A NHSGGC spokeswoman said the health board was now “confident of the water quality in the ward”, however the ventilation system did not fully comply with NHS guidance.
She said exemptions were previously agreed in 2017 and ongoing risk mitigations continue to be applied as the ward remains open.
The spokeswoman added: “Patient safety remains central to everything we do.
“Due to ongoing infrastructure defects, we have closed a number of rooms in recent weeks to undertake both planned refurbishment as well as responding to a number of defects.”
The health board said it was “necessary” to develop a proposal for a new unit which would be more resilient, fully compliant with legal guidance and provide greater patient, staff and public confidence.
“This project will take significant time and investment. However, we are now commencing this important work,” the spokeswoman added.
“In the meantime, we continue to assess and take actions as necessary to maintain this vital national service.”