# Home insurance calculator > Free NZ home insurance calculator. Estimate your rebuild cost from floor area, construction type, build quality and location, then set your sum insured. Canonical: https://kapiinsurance.co.nz/home-insurance/calculator/ Estimate your home's rebuild cost and get your sum insured right. Treasury analysis has estimated up to 85% of NZ homes are underinsured. Your sum insured is what it costs to rebuild your home from scratch, not the market value. This calculator estimates rebuild cost based on NZ construction data, including demolition, professional fees, and an inflation buffer. ## Your property details sqm All levels combined. Average NZ standalone: 150 sqm. Standard covers a typical NZ new build with decent fittings. Each additional bathroom adds approx. $25,000. Swimming or spa pool Adds approx. $45,000 for a standard in-ground pool. Deck or patio Retaining walls Cover limits for retaining walls vary by policy. Adds approx. $30,000 to rebuild. ## What is sum insured and why does it matter? Sum insured is the maximum your insurer will pay to rebuild your home after a total loss. After the Canterbury earthquakes, NZ insurers moved away from full replacement policies. Now every homeowner sets their own figure. Get it wrong and you carry the gap yourself. The number is a construction cost, not a property price. It covers knocking down the damaged structure, clearing the site and rebuilding to current NZ Building Code standards, plus the professional fees: architects, engineers, council consent. All of it comes out of your sum insured. ### What affects rebuild cost in New Zealand? Floor area and build quality are the biggest drivers. A standard 150 sqm home in Auckland costs roughly $480,000 to $540,000 to rebuild at 2025 rates. Add demolition, professional fees and an inflation buffer, and you can be looking at $600,000 or more. Two-storey homes cost roughly 15% more per sqm than single-storey. Masonry or brick adds another 10-25% over standard timber frame. Steep sections or sites with difficult access push costs higher again. In Auckland, Wellington or Queenstown, labour runs above the national average. Your [home insurance](https://kapiinsurance.co.nz/home-insurance/) premium is built on this rebuild figure. ### Why do the calculator, your insurer and your purchase price disagree? Each number measures something different, so disagreement is normal. Your purchase price includes the land, and land is not insured, which is why a sensible sum insured usually sits well below what you paid. Your insurer's renewal figure is often an earlier estimate rolled forward with an inflation adjustment. The online calculator most insurers point you to, Cordell Sum Sure, estimates rebuild cost from council records and construction data. Sum Sure's estimate includes construction costs, professional fees, demolition, debris removal and GST, with regional price adjustments. It assumes standard finishes and an average-sized garage or shed, and it does not allow for future cost increases. If the prefilled details are wrong, or your home is far from standard, the estimate will be too. None of the three numbers is right by default. What rebuilding your actual home would cost is the figure you want, and the calculator above plus a broker's review gets you close. ### What happens above the Natural Hazards Commission cap? Your private insurer pays the damage above $345,000, up to your sum insured. The Natural Hazards Commission Toka Tū Ake (formerly EQC) provides NHCover, which covers the first $345,000 including GST of natural hazard damage to your home, per event. You only have NHCover while you hold a current private home policy that includes fire cover. On any home with a rebuild cost above the cap, the insurer carries the gap to the limit of your sum insured. If that figure is too low, you pay the difference. Several New Zealand insurers offer a top-up benefit that pays a set percentage above your sum insured for natural hazard claims. It helps when your figure turns out to be low. The condition is usually a rebuild estimate from an accepted source: a registered valuer, a building practitioner or the insurer's own calculator, and it generally has to be recent. Names, percentages and qualifying conditions differ between insurers. Check the wording on the quote in front of you. ### What your sum insured should include - Full rebuild cost of the dwelling to current Building Code standards - Demolition and site clearance ($25,000 to $50,000 depending on construction type) - Professional fees: architect, structural engineer, geotechnical engineer, surveyor, council consent (typically 12% of construction cost) - Outbuildings, garages, and carports - Additional features: decks, retaining walls, swimming pools, driveways, fences - An inflation buffer (roughly 6%) to account for construction cost increases during the 12 to 18 months it takes to rebuild - GST. Sum insured figures in New Zealand are normally GST inclusive, and Sum Sure includes it. If a quantity surveyor gave you a GST-exclusive figure, gross it up before you use it ### When is a quantity surveyor worth paying for? A quantity surveyor or registered valuer earns their fee when the online tools cannot model your home. Architecturally designed or high-value houses, steep or hard-access sites, heritage features, superior finishes, unusually large floor plans, and addresses the calculator does not recognise all fall into that bucket. The fee for a professional rebuild estimate is small next to a six-figure shortfall after a total loss. A professional estimate has a second use. The natural hazard top-up benefits some insurers offer only apply if you hold a recent rebuild