# S-P06-H-02: How can we check our rebuild sum insured after renovating for a growing family? Collected 11 October 2026 [Home and contents insurance study](https://nzbrands.ai/research/insurance/home-contents-insurance) ## ChatGPT Answer ID: c7705aa9-b0a5-48ea-8b94-fbb1e04eedd2 If you’ve renovated your home to make more room for a growing family, the best time to check your rebuild sum insured is now — rather than waiting until your next renewal. In New Zealand, your sum insured is the maximum amount your insurer will generally pay towards rebuilding your home after a major insured loss, subject to your policy terms. Renovations can increase the cost of rebuilding, particularly if you’ve added bedrooms, bathrooms, living space or higher-quality fittings. [House & Contents Insurance: Sum Insured Explained](https://www.icnz.org.nz/individuals/house-contents/)[Home renovation](https://www.consumer.org.nz/home-and-living/building-and-renovation/renovation-guide-5-finances-insurance) Here’s a practical way to check whether your cover is still enough. ## 1. Recalculate your home's rebuild cost Start with the home you have now Check your current policy schedule and note the existing sum insured. Then update your home's details to reflect the completed renovations, including any extra floor area, bedrooms, bathrooms, storeys and changes to construction quality. Use a rebuild cost calculator Try the free Cotality Sum Sure calculator, available through many New Zealand insurers. Enter your home's current details rather than relying on an old estimate. Use the calculator provided or recommended by your insurer where possible. Include the costs beyond the house itself Check whether the estimate allows for demolition, debris removal, professional fees, consents, GST where applicable, and relevant features such as decks, driveways, fences, retaining walls and garages. You can start with the [Insurance Council of New Zealand's sum insured guidance](https://www.icnz.org.nz/individuals/house-contents/) and your insurer's calculator. [Home Sum Insured](https://www.nzi.co.nz/personal-cover/home-insurance/home-sum-insured)[House & Contents Insurance: Sum Insured Explained](https://www.icnz.org.nz/individuals/house-contents/) ## 2. Check whether your renovations are fully reflected Use this checklist to make sure nothing has been missed. ### Rebuild review checklist 0 of 7 checked Added floor area, bedrooms or bathrooms Renovated kitchen, bathrooms and fixed fittings Higher-spec materials or bespoke architectural features Garage, sleepout, deck, patio or other additions Driveways, fences, retaining walls and other outdoor structures Demolition, debris removal, professional fees and consents Possible increases in building costs during the insurance period ## 3. Decide whether you need a professional estimate An online calculator is a useful starting point, but consider getting a rebuild assessment from a quantity surveyor or registered property valuer if you have: - Added a substantial extension or another storey. - Used expensive or non-standard materials and finishes. - A steep or difficult-to-access building site. - Significant retaining walls or other features that may need separate cover. Ask your builder for the renovation plans, final floor area and specifications to help with the assessment. Remember that what you spent on renovations is not necessarily what it would cost to reconstruct them following a total loss. [ICNZ Consumer Guide 2025 – Sum Insured: What it is and why it matters](https://www.icnz.org.nz/wp-content/uploads/2025/04/ICNZ-Consumer-Guide-2025-%E2%80%93-Sum-Insured-What-it-is-and-why-it-matters-1.pdf)[Home Insurance Sum Insured - estimate rebuild costs](https://www.asb.co.nz/home-and-contents-insurance/sum-insured.html) ## 4. Update your insurer — don't just rely on renewal Contact your insurer or broker and ask them to confirm: - Your current sum insured reflects the renovated house. - The policy covers the new floor area and features. - Whether special features need separate cover. - Whether GST is included in your sum insured. - Whether your policy is based on a fixed sum insured or offers a different form of replacement cover. Also check your contents insurance. A growing family may have accumulated more beds, furniture, appliances, clothing and children's belongings, which could leave your contents cover inadequate too. [How to get the best house and contents insurance](https://www.consumer.org.nz/money/insurance/house-and-contents-insurance/guide)[House & Contents Insurance: Sum Insured Explained](https://www.icnz.org.nz/individuals/house-contents/) ## Where to start Use the [Cotality Sum Sure rebuild estimate