When it comes to insulating your home in New Zealand, two of the most commonly used materials are Polyester Insulation and Glasswool Insulation.
Both are widely used, both meet New Zealand insulation standards, and both can make a significant difference to the comfort and energy efficiency of your home when installed correctly.
Rather than one being better than the other, the key is understanding how each option works and which is the right fit for your home and your goals.
Good Insulation Makes a Big Difference
Good insulation helps to:
Keep your home warmer in winter
Reduce heat entering during summer
Lower power bills
Improve overall comfort
Support Healthy Homes compliance for rentals
The material you choose plays a role, but just as importantly, it needs to be installed properly and suited to the space.
Polyester Insulation
Polyester insulation is made from durable, recycled fibres and is a popular choice in many New Zealand homes.
It’s often selected where comfort and ease of handling are important.
Key Features of Polyester Insulation:
Soft, non-irritating material
Holds its shape well over time
Good for both thermal and acoustic comfort
Suitable for ceilings, walls, and some underfloor applications
Because of its structure, polyester insulation can also help with reducing noise between rooms, which is an added benefit in many homes.
Glasswool Insulation
Glasswool insulation has been used in New Zealand for many years and is a trusted, widely installed product.
It’s made from spun glass fibres and is designed to deliver strong thermal performance.
Key Features of Glasswool Insulation:
Excellent thermal performance
Widely used and proven in NZ homes
Suitable for ceilings, walls, and under-floors
Available in a wide range of R-values
Glasswool remains one of the most common insulation choices due to its reliability and effectiveness.
Performance in Real Homes
Both Polyester and Glasswool insulation perform very well when:
The correct R-value is selected
The insulation fully covers the area
Installation is done to standard
In most cases, the difference in real-world performance comes down more to installation quality and coverage than the material itself.
Choosing the Right Option for Your Home
The best insulation choice depends on factors such as:
The area being insulated (ceiling, walls, or underfloor)
Your budget and priorities
Whether acoustic performance is important
The current condition of your home
In many cases, different products can even be used in different parts of the home to achieve the best overall result.
Grants and Approved Insulation
If your home is eligible for insulation funding, such as through Warmer Kiwi Homes, both Polyester and Glasswool insulation products may be suitable.
What matters most is that the insulation:
Meets required R-values
It is installed to the correct standard
Uses approved materials
We can help guide you through suitable options if funding is available for your property.
If you’re unsure which option is best, a professional assessment can help ensure you get the most effective result for your home.
Either fill in the form on our Contact page or
Phone us on 0800 327 946
to find out which insulation is the best for your home or rental property.
