Christchurch Hospital will gain four new wards as the Canterbury District Health Board responds to the region's earthquakes.
The board says the projects will address an urgent, short-term need for health service delivery.
It says the work is in addition to immediate repairs and earthquake strengthening, the cost of which is estimated at $70 million but expected to rise.
The new projects include a 36-bed acute assessment unit and a 10-bed surgical progressive care unit.
Two inpatient wards will be created, offering 53 beds. A temporary outpatient facility will be established.
At the Hillmorton site, the inpatient mental health service will be extended to four wards, each with a high dependency unit.
The board says the need for most of this work is a direct result of the Canterbury quakes.