information](https://www.cotality.com/nz/products/cordell-sum-sure) and check whether your insurer offers access to its calculator. The estimate is a guide, not a guarantee of the actual cost to rebuild. [Online Property Rebuild Cost Calculator](https://www.cotality.com/nz/products/cordell-sum-sure)[Home Insurance Sum Insured - estimate rebuild costs](https://www.asb.co.nz/home-and-contents-insurance/sum-insured.html) My recommendation: recalculate using your renovated home's details, compare the result with your current sum insured, and ask your insurer to update the cover now if needed. Review it again at each renewal and after future renovations. ## Gemini Answer ID: 90660b4d-6b0d-4ea6-8995-10a20e4f4b23 Completing a renovation for a growing family (such as adding a bedroom, expanding the living space, or putting in an extra bathroom) means your old house insurance sum insured will likely be **under-insured**. In New Zealand, insurance policies operate strictly on a sum insured basis, meaning you are responsible for setting a figure that covers a complete rebuild from the ground up. Updating and checking your rebuild sum insured after a renovation involves several key steps: ### 1. Update Your Property’s Specs The fundamental drivers of a rebuild cost are floor area and quality of finishes. Gather your renovation details: * **New Floor Area:** Calculate the exact square meters added to your footprint (e.g., extensions). Even internal alterations that change layout or upgrade quality affect costs. * **Materials and Specification:** Did you upgrade from standard gib and carpet to high-end tiles, double glazing, or a custom kitchen? Insuring a property requires factoring in the *current* cost of those specific materials and modern building compliance standards. * **External Additions:** Don't forget secondary structures impacted or added during the re-vamp, such as expanded decks, retaining walls, or larger driveways. ### 2. Use a New Zealand Rebuild Calculator Most major New Zealand insurers (such as AMI, State, Vero, and AMP) endorse or provide free access to the **Cordell Sum Sure Calculator**. * Input your updated address, or manually adjust the parameters to reflect your newly expanded floor plan and upgraded specifications. * *Tip:* These tools automatically account for standard demolition, debris removal, council consent fees, and professional fees (architects/engineers) which spike during a complete rebuild. ### 3. Consider a Professional Assessment for Custom Work If your renovation involved complex architectural designs, high-end bespoke finishes, or if your home is on a difficult sloping section, an online calculator may not capture the total expense. For peace of mind: * Engage a **Registered Quantity Surveyor** or an independent **Property Valuer** to complete a detailed, tailored replacement cost estimate. * Their report will give you an ironclad figure to hand straight to your provider. ### 4. Factor in Compliance and Inflation * **Current Building Code:** Rebuilding a home requires compliance with modern New Zealand Building Codes (e.g., insulation, bracing, double glazing), which can be significantly more expensive than what your house originally featured. * **Build Inflation:** Construction costs fluctuate rapidly. Ensure your final sum insured figure builds in a buffer for potential material and labor cost inflation over the next 12 months. ### 5. Contact Your Insurer Once you have your new figure, notify your insurance company immediately. Failing to update your policy post-renovation risks being hit by the "average clause" or underinsurance, meaning a payout might only cover a fraction of a rebuild. Ask your provider if they offer a "SumExtra" or similar policy benefit, which provides a safety net buffer percentage if you've accurately calculated your home using an approved tool like Cordell. ## AI Overviews Answer ID: 437d3025-a160-44c4-9be1-6d0398300895 Checking your rebuild sum insured after a renovation is a vital step to ensure you aren't underinsured. In New Zealand, **the homeowner is completely responsible for setting and updating the home's sum insured**. Because your family home now has a larger footprint, updated materials, or extra bedrooms, your previous insurance cap will likely no longer cover a total loss. Here is how you can check and update your rebuild sum insured at a national level: 1\. Gather Your New Property Specifications Before calculating, make sure you have the exact details from your recent renovation handy: * **Total floor area:** The final total size of the house in square metres (including the new extension). * **Materials used:** Note down specific roof, wall, and framing materials used by your builder. * **External extras:** Don't forget new decks, fences, retaining walls, or detached sleep-outs built to accommodate your growing family. 