Why you need to calculate your sum insured
When you take out a House Insurance policy you're responsible for confirming the amount it would cost to rebuild your house and to keep this figure up-to-date.
If your house is destroyed, for example by a storm or flood, it may be rebuilt up to your sum insured.
If your house is destroyed by a fire (except a natural hazard fire) you may be covered for up to 20% more than your sum insured.
In the case of damage caused by a natural hazard, Natural Hazard Cover (previously EQC) pays for a portion of the loss, and your house policy tops up to your sum insured.
Calculating your sum insured
Your sum insured isn't the same as the market value of your house. It’s the likely cost of rebuilding your home on its current site, based on:
Your current house
- size
- standard and type of construction
- structures, like decks, driveways, sheds, garages, retaining walls, fencing and outbuildings
- special features such as permanent swimming and spa pools
The cost to rebuild
- building material and labour costs
- demolition and removal of debris
- site preparation
- professional fees
- compliance costs
There are a number of ways you can calculate your sum insured - it's up to you. You can use the independent online Cordell Sum Sure calculator, or ask a licensed builder, quantity surveyor or a registered valuer to help.
Shared ownership
If you share a driveway or fences with your neighbours, you're responsible for insuring your portion of these.
If you live somewhere governed by a body corporate, like an apartment complex, the body corporate usually has one insurance policy covering all the units in the complex, and all the common property. This may already be insured on a sum insured basis – you can find out from your body corporate secretary or committee.
Please note that some insurers don't cover body corporates.
Cordell Sum Sure calculator
The Cordell Sum Sure calculator is an independent tool that generates an estimate of your likely rebuild cost based on the information you provide about your house. It may not be as accurate as a valuation by a professional. It's an estimate and isn't intended to replace a professional valuation of improvement replacement costs.
To use the calculator, enter your address and check the property details.
While the calculator can be useful it does have limitations. The estimated rebuild cost is generated without a physical inspection of your property. The data used may not take into account all relevant information. In addition, it may not be accurate for very large or high value homes, such as those that cost over $2 million to rebuild, nor does it factor in many special features including:
- areas of shared ownership, such as driveways and fencing that you co–own with neighbours
- hard to access sections
- houses with multiple construction materials (e.g. brick and weatherboard)
- houses with mixed commercial and residential use
- local laws and planning requirements.
Therefore, you might want to consider getting a professional valuation by a registered valuer, to ensure you’re adequately covered. If you don’t, you should consider adding an additional amount to your estimated sum insured to take any of the above limitations into account.
Remember to save a copy of your results for your own records.
Please see important information about the Cordell Sum Sure calculator.
Keeping your sum insured up to date
Once you’ve set your sum insured, it’ll be adjusted each year as part of the annual renewal of your policy.
The new sum insured amount will be included in your updated documents, which will be sent to you a few weeks before your policy is updated. You need to review the sum insured each year to make sure it’s still appropriate for your home. The Cordell Sum Sure calculator can help you with this.
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Important information
*Home Building Calculator
Cordell Sum Sure estimates the reconstruction cost of your home using information supplied by Cordell - Australia and New Zealand’s leading provider of building cost information. Cordell is a CoreLogic business. By providing information about your home, the calculator will provide an estimated reconstruction cost, including an allowance for professional fees, demolition, removal of debris and GST.
The Cordell Sum Sure calculator takes the answers you input (or confirm, as applicable) and analyses them against construction industry data collected by CoreLogic NZ Limited to generate an estimated reconstruction cost of the improvements on your property. Use of the Cordell Sum Sure calculator and any estimated reconstruction cost provided by it may not be appropriate for you and you will need to assess this given your knowledge of your property. A number of terms and conditions apply to the estimated reconstruction cost. Core Logic NZ Limited, Tower Limited (Tower) and Tower’s partners do not warrant the accuracy, currency or completeness of the estimated reconstruction cost and exclude liability for all loss or damage however arising (including through negligence) in connection with your use of the estimated reconstruction cost.
House Insurance provided by Tower Limited from 2 September 2024
Tower’s Quote to Buy tool has been developed and is operated by Tower Limited. Once you enter the Tower Quote to Buy tool, you will be a Tower Limited customer for the purposes of General Insurance. By using this Tower tool, you agree to the Tower Limited Terms and Conditions.
Tower Limited (also known as ‘Tower’) underwrites all contracts of House, Contents, Landlord, Car, Boat, Travel and Pet Insurance cover. Tower’s Travel and Pet Insurance is issued and managed by AWP Services New Zealand Limited trading as Allianz Partners. The contracts of insurance are between you and Tower Limited. Kiwibank Limited (Kiwibank) receives a commission from the sale of insurance policies sold by Tower when referred by Kiwibank. Kiwibank, or any member of the Kiwi Group Capital Limited (including Kiwibank) group of companies, does not guarantee the obligations of, or any products issued by, Tower Limited and is not liable if Tower (or other insurer of the policy) declines to pay a claim. Any claims issues are between the insured person(s) and Tower Limited or any involved third party. Full terms, conditions and exclusions are available in the applicable policy wording. View Tower’s financial strength rating and solvency margin on their website at tower.co.nz.
Kiwibank doesn't provide financial advice for insurance and is not engaged by Tower Limited to provide any financial advice in respect of its insurance products. Terms and conditions, exclusions, limits and sub limits apply. Insurance cover is subject to Tower’s current acceptance underwriting criteria.
Kiwibank Limited holds no responsibility for the content on third party websites and make no representations as to the accuracy of the information provided on those websites.
Previous insurance policies administered by Ando and Tower
- House, Contents and Car Insurance administered by Ando
- House, Contents and Car Insurance issued by Tower Limited before 5 April 2018.
If you're an existing policy holder you can find the relevant information about these policies on our products no longer offered page or our legal documents archive page.