Many renewals, particularly those from the middle of last year or earlier, have been spared the big rises, at least for now.
Others, once the EQC levy is added, have been made hundreds of dollars dearer - at times more than 50 per cent.
Two five-bedroom houses, in Remuera and Hamilton, saw their annual premium rise by more than $300.
Canterbury Property Investors Association president Kim Willems said the costs could be devastating for property owners.
"It's going to be quite a shock for people seeing those renewals."
Waikato Property Investors Association president Nancy Caiger said the big increases began late last year and had been compounded by the extra EQC levies showing up this month. "The earlier ones weren't so bad, but as they're coming in they've been getting higher and higher."
The new EQC levy applies to all insurance contracts that start next month or later.
The part of the levy that applies to housing insurance has gone up from $50 to $150, excluding GST, and for contents from $10 to $30.
Home Owners & Buyers Association president John Gray said that some homeowners had been forgoing insurance for the sake of putting food on the table and paying their mortgages instead.
APNZ