Ceiling Insulation Types Guide 2025
Complete comparison of insulation materials available in New Zealand, with performance data, costs, and recommendations
Polyester Batts
Made from recycled plastic bottles, polyester batts are the premium choice for New Zealand homes. They offer excellent moisture resistance and consistent performance in our humid climate.
✓ Pros
- Moisture resistant
- Non-allergenic
- Fire resistant
- Rodent resistant
- Easy to handle
- Long lifespan
✗ Cons
- Higher upfront cost
- Limited thickness options
- Synthetic material
Glasswool Batts
Made from recycled glass, glasswool (also called glasswool) is the most affordable insulation option. Popular for budget builds but requires careful handling during installation.
✓ Pros
- Lowest cost option
- Fire resistant
- Good thermal performance
- Wide availability
- Recyclable
✗ Cons
- Itchy to handle
- Can sag over time
- Absorbs moisture
- Shorter lifespan
- Requires protective gear
Natural Wool
Made from sheep's wool, this is the premium natural option. Excellent thermal properties and environmental credentials, but comes at a higher cost.
✓ Pros
- 100% natural
- Breathable material
- Fire resistant
- Manages humidity
- Pleasant to handle
- Sustainable
✗ Cons
- Highest cost
- Can attract pests
- Limited availability
- Requires pest treatment
Reflective Foil
Combines bulk insulation with reflective foil backing to reduce radiant heat transfer. Excellent for hot climates but limited winter performance.
✓ Pros
- Excellent summer cooling
- Moisture barrier
- Easy installation
- Dual function
- Moderate cost
✗ Cons
- Limited winter benefit
- Foil can tear
- Requires air gap
- Complex installation