Home Insurance Sum Insured

Knowing the total cost to rebuild your home can be difficult. So, we’ve put some information together to give you a better idea of exactly what your sum insured is, and how to calculate it.

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What is your sum insured?

When you first take out Home Insurance with ASB, we’ll ask you to specify the total amount you would need to rebuild your home to the same quality – this is your sum insured. Your sum insured is made up of your home sum insured, plus the sum insured for any special features you buy cover for. It’s the maximum amount to be paid, after any applicable excess, if your house was wiped out by a natural disaster or suffered significant damage from major events, like flooding or fire. It not only needs to cover materials and labour, but other costs to rebuild your home like demolition, consents and other fees.


What sum insured is:

  • The estimated maximum amount it would cost to repair or rebuild your home if it was destroyed, including recreational features, retaining walls and special features.
  • An amount that covers materials and labour as well as costs like demolition, consents and other fees. 
  • An amount you need to choose.

What sum insured isn't:

  • It's not the rateable value (RV) or capital value (CV) of your home. 
  • The market value or the price you paid for your home.
  • It's not the value of the land.  
  • It's not automatically inclusive of special features (such as a bridge, jetty or cable car) on your property - you may need additional cover for these. 

Getting your sum insured right

If your sum insured is too low, you may not be able to repair or rebuild your home to the same size and quality. Or, you could find yourself paying for some of the repairs or rebuild yourself. So, it’s really important to get it right.

Working out your sum insured

The good news is there are several options to help you decide. Your sum insured should include:

  • Demolition costs

  • Council consents and other professional fees

  • Labour costs

  • The floor area of your home

  • Fixed floor coverings (like carpet)

  • Land slope

  • Construction materials

  • Quality of materials and finish

  • Fixtures and fittings (i.e. baths, toilets, ovens, heat pumps)

  • Number of levels

  • Your home's design: villa, bungalow, contemporary and one-off architectural

  • Outbuildings such as detached garages and carports, granny flats

  • Driveways, decks, paths and fences

Make sure you include recreational features (such as swimming pools and tennis courts), retaining walls or special features (such as bridges, cable cars, jetties) that might not automatically be covered. It's important to check your policy wording to understand the applicable policy limits and exclusions and where you might need to add extra cover so you aren't under insured.

Calculating your sum insured

Use an online calculator

The Cordell Sum Sure calculator is free, easy-to-use and takes only a short time to complete. All you need to do is enter your address to generate an estimated cost for rebuilding your home. Check the information the calculator has provided, if anything isn’t quite right, you can make changes to get a more accurate estimate.

The figure is based on information gathered throughout New Zealand from third party organisations, such as your local council. The calculator takes into consideration anticipated construction costs, allowances for professional fees, demolition, removal of debris and GST.  

Remember, the estimated figure produced by the calculator is a guide only. It also doesn’t take into consideration future changes to building costs (i.e. inflation) over your policy period so if you want to include an allowance for this in your sum insured, you’ll need to add it to the estimate generated by the calculator. The calculator includes professional fees, demolition, removal of debris and GST and will account for price difference in some of these services around New Zealand.

Calculate your sum insured

Ask a professional

If you want more peace of mind that your sum insured is accurate, it may be useful for you to get a professional to assess your property. This is strongly recommended for homes over 500sqm, over $1.5m in rebuild costs or architecturally designed homes. In these instances you may want to consult a registered quantity surveyor or registered valuer for professional advice on an estimate to rebuild your house:

More about Cordell Sum Sure

  • If your address can’t be found and it includes a unit number (e.g. 23a), try different variations (e.g. 1/23, 23/1). If your address still can’t be found, Cordell Sum Sure calculator may not have details of the property, it may be a new subdivision, or the calculator is not suitable for the property at that address.
  • Don’t worry if the photograph doesn’t match your house. The photograph might be different (e.g. your house is brand new, or there is an old photo, a boundary photo or street front photo) but the property details are based on the address not the photo.
  • The calculator assumes an average floor area for any garages, sheds or pool houses, so if you have a particularly large detached building you might want to select a sum insured higher than the estimate the calculator provides.
  • 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.
  • The calculator uses typical building costs for standard finishes to provide an estimate. If your home has significant special features and fittings, was built to a superior standard, is very large or has a high value, consider using other options to establish a better estimate of the rebuilding cost, such as a registered property valuer, or quantity surveyor, or select a sum insured higher than the estimate the calculator provides.
  • Factors such as the slope (steepness) of your land, the style and quality of construction are important to get right when using the calculator. It’s a good idea to ask for advice if you’re unsure what to enter in the calculator.
  • This calculator has been customised for ASB, so it’s important that you use the calculator provided by your insurer. The ASB Cordell Sum Sure calculator adds GST to the estimate it produces because your ASB sum insured is an amount which needs to include GST.

More about shared ownership

Owners of cross-leased properties need to consider how to cover shared assets such as driveways, fences and retaining walls. Check your property's Title documents for reference to a 'plan of flats' (or similar) that sets out the various areas the cross lease applies to and if you're still unsure, talk to your legal advisor.

Things to note

This calculator provides an estimated sum insured for your home but the final decision is yours. If you think your amount is not correct, you can change it. This is general information and is not a recommendation, opinion or guidance.  If you would like a recommendation, please contact a registered valuer or quantity surveyor. This calculator information does not provide any advice or opinion on the extent or adequacy of the cover provided by sum insured insurance. This information is not financial advice and does not take into account your particular situation. You must make your own decision on the sum insured that is appropriate for your circumstances.

The Cordell Sum Sure calculator is an independent tool. ASB does not have access to the information you enter, or access to the estimate that it produces. So, if you’d like to adjust your home’s sum insured, or add additional cover for retaining walls, recreational features or special features, you’ll need to contact us. It’s your responsibility to ensure that your sum insured is adequate.

Get started

1. Calculate

Find out how much it would cost to rebuild your home.

Calculate now

2. Quote or update

Call 0800 200 252 or come into any ASB branch and we’ll provide a personalised quote or update your existing policy.

3. Decide

Accept the quote and we'll get your insurance put in place, or confirm the changes to your policy.

4. Update

Tell us if something changes that affects your home insurance.

The availability of insurance cover is subject to your application being approved. Exclusions apply. For full details, refer to the Policy Document which is available from ASB Bank Limited. This insurance is underwritten by IAG New Zealand Limited. See further information regarding IAG's financial strength rating. The calculator is provided by Cordell, a CoreLogic business. Your use of the Cordell Sum Sure calculator is authorised on the condition that CoreLogic, ASB and IAG New Zealand Limited (and their related companies) do not warrant the accuracy, currency or completeness of the estimated reconstruction cost and do not have any liability of any kind for any loss or damage howsoever arising (including through negligence) in connection with your use of the Cordell Sum Sure calculator.