When it comes to creating comfortable, efficient and long-lasting buildings, few elements are as essential as insulation. Whether you’re tackling a large-scale commercial project or a residential build, choosing the right insulation material can have a lasting impact on performance, cost, and even occupant wellbeing.
In this guide, we’ll unpack the key differences between fibreglass and wool insulation — two of the most common materials in Australian construction — and explore how they stack up across thermal, acoustic, fire and sustainability considerations. For more information on truly sustainable insulation products you can read our blog about the rise of eco-insulation.
From underfloor insulation to acoustic panels and Anticon insulation, this is your complete building insulation guide to help you select the best fit for your project in WA.
Understanding the Role of Insulation
Insulation acts as a barrier to heat flow, keeping interiors warmer in winter and cooler in summer. But today’s insulation products do far more than regulate temperature. They also help reduce noise transmission, improve energy efficiency, and create healthier indoor environments.
In Australia, insulation is measured by its R-value — the higher the R-value, the greater the material’s resistance to heat flow. However, R-value alone doesn’t tell the full story. Material composition, installation method, moisture resistance and acoustic performance all play a role in determining which product performs best for a given space.
Want to understand how insulation fits into WA’s compliance requirements? This blog covers the Westgyp insulation products designed to meet NCC standards across every type of build.
Fibreglass vs Wool Insulation: A Closer Look
Let’s break down the key attributes of these two materials and where each shines.
1. Material Composition and Source
- Fibreglass Insulation (e.g. Ecowool Insulation)
Made from fine strands of glass fibres bonded together, fibreglass is a synthetic insulation material that’s widely available and cost-effective. Products like Ecowool insulation are produced using sand and recycled glass, melted at high temperatures and spun into thin fibres. Ecowool is engineered for comfort, low dust and improved handling, making it a high-performing modern fibreglass option. - Wool Insulation
Wool insulation, on the other hand, is a natural product, often made from sheep’s wool blended with recycled fibres or synthetic binders for stability. It’s renewable, biodegradable, and naturally regulates humidity — making it ideal for eco-conscious builds and sustainable projects.
2. Thermal Performance
Both materials perform strongly in terms of thermal resistance, but the differences lie in how they handle real-world conditions.
- Fibreglass (e.g. Ecowool):
Offers excellent R-values for its cost and is available in batts, rolls and loose-fill forms. Ecowool insulation is designed to maintain consistent thermal performance over time, with low moisture absorption and high compressive recovery. However, like other fibreglass types, performance can drop if it becomes damp or compressed.
- Wool:
Wool fibres naturally trap air, providing stable thermal performance even when exposed to varying humidity. Because it can absorb and release moisture without losing insulating capacity, wool maