A Consumer NZ survey of house and contents insurance this year found homeowners could save up to $1000 a year by switching companies.
Consumer chief executive Sue Chetwin said insurance premiums had been steadily rising since the Christchurch earthquakes and putting pressure on household budgets.
"Switching insurers is one way consumers can ease the financial pain," she said.
Statistics NZ data show weekly household expenditure on all insurances rose 20 per cent in the three years to 2013. But spending on house insurance increased by 38 per cent during the period.
The latest Consumer Price Index shows premiums are up again. The cost of house insurance rose three per cent in the year to June 2015, well ahead of the 0.3 per cent rise in general inflation.
"House insurance is a necessity in our shaky isles. But if you haven't reviewed your cover for a while, then it's well worth doing. Many people will be able to save money on their premiums, without sacrificing the extent of their cover. Our research has found the savings can be hundreds of dollars a year," Chetwin said.
If you're shopping around for insurance, Consumer NZ recommends getting at least two to three quotes from different companies to compare how they stack up.
Chetwin encouraged consumers to negotiate with their insurer if the premiums they were paying weren't competitive. "If you rarely make claims and your premiums have increased, ask your insurer for a better deal before walking away."
You can also reduce premiums by taking a higher excess.
The excess is the amount of each claim you must pay yourself. It's usually around $400 for house insurance but Consumer NZ found taking a $1000 excess can cut premiums almost in half with some companies.
Other discounts may be available. If you have your house and contents insurance with the same insurer, you should get a discount, Chetwin said.
Some insurers also offer discounts if you have a security alarm installed or if you're aged 50 and over.
CONSUMER NZ'S TIPS FOR HOUSE INSURANCE:
Shop around. Select at least two insurers and ring them for quotes.
Get full details of the policies you're considering and make sure they have suitable cover for your situation.
Check the fine print about cover for different types of natural disasters.
Ring your existing company. If it doesn't offer the best deal, say what you've been offered and ask them to go one better. It's surprising how often this works.