House Insurance Calculator
With construction costs unstable, make sure your rebuild cost is fully insured - our guide explains everything you need to know.
Updated 3 September 2025
Estimating the rebuild cost of your home is essential for house insurance policies
Related resources: Our trusted go-to guides for Insuring an Old House and Difficult Areas for House Insurance explain what you need to know should either of these issues apply to you.
- Insurers ask for a ‘sum insured’ which is the highest amount that will be paid out if a house is damaged beyond repair.
- Insure for too low, and you could be out of pocket. Insure too high, and you are overpaying on your insurance policy.
- Because sum insured is based on today's building costs, how much you paid for your house, its rateable value or current QV.co.nz estimate is irrelevant.
- House building costs generally increase every year due to inflation, and more so since 2020 per this RNZ article from 2022. This means you will need to make sure your sum insured is accurate. If you have recently renovated or extended, it's likely your sum insured value will need to be increased.
Related resources: Our trusted go-to guides for Insuring an Old House and Difficult Areas for House Insurance explain what you need to know should either of these issues apply to you.
Why calculate your home's rebuild cost?
How Much Should I Insure My House For?
In the video below, MoneyHub Founder Christopher Walsh explains how house insurance calculators work and why you must ensure you have enough coverage every time you renew or switch insurers:
- If your house is damaged or destroyed, you need to make sure you have the right level of house insurance cover.
- If you have too little, you won't be able to rebuild or repair your home without being out of pocket.
- House insurance policies require you to estimate the cost of rebuilding your house, also known as the 'sum insured' value. This is maximum your insurer will pay out to repair or rebuild your home if it is damaged or destroyed.
How Much Should I Insure My House For?
In the video below, MoneyHub Founder Christopher Walsh explains how house insurance calculators work and why you must ensure you have enough coverage every time you renew or switch insurers:
Compare House Insurance Quotes With Our Three Trusted Insurers - MAS, Tower and Initio
As a background, there are two fundamentally different types of house insurance:
1) Area Replacement (offered by MAS) - This pays the actual cost to rebuild, no matter what:
2) Sum Insured (Tower, Initio, others) - Pays up to the amount you estimate, nothing more
The Uncomfortable Truth: Many New Zealand homeowners have sum insured and are unknowingly carrying a six-figure liability. They're saving $20-$30/month but risk losing $200,000+ if disaster strikes and building costs spike further. Our guide to Area Replacement vs Sum Insured explains more.
Get All Three Quotes - Know Your Real Options with Trusted Benefit-Focused Insurers:
- Our detailed analysis across multiple home insurers identified MAS, Tower and Initio as leaders for different coverage needs.
- MAS offers the only mainstream area replacement coverage - paying full rebuild costs even if they spike 40%+, while Tower and Initio deliver market-leading sum insured options with competitive pricing.
As a background, there are two fundamentally different types of house insurance:
1) Area Replacement (offered by MAS) - This pays the actual cost to rebuild, no matter what:
- Building costs spike 40% after a disaster? Covered.
- Your villa needs heritage materials? Covered.
- Construction inflation runs wild? Still covered.
- Real example: 200sqm house, North Shore Auckland = $290/month for FULL rebuild protection per an MAS estimate
2) Sum Insured (Tower, Initio, others) - Pays up to the amount you estimate, nothing more
- You estimate $600,000, and the rebuild costs $750,000 - you pay the $150,000 difference
- Unaware of inflation in building materials? You're underinsured
- Disaster strikes before your annual review, and your sum insured is too low? This is bad news
The Uncomfortable Truth: Many New Zealand homeowners have sum insured and are unknowingly carrying a six-figure liability. They're saving $20-$30/month but risk losing $200,000+ if disaster strikes and building costs spike further. Our guide to Area Replacement vs Sum Insured explains more.
Get All Three Quotes - Know Your Real Options with Trusted Benefit-Focused Insurers:
- Get a MAS Area Replacement Estimate (1-2 Minutes): Full rebuild protection regardless of cost spikes
- Get a Tower Sum Insured Quote (1-2 Minutes): Market-leading pricing with comprehensive benefits for sum insured coverage
- Get an Initio Sum Insured Quote (1-2 Minutes): Instant quotes even for difficult properties with transparent pricing
Why We Don't Compare MAS Prices in Our Tables: MAS uses area replacement - you're buying unlimited rebuild protection. Tower and Initio use sum insured - you're buying a fixed dollar amount of coverage. Comparing their prices is like comparing unlimited data plans with 10GB plans - they're fundamentally different products. Our tables show sum insured options only. For area replacement pricing, get a MAS estimate directly.
For Sum Insured Options: Tower and Initio consistently deliver the best combination of price and comprehensive benefits. Both offer excellent coverage within the sum insured model - just remember you're still carrying the rebuild cost risk.
MoneyHub's Position: After Christchurch showed us 40% building cost spikes, and with climate events becoming routine, area replacement isn't "premium" insurance - it's actual insurance. Sum insured makes you the insurer of last resort, and while area replacement may cost 10-20% more, we believe that insurance that leaves you $200,000 short isn't good value at any price.
