Insulation Calculator — NZ R-Value & Area

Calculate how much insulation you need for your NZ home — ceiling, underfloor, and wall insulation. R-values, batts, and cost estimates.

NZ Insulation Requirements (H1 2023)

The NZ Building Code clause H1 (Energy Efficiency) was significantly updated in 2023, raising minimum R-values across all climate zones. All new builds and major renovations must comply.

NZ Climate Zones

Zone Cities Min ceiling R-value
1 Northland, Auckland R 6.6
2 Waikato, BOP, Gisborne R 6.6
3 Hawke's Bay, Wellington, Taranaki R 4.0
4 Nelson, Marlborough, West Coast R 4.0
5 Canterbury, Otago R 3.3
6 Southland, Fiordland R 3.3

Insulation Grants

Check if you qualify for Warmer Kiwi Homes grants — eligible homeowners can receive up to 66% subsidy on insulation installation. Visit EECA Energywise for details.

Typical Installed Costs

  • Ceiling insulation: $18–$30/m² installed
  • Underfloor insulation: $20–$28/m² installed
  • Wall insulation (new build): $25–$40/m² installed