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Insulation Calculator
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Insulation R-Value Lookup
Zone 1–3: Ceiling R4.1, Wall R2.8, Floor R1.0
Zone 4–5: Ceiling R5.1, Wall R2.8, Floor R2.0
Zone 6: Ceiling R5.1, Wall R2.8, Floor R2.25
Zone 7–8: Ceiling R6.3, Wall R3.8, Floor R3.0
Area + Waste: Area × (1 + Waste ÷ 100)
Zone 4–5: Ceiling R5.1, Wall R2.8, Floor R2.0
Zone 6: Ceiling R5.1, Wall R2.8, Floor R2.25
Zone 7–8: Ceiling R6.3, Wall R3.8, Floor R3.0
Area + Waste: Area × (1 + Waste ÷ 100)
Note: Minimum R-values based on NCC 2022 requirements for Australian climate zones.
Insulation Calculator — R-Values & Quantities by Climate Zone
The NCC 2025 increased minimum insulation R-values across all Australian climate zones (ABCB). Getting your insulation specification and quantities right is now more important than ever for compliance and energy efficiency.
Minimum R-Values by Climate Zone (NCC 2025)
| Climate Zone | Example Cities | Ceiling | Walls | Floor |
|---|---|---|---|---|
| Zone 1 (Hot humid) | Darwin, Cairns | R4.6 | R2.8 | R1.0 |
| Zone 2 (Warm humid) | Brisbane, Gold Coast | R5.1 | R2.8 | R1.0 |
| Zone 3 (Hot dry) | Alice Springs | R5.1 | R2.8 | R2.0 |
| Zone 4 (Hot dry summer) | Mildura | R5.1 | R2.8 | R2.0 |
| Zone 5 (Warm temperate) | Sydney, Perth, Adelaide | R5.1 | R2.8 | R2.0 |
| Zone 6 (Mild temperate) | Melbourne | R6.0 | R2.8 | R2.5 |
| Zone 7 (Cool temperate) | Hobart, Canberra | R6.0 | R2.8 | R3.0 |
| Zone 8 (Alpine) | Mt Buller, Thredbo | R7.0 | R3.8 | R3.5 |
Insulation Coverage per Pack
| Product | R-Value | Width | Coverage/Pack |
|---|---|---|---|
| Ceiling Batts | R5.0 | 430/580mm | 5.3–8.3 m² |
| Ceiling Batts | R6.0 | 430/580mm | 4.0–6.4 m² |
| Wall Batts | R2.5 | 430/580mm | 8.3–11.7 m² |
| Wall Batts | R2.8 | 430/580mm | 6.9–9.3 m² |
| Underfloor Batts | R2.5 | 430/580mm | 7.0–9.5 m² |
Tips for Insulation Ordering
- Measure ceiling area accurately — deduct for downlights with required clearance zones.
- Use 430mm batts for 450mm stud spacing, 580mm for 600mm spacing.
- Add 5% extra for cutting and fitting around pipes, wiring, and framing.
- Check your NCC climate zone before specifying — minimum R-values increased in 2025.
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