The Auditor-General has found the Earthquake Commission has been inconsistent with its information and processes over the Canterbury earthquakes.
The report into how EQC has performed in managing the home-repair programme in Canterbury says that, overall, the Crown entity's performance is mixed.
The commission has repaired more than 40,000 homes at a cost of $1.5 billion from September 2010 until June this year.
The report says it took too long for repairs on the homes of vulnerable people, and homeowners have experienced long periods without specific information from EQC about their claim, leading to a lack of certainty while waiting for repairs.
It found that 20% of homeowners surveyed with repairs completed in 2013 were dissatisfied with the quality of the work.
Assistant Auditor-General Mike Scott said on Tuesday that recommendations to the EQC include a better provision of quality, timely information to homeowners.
He says the commission also needs to provide assurances over the quality of the repairs, and it needs to keep a close eye on its costs to ensure they are as reasonable as possible.
Mr Scott says the office will track the progress that EQC makes with the report's recommendations and will review the total programme costs when the home-repair programme is completed by the end of 2014.
EQC is responsible for repairing about 160,000 damaged homes in the South Island region. It will pay cash to settle about half of those and will manage the repairs of the rest.