Canterbury District Health Board has defended its planning as rising patient numbers put Christchurch Hospital under extreme pressure.
DHB chief executive David Meates says in the past four years, patient numbers have risen from 89,000 per year to more than 102,000 - an increase of 14% - due to an aging population and the greater level of care required.
Mr Meates says new facilities are planned but they will not be ready until about 2016.
He believes the hospital has handled the situation well and the DHB has acted prudently in planning new multimillion-dollar facilities on a congested site.
Mr Meates says short-term solutions include liaising more with community care and shortening hospital stays.
Patient lobby group Health Cuts Hurt says while funding is often a problem for health services, the shortage of space at Christchurch Hospital has been discussed for some years.
The group says it is frustrating that solutions cannot be found more quickly.