The cheapest insurance can be expensive if it doesn't cover the cost of rebuilding. The best insurance - the kind that actually protects your biggest asset - is worth every cent.
Compare all three today - the 3-6 minutes it takes could save you $200,000 tomorrow - visit MAS, Tower and Initio to see live quotes from trusted insurers.
For Sum Insured Options: Tower and Initio consistently deliver the best combination of price and comprehensive benefits. Both offer excellent coverage within the sum insured model - just remember you're still carrying the rebuild cost risk.
MoneyHub's Position: After Christchurch showed us 40% building cost spikes, and with climate events becoming routine, area replacement isn't "premium" insurance - it's actual insurance. Sum insured makes you the insurer of last resort, and while area replacement may cost 10-20% more, we believe that insurance that leaves you $200,000 short isn't good value at any price.
The cheapest insurance can be expensive if it doesn't cover the cost of rebuilding. The best insurance - the kind that actually protects your biggest asset - is worth every cent.
Compare all three today - the 3-6 minutes it takes could save you $200,000 tomorrow - visit MAS, Tower and Initio to see live quotes from trusted insurers.
House Insurance Calculator - Frequently Asked Questions
We have listed popular FAQs to help you understand the importance of 'sum insured' and why you need it to be accurate and reflective of your total rebuild cost.
Can my home insurer calculate my 'sum insured' or home replacement value?
No - it is the responsibility of the insurance policyholder to estimate their sum insured value. Every house is different, and for this reason, no insurer can estimate or provide direction for how much your house would cost to rebuild.
Is the home insurance calculator accurate?
The online calculator is provided by Cordell, New Zealand's leader in building replacement cost calculators. Cordell has a wealth of experience in overseas markets, and brings its technology to New Zealand, which is free to use.
The Cordell Sum Sure Calculator is used by thousands of people every year from all over New Zealand. While accuracy is at the heart of every calculation, the Cordell Online Sum Insured calculator does not consider every possible feature of a home. You are asked to specify any special features or additions your home has to make the quote more accurate. The true cost of replacing your home will depend on the specific details of your home.
Please note, the Cordell Online Calculator does not provide advice, it is merely an estimate, and you can choose to rely on it, or not.
The Cordell Sum Sure Calculator is used by thousands of people every year from all over New Zealand. While accuracy is at the heart of every calculation, the Cordell Online Sum Insured calculator does not consider every possible feature of a home. You are asked to specify any special features or additions your home has to make the quote more accurate. The true cost of replacing your home will depend on the specific details of your home.
Please note, the Cordell Online Calculator does not provide advice, it is merely an estimate, and you can choose to rely on it, or not.
What are the limitations of the house insurance calculator?
While the Cordell Online Calculator can estimate your sum insured, it won't be able to take into account 'special features' which can alter the cost of rebuilding. These include:
Be aware: if your sum insured does not cover all your potential costs, you could end up paying for them yourself.
- Added costs if your house is built on an uneven section or steep slope
- High-end luxury fittings
- Building consents for high-end properties
- Added costs involved with building in unique locations
Be aware: if your sum insured does not cover all your potential costs, you could end up paying for them yourself.
Other than the online calculator, how else can I estimate my home's sum insured value?
Beyond the calculator linked on this page, you can also contact a builder, architect, quantity surveyor or a property valuer. Please be aware that you are not insuring for the value of the land, just the rebuilding costs. In cities like Auckland and Tauranga, and locations like Queenstown, where land prices are relatively higher than other cities in New Zealand, your sum insured may be as low as 60% of your property value. For example, a $1m home in Auckland may have a sum insured value of $550,000, due to the high value of the land.
7 things to consider when comparing home insurance policies:
- Index-linked cover - building costs go up over time; does the covered amount increase with inflation to meet the predicted costs of rebuilding later on?
- Temporary and alternative accommodation - if you can't live in your home due to a fire, flood or earthquake etc, does the policy compensate you for the costs of finding another place to live (i.e. rental and bond costs).
- Excess - often overlooked, how much can you afford in cash if you need to make a claim? As a rule, the lower the excess, the higher the insurance cost.
- Water damage - does your policy cover damage caused by burst pipes or accidental flooding?
- Home Emergency Services - some insurance policies include cover for heating and plumbing repairs along with other home emergencies as part of their standard policy. But others do not, or offer it as an optional extra.
- No claims discount - what will the premium cost when you renew if you don't make any claims?
- Different cover for different policies - our guide to home insurance indicates there is a range in benefits offered by home insurers. Make sure you understand where there are differences, and if they affect you.
Know This: Some areas within New Zealand are problematic to insure. Initio Insurance offers instant assessments of any risks - all you need is to enter your address to dive deep into Initio's unmatched property data. If you're a homeowner or potential buyer, Initio enlightens you about your options and tells you if there is a cause of concern (like flood risk).
MoneyHub Founder Christopher Walsh Explains How Our Friends at Initio Offer Instant Quotes Based on Your Address:
Christopher Walsh
MoneyHub Founder |
|
|