2\. Use a Free Online Rebuild Calculator Most major New Zealand insurers point customers to the **Cordell Sum Sure Calculator** (sometimes branded as _Cotality_). * **How it works:** You enter your address, and it pulls data from council records. * **What you must do:** Because council records won't immediately show your recent renovations, you must manually adjust the floor area, room counts, and material quality to match your home's new state. * **What it includes:** The calculator automatically builds in standard New Zealand costs for **demolition, debris removal, council consent fees, professional architect fees, and GST**. _Note: Major providers likeAA Insurance, AMI, State, Vero, and Tower host versions of this calculator directly on their websites._ 3\. Seek a Professional Assessment (For Bespoke or High-Value Renovations) If your renovation involved complex architectural designs, premium high-spec materials, or difficult site access (e.g., a steep hill section), online calculators can under-estimate the true cost. Consider hiring: * A **Quantity Surveyor (QS)** or a **Registered Valuer** to provide a formal insurance rebuild valuation. * Your **Licensed Building Practitioner (LBP)** or architect who managed the renovation to give you a rough breakdown of current replication costs. 4\. Review the "SumExtra" Policy Advantage When updating your policy, check if your insurer offers a **SumExtra** benefit (available with companies like Vero and AMP). If you calculate your rebuild cost using their approved online calculator and insure your house to at least that amount, the insurer may pay out up to 10% to 20% extra if your home is destroyed and inflation pushes the actual rebuild costs over your limit. 5\. Contact Your Insurer to Update the Policy Once you have your new figure, log into your online banking/insurance portal or call your provider directly to officially change your sum insured. Your monthly premium will likely adjust slightly, but your renovated family home will be fully protected. * * * If you'd like to narrow this down, please let me know: * Who is your current **insurance provider**? * Did the renovation significantly alter the **building materials** (e.g., switching from weatherboard to brick) or add specific **outdoor features** like a retaining wall? I can guide you to the exact tool or policy rules for your situation. ## Google AI Mode Answer ID: e9b952dc-d3e4-41f3-994a-83f0dc691d2b Reviewing your rebuild **sum insured** after a major renovation is essential to ensure your growing family isn’t left underinsured. Standard annual inflation adjustments on your policy do not account for major structural extensions, extra rooms, or high-end material upgrades. Here are the key steps to accurately check and update your home sum insured in New Zealand: * * **Use an online calculator:** Most major New Zealand insurers (such as State Insurance, ASB, and Tower) provide free access to the **Cordell Sum Sure** (or Cotality Sum Sure) calculator. Enter your updated floor plans, new square meterage, and upgraded specifications to generate a realistic baseline rebuild estimate. * **Include all hidden rebuild costs:** Your new sum insured must cover the absolute total cost of clearing and rebuilding from scratch. Ensure your figure factors in demolition, debris removal, council consent and compliance fees, architectural/engineering professional fees, and **GST**. [State Insurance NZ] * **Account for material and labor upgrades:** If your renovation swapped out standard materials for premium finishes (e.g., engineered timber floors, custom kitchens, double glazing, or extra bathrooms), manually adjust your calculator inputs to reflect these higher building standards. * **Consult a professional for complex or high-value builds:** If your renovation was architecturally unique, involved heritage elements, or pushed your total rebuild estimate past high-value thresholds (often around $1.5M+ depending on the insurer), consider hiring a **registered property valuer** or **quantity surveyor** for an accurate assessment. * **Contact your insurer directly:** Inform your insurance provider about the completed renovations, provide your new calculated sum insured figure, and save a copy of your updated calculation certificate or policy schedule for your records. * If you'd like, let me know: * Which **insurance provider** you are currently with * Roughly **what type of renovation** you completed (e.g., added a new bedroom, added a deck, or full interior refit) I can give you more specific details on their **calculator tools or policy benefits**.