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?
The house sum-insured calculator estimates the full rebuild cost of your home using NZ regional dollars-per-square-metre benchmarks, plus demolition, professional fees, and site features — the number your house insurance policy needs to be set to.
How this calculator works
Since the move to sum-insured policies, your insurer pays at most the figure you nominate — not "whatever it costs" — so underinsurance is the single biggest risk in NZ house cover. The calculator multiplies your floor area by a regional rebuild rate (a standard single-storey Auckland home runs about $3,500/m²; two-storey construction adds roughly 10%, and premium finishes 20-45%), then adds the costs almost everyone forgets: demolition and site clearance at about 10% of the base rebuild, and professional fees — consent, architect, engineer, quantity surveyor — at about 12%. Site features such as a pool (~$60k), sleepout (~$30k), or large shed (~$25k) are added on top. Remember EQC's natural-disaster cap is $300,000 + GST; your private insurer covers the rebuild above that, which is why the sum insured must be realistic. Reset it after renovations and at every renewal.
NZ rebuild cost benchmarks ($/m², 2026)
| Auckland standard single-storey | ~$3,500/m² |
| Auckland standard two-storey | ~$3,900/m² |
| Canterbury standard | ~$3,100 - $3,500/m² |
| Premium finish multiplier | +20-45% |
| Demolition allowance | 10% of base rebuild |
| Professional fees (consent, design) | 12% of base rebuild |
| EQC natural-disaster cap | $300,000 + GST |
Based on BRANZ and insurance-industry data; a registered valuer can provide a certified rebuild estimate.
Worked Examples
Auckland, 180 m² standard single-storey home with a pool
Suggested sum insured ≈ $799,000.
- Base rebuild: 180 m² × $3,500 = $630,000
- Demolition (10%): $63,000
- Professional fees (12%): $75,600
- Pool: $30,000
- Total: ≈ $799,000
Canterbury, 140 m² standard single-storey, no extras
Suggested sum insured ≈ $564,000.
- Base rebuild: 140 m² × $3,300 = $462,000
- Demolition (10%): $46,200
- Professional fees (12%): $55,400
- Total: ≈ $564,000
Built and maintained by Konstantin Iakovlev. Data sourced from the IRD and official New Zealand government sources.
Last reviewed: