Christchurch Hospital will begin urgent work on Tuesday to provide back-up to its steam system threatened by earthquake damage.
The steam supply is vital for sterilisation and general heating, but the pipes are under subsiding streets.
Work has begun to connect six diesel generators as a back-up.
Hospital staff say they are unlikely ever again to put acutely unwell patients on upper floors that are hard to evacuate.
About 100 bed-ridden patients were carried or dragged on mattresses down stairs from the top two floors of the main inpatient acute wing on the night of the February quake.
Canterbury District Health Board says it will change the use of the top floors.
Support package for family GPs
The health board says it is working on a support package for family doctors who are back at work but lack patients in some of the most hard-hit parts of Christchurch.
Some doctors in areas such as Aranui say many patients have left for other parts of New Zealand or Australia, and it is not clear when they will return.
Health board chief executive David Meates says there are vulnerable practices and it will support some GPs with a package to ensure they will continue to be viable businesses.