The Insurance Council says policy cover may drop and premiums rise in the wake of the Canterbury earthquakes.
Consumer New Zealand says premiums have already risen by 10% and could go even higher.
The Government has already announced it will double the EQC component of insurance premiums because of the February earthquake.
The Fire Service tax component will also rise, along with the cost from implementing new regulations imposed on the sector by the Reserve Bank.
In addition, reinsurance costs are rising as are the price of materials and labour to repair Christchurch.
Insurance Council chief executive Chris Ryan says that adds up to an increase in premiums, although he is reluctant to name a percentage.
He says reinsurers may also limit the amount of cover insurance companies can offer - such as covering 80% of the cost if a house is destroyed instead of 100%.
Mr Ryan says insurers will be talking to reinsurers to try avoid that scenario.
Consumer New Zealand has canvassed the cost of premiums and says there have already been significant increases.
Chief executive Sue Chetwin says Westpac has increased some premiums by 30% because of a high number of claims, escalating building costs and the cost of the earthquake.
Ms Chetwin says by most companies will have a better idea of the impact of the earthquakes by July.