child and Adolescent Mental Health Service (CAMHS) to the new site on Friday, which it said will be unaffected by the delay.
Around three-quarters of outpatient services are currently housed at the new site at the Edinburgh BioQarter, while the Emergency Department remains in the old site at Sciennes.
Susan Goldsmith, Finance Director and Executive Lead for the Project, NHS Lothian, said: “Covid-19 has presented a number of challenges for everyone involved in the project to complete the remedial and enhancement works at the Royal Hospital for Children and Young People.
“Our teams have done an incredible job to drive the project, but because of the necessity to protect the health and safety of all of those on and off site, we are anticipating that the timeline will currently have to shift by two to three weeks. This does not cause a difficulty as we have a phased implementation plan which can take account of this shift. This plan has already seen a number of children’s services move in, including the Children’s and Adolescent Mental Health Services (CAMHS) which transferred into their new home today.
“Handover will be followed by a commissioning period before the final migration of the remaining Children’s Services. The commissioning period, which is standard in any new building of this scale, allows for final checks, the installation and testing of equipment and staff training.”