Housing New Zealand will have to find $30 million in order to cover its insurance excess costs for earthquake claims.
The corporation owns more than 6000 properties in Christchurch and about three quarters of them have suffered quake damage.
In a briefing to the Minister of Housing, it says claims worth more than $320 million have been made for the September 2010, and February and June 2011 earthquakes, and each event carries a $10 million policy excess.
It says the $30 million excess will be treated as a cash loss.
The unknown cost of land remediation and silt removal will also have to be met because they are not covered by insurance.
Housing New Zealand says 175 of its homes are uninhabitable and 25 of those are beyond repair.