estimate from an accepted source, and a quantity surveyor's report typically qualifies. Check your policy wording for what your insurer accepts and how recent the estimate needs to be. ### How do you insure a shared-wall townhouse? Title type decides who insures a shared-wall townhouse. In a unit title development, the body corporate must insure all buildings on the land to their full insurable value under the Unit Titles Act 2010. You pay your share through body corporate levies and insure your own contents separately. If every unit is a stand-alone building, the Act lets the body corporate pass insurance back to individual owners by special resolution, so check your body corporate rules. A fee simple (freehold) townhouse works like any other house. You insure your own home under your own policy even though a wall is shared, and your neighbour insures theirs. Tell the insurer the home is attached so the rebuild assumptions are right. If you are not sure which title you have, it is on your record of title, and it is worth confirming before you pay for cover the body corporate may already provide. ### NZ construction costs per square metre (2025) | Build quality | Cost per sqm (NZD) | Description | | --- | --- | --- | | Budget | $2,400 - $2,800 | Simple design, standard materials, basic fittings | | Standard | $2,900 - $3,600 | Typical NZ new build with decent fittings | | Premium | $3,800 - $5,200 | Quality fittings, engineered timber or steel | | Luxury | $5,500 - $8,000+ | Bespoke architectural design, high-end materials | Sources: Rawlinsons NZ Construction Handbook, BRANZ building cost studies, CoreLogic Cordell benchmarks. Figures include GST. Regional variations apply. Sum insured is a construction number: demolition, consents, professional fees and the rebuild itself. ### Not sure if your sum insured is right? Use this calculator as a starting point, then talk to a broker. Kapi Insurance reviews your sum insured against your property details and flags anything that looks off. No obligation. ## Common questions about sum insured ### What is sum insured? Sum insured is the maximum amount your insurer will pay to rebuild your home. It should cover demolition, rebuilding to current Building Code standards, professional fees, and an inflation buffer. It is not the market value or sale price. ### How much does it cost to build a house in NZ? NZ residential construction costs range from about $2,400/sqm for a basic build to $5,500/sqm or more for a luxury home. A standard 150 sqm home costs roughly $435,000 to $540,000 in construction alone, before demolition, professional fees, and inflation. ### What does the Natural Hazards Commission (formerly EQC) cover? The Natural Hazards Commission Toka Tū Ake provides NHCover, which pays the first $345,000 (including GST) of natural hazard damage to your home, per event. It covers earthquake, landslide, volcanic activity, hydrothermal activity and tsunami, and applies only while you hold a current private home policy that includes fire cover. ### How often should I update my sum insured? Review your sum insured at least once a year. Construction costs in NZ have risen significantly in recent years. If you have done renovations, added rooms, or upgraded your kitchen or bathrooms, update your sum insured to reflect the increased rebuild cost. ### Is sum insured the same as market value? No. Market value includes land, location, and what buyers will pay. Sum insured is purely the cost to demolish and rebuild the physical structure. In some areas, rebuild cost exceeds market value. In others, land value makes market value much higher. They are separate numbers. ### What happens if the rebuild costs more than your sum insured? You pay the difference, unless your policy includes a top-up benefit. Several New Zealand insurers offer one that pays a set percentage above your sum insured for natural hazard claims, usually only if you hold a recent rebuild estimate from an accepted source. Names, percentages and conditions differ, so check your policy wording. ### Why do the calculator, my insurer and my purchase price all disagree? Each number measures something different. Your purchase price includes land, which is not insured. Your insurer's default figure is often an older estimate carried forward with indexing. The online calculator estimates rebuild cost from council data and standard finishes. The right number is what rebuilding your actual home would cost. ### Should GST be included in my sum insured? Yes. Sum insured figures in New Zealand are normally GST inclusive. The Cordell Sum Sure calculator includes GST in its estimate, and insurer guidance says your sum insured should include it. If a quantity surveyor gave you a rebuild figure, check whether it includes GST before using it. ### How do you insure a shared-wall townhouse? It depends on your title. In a unit title development, the body corporate must insure all buildings to their full insurable value under the Unit Titles Act 2010, and you insure your contents. With a fee simple (freehold) townhouse, you insure your own home under your own policy, shared wall included. ### When is a quantity surveyor worth paying for? A quantity surveyor or registered valuer earns their fee when an online calculator cannot model your home: architecturally designed or high-value houses, steep or hard-access sites, special features, or an address the calculator does not recognise. Their rebuild estimate also counts as an accepted source for some insurers' natural hazard top-up benefits. Coverage examples on this page reference publicly available New Zealand policy wordings. Sub-limits, benefits, and conditions vary between insurers, so check your own policy.