Floor area
Check plans, council records or a professional measurement. Add all levels and verify how garages, decks and verandahs are treated.
New Zealand · Rebuild cost and sum insured
Home insurance calculator NZ
Estimate a rebuild sum insured from your own property figures, see every cost in the calculation, and compare it with the cover shown on your policy schedule.
No address required · No contact details · Not connected to any insurer
Planning sum insured
$840,000
The component estimate is $836,000. The displayed planning amount rounds up to the next $10,000.
Main building
$600,000
Other entered costs
$160,000
Estimate breakdown
- 150 m² × $4,000/m²
- $600,000
- Demolition and clearance
- $40,000
- Professional and council fees
- $70,000
- Garages and other buildings
- $30,000
- Outdoor and special features
- $20,000
- Difficult site or access
- $0
- Contingency · 10%
- $76,000
Current cover check
Possible gap: $140,000
Your current $700,000 is below this planning amount. Recheck every input, then discuss any change with your insurer or adviser.
Planning estimate only: this is not an insurance valuation, premium quote or guarantee of a claim payment. Check whether every figure includes GST and whether your policy treats special features separately.
This calculates cover, not price: your premium depends on the property address, natural-hazard risk, construction, claims, excess, benefits and insurer pricing. Request current quotes after checking the rebuild amount.
Find the right figure for each field
The calculator is most useful when each input comes from a named source. Keep the rebuild report, valuation or quote with your policy records so you can repeat the check at renewal.
Rebuild rate
Use a current insurer-approved calculator or professional estimate. Do not substitute the sale price, council value or land value.
Extra structures
List detached garages, sheds, driveways, pools, solar equipment and retaining walls, then check which items have policy sub-limits.
Fees and site work
Confirm demolition, debris removal, design, engineering, consents, GST, slope and access costs instead of assuming the square-metre rate includes them.
How the home insurance calculation works
The main-building estimate is floor area multiplied by the rebuild rate you enter. The calculator adds demolition, professional fees, outbuildings, outdoor features and any site allowance, then applies your contingency percentage to that subtotal.
The planning sum insured rounds the component total up to the next $10,000 so the result does not suggest false precision. The starting figures are editable examples only; they are not claimed New Zealand averages or insurer rates.
Sum insured is not market value
The land is not rebuilt after a total loss. Purchase price, council rating value and online property estimates answer a different question from the cost of demolishing and rebuilding insured structures.
Check what the rate already includes
Some professional or online estimates already include demolition, debris removal, fees, GST and escalation. Leave those calculator fields at zero if adding them would count the same cost twice.
Special features may sit outside the total
Retaining walls, pools and unusual structures can have a policy sub-limit, need to be specified separately or be excluded. The calculator cannot decide where an insurer places them.
Complex homes need professional input
A steep or restricted site, heritage construction, unusual materials, high-end finishes or extensive external works can make a simple area-based estimate unreliable.
How to compare home insurance prices
Ask each insurer to quote the same sum insured, excess and optional benefits. Then compare the basis of settlement, natural-hazard cover, temporary accommodation, gradual-damage limits, retaining-wall and recreational-feature limits, exclusions and financial strength—not only the annual premium.
If one quote is much cheaper, check whether its cover, excess or address-level hazard assessment differs. Only an insurer can produce a price for the actual property.
New Zealand home insurance sources
These sources explain what a sum insured represents, which rebuild costs can matter and why the figure should be checked regularly. Current policy wording and professional advice take priority for a particular home.
Home insurance calculator questions
Does this calculator estimate my home insurance premium?
No. It estimates a possible rebuild sum insured from figures you enter. An insurer still needs your address and property details to price the premium, excesses and cover.
Is the sum insured the same as my home’s market value?
No. Market value includes the land and reflects what a buyer may pay. A rebuild sum insured is based on replacing the insured buildings and included features after a covered total loss.
Where should I get the rebuild rate per square metre?
Use an insurer-approved rebuild calculator or an estimate from a quantity surveyor, registered valuer, licensed builder or architect. Confirm whether that rate already includes GST, demolition and professional fees before adding them again.
What floor area should I enter?
Use the total building floor area across all levels, not the land area. Check whether an attached garage, decks, verandahs or other structures are already included in the figure you use.
Should I include retaining walls, pools and driveways?
Include their replacement cost only where it belongs under your policy. Some features have separate limits, need to be specified, or are excluded, so check the current policy wording or ask the insurer.
Does a rebuild estimate include GST?
It needs to reflect all costs that the sum insured is expected to cover, including GST where applicable. Check every estimate before combining figures so GST is neither omitted nor counted twice.
When should I use a professional insurance valuation?
Consider one for an unusual, high-value, heritage, multi-level or difficult-access home, or where retaining walls and special features are substantial. A professional can assess details a simple component calculator cannot.
How often should I review my house sum insured?
Review it at each renewal and after renovations or new external features. Building costs and policy terms change, and an insurer’s automatic adjustment may not reflect changes specific to your property.