About 800 Ministry of Health staff will move back into their Wellington head office after a $24 million renovation.
The project was in the news in March after a Ministry forecasting error led to an $18 million budget shortfall.
The ministry budgeted $24 million dollars for the refit in 2014, but later had to ask the government for an extra $18m after what it called a financial forecasting error.
The ministry's lease on the building at 133 Molesworth Street expired at the end of 2014 and the building needed earthquake strengthening and an extensive refit.
A spokesperson said that had been completed ahead of schedule and within budget.
It said the $18 million shortfall was covered by a leasing agreement and no government top-up was needed to complete the project.
Staff spread across five buildings in the capital would move back into the head office by 21 November, the spokesperson said.