Would be home-buyers are being urged to check the insurability of properties before signing a binding purchase agreement in the wake of a series of major storm events this year.

While one-off floods do not typically affect whether a property will get insurance, multiple events may mean insurers won't cover certain events or could push up the excess to higher levels.

Tim Grafton, chief executive of the Insurance Council of New Zealand, said some properties in Kaeo in Northland were not covered for floods because the risk was so high.

A group of houses in Christchurch's Flockton Basin faced an excess of $10,000 per flood before the council undertook a $48 million flood mitigation programme.

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Parts of Thames and the Coromandel also struggled to get flood insurance cover, Grafton said.

Sea levels rising and coastal erosion were also issues people needed to consider.

Grafton said residents of the small coastal town of Haumoana in southern Hawke's Bay found it difficult to get insurance at all because of coastal erosion problems.

According to Wikipedia the shoreline at Haumoana is retreating at an average of between 0.3m and 0.7m per year.

"If you are buying a property you would be nuts to put in a binding offer without checking you can insure it."

Grafton said people who could not get insurance for a property would also struggle to get a mortgage.

"If you can't get insurance the bank won't loan you the money."

Grafton also said those considering paying top dollar for prime coastal properties should think about future erosion issues.

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Rising sea levels and coastal erosion could impact properties that were selling for premium prices on today's market.

He said properties which faced flooding or erosion problems in years to come may be harder to get a longer-term mortgage on.

If the term became shorter the payments would increase which would also limit who could afford to buy the property in the future.

When demand, reduced the price of resale could also fall, he said.

Grafton urged people to check out land information memorandums provided by councils for properties to understand what natural hazards the property could face.

But he said each insurer followed its own rules of thumb.

Brendan McGillicuddy, national portfolio manager home for IAG, the country's largest insurer, said it relied on council hazard zoning to help define areas that present risk - such as locations presenting risk of erosion and being susceptible to big storm events.

But all policies were assessed on a case-by-case basis.

"IAG does not adhere to location-specific blanket exclusions that prevent homes across whole towns or areas from being eligible for home or contents cover."

McGillicuddy said that while beachfront properties in certain locations may fall within a council hazard zone, some locations such as Haumoana also had homes out of this zone.

"...so cover may still be offered but may be subject to premiums loadings, higher excesses and other special terms like market value cover only, exclude damage from sea water, storm surge or inundation."

A spokeswoman for AA Insurance said it offered home and contents cover throughout New Zealand except for a period of time after a significant event, such as home cover after the earthquakes in Canterbury and Kaikoura, and the flooding in Edgecumbe.