Home sum insured

When you first take out home insurance, you’ll be asked to specify the total amount it would cost to rebuild your home. This includes the cost to rebuild your home to the same size, specifications, and quality.

This is known as your ‘total sum insured’. Your total sum insured is the maximum amount IAG, will pay in most cases, after any applicable excess has been deducted.

The Cotality Sum Sure calculator is an independent tool that can help you estimate the cover you need.

If you are an existing Co-operative Bank customer, you can review your sums insured at any time though your IAG insurance hub, accessed via the Open & Apply menu in our mobile app or internet banking.

Calculate sum insured

Once you enter your address, the calculator will automatically fill in basic details about your property. This provides a useful starting point for you to add any upgrades, renovations, or special features that may affect your insurance needs.

Keep in mind that the pre-filled information may not be entirely accurate for your specific home. It’s important to review the estimate carefully and adjust it based on your knowledge of your property—including any permanent structures like large sheds, pool houses, or garages.

The Cotality Sum Sure calculator uses average floor areas and standard building costs to provide a general estimate. If your home includes high-end finishes, unique architectural features, is unusually large, or has heritage value, the estimate may be too low. In these cases, consider seeking a more accurate estimate of the rebuilding costs from a registered property valuer or quantity surveyor.

Having trouble finding your address?

If you can’t find your address, and it includes a unit number e.g. 15a, try different variations such as 1/15 or 15/1.

If you still having trouble finding your address, it may be that the calculator does not have details of the property, it may be a new subdivision, or the calculator is not suitable for the property address.

Photos of your property

Don’t worry if the photo doesn’t match your house. The photo might be different because your house is new, or the photo is outdated, a boundary shot, or a street view. The property details are based on the address, not the photo.

Important information for Canterbury property owners

If you’re in the Canterbury area and your property has been identified as having a CERA technical category rating (foundation requirements), then an allowance will have been made for this. This is indicative only, and you should seek specific engineering advice for a reliable estimate of any costs.

Keep your total sum insured amount up to date

It’s your responsibility to set the total home sum insured when you apply for insurance. It’s important to regularly review your sums insured to make sure they’re up to date and that you have the right level of cover.

A good time to review your policy is when it comes up for renewal. It’s also a good idea to review your sums insured if you complete any renovations, as these may change how much it may cost to repair or rebuild your home after a loss.

Our insurance partner IAG, may adjust your sums insured at renewal to factor in rising building costs and changes in the market. However, these adjustments don’t account for your unique situation such as any changes you’ve made to your home since you last set your sums insured. Nor will these adjustments necessarily reflect the actual change to the replacement cost of your house.

If you set your total home sum insured too low, you may not be able to repair or rebuild to the same size and quality, or you could find yourself paying for some of the repairs or rebuild costs yourself, so that’s why it’s important to get it right.