House Sum-Insured Calculator
Estimate the rebuild cost for your home using NZ regional $/m² benchmarks. Avoid underinsurance after the EQC cap increase to $300k.
About this calculator
This calculator implements BRANZ residential building cost data + regional rebuild rates from Cordell / BRANZ. Last consulted 18 May 2026. Verify the figures yourself by following the link.
NZ rebuild cost benchmarks ($/m²)
BRANZ + insurance industry data 2026- •Standard Auckland single-storey: ~$3,500/m²
- •Standard Auckland two-storey: ~$3,900/m²
- •Canterbury standard: ~$3,100-3,500/m²
- •Premium quality multiplier: +20%
- •Demolition allowance: 10% of base rebuild
- •Professional fees (consents, etc.): 12% of base rebuild
- •EQC cap (natural disaster): $300,000 + GST
Source: BRANZ — Building cost data
Disclaimer
This calculator provides estimates for general information purposes only. Results should not be relied upon as professional financial, tax, or legal advice. Tax rates and thresholds are based on publicly available IRD data and may change. Always consult a qualified tax agent or financial adviser for advice specific to your circumstances.
How NZ house rebuild cost is estimated
Cordell-style $/m² benchmarks × floor area × adjustments + demolition + professional fees.
- 1
Base cost per m²
Base_rate = regional_$/m² (Auckland 1-storey ~$3,500/m²)
Higher for two-storey (~+10%) and premium finishes (~+20-45%).
- 2
Base rebuild cost
Base_cost = floor_m² × rate × quality_multiplier
Quality: basic 0.85, standard 1.0, high 1.20, premium 1.45.
- 3
Add demolition
Demolition = base_cost × 10%
Site clearance after destruction.
- 4
Add professional fees
Pro_fees = base_cost × 12%
Consent, architect, engineer, QS.
- 5
Add features
Total = base + demolition + pro_fees + extras (pool, sleepout)
Extras: pool ~$60k, sleepout ~$30k, large shed ~$25k.
Worked example
Inputs: Auckland 180m² standard single-storey, pool $30k
Result: Base 180 × $3,500 = $630k. + demolition $63k + pro fees $76k + pool $30k = ~$799k.
Frequently Asked Questions
Why does my house sum-insured matter so much?
Does my sum-insured need to cover EQC?
How this calculator works
This house sum-insured calculator uses the latest data from official New Zealand government sources to provide accurate results. All calculations are performed in your browser — your data never leaves your device.
All calculations are performed in your browser — your data never leaves your device. Results are for general guidance only and should not be considered professional financial advice.
Built and maintained by Konstantin Iakovlev. Data sourced from the IRD and official New Zealand government sources.
Last reviewed: