Middlemore Hospital in South Auckland has been moving a large portion of its operations to a new $200 million clinical services building.
Facilities being moved this weekend include operating theatres, and the neonatal intensive and special-care units.
Counties Manukau District Health Board chief executive Geraint Martin said 28 babies in neonatal care will be carefully transferred on Sunday to the state-of-the-art units.
"What we have done is built a purpose-built link corridor from our maternity block into the clinical services block, which makes the journey very short and therefore greatly reduces the risk - but clearly we will be moving very, very carefully indeed."
The new neonatal facilities include an increased cot capacity of 38, highly specialised equipment, and a support area for parents and families.
The new hospital will have 13 operating theatres, two more than at present, which acting chief medical officer Wilbur Farmilo said represented a major increase in capacity.
He said state-of-the-art technology in the new building will help meet the needs of a growing population.
Mr Martin says the hospital does some of the most complex surgery around, and the new technology will ensure it can do things to a higher standard.
A special ducting system will ensure air pressure in the operating theatres is slightly higher than in the rest of the hospital, ensuring no air from outside comes into the sterile environment, reducing the infection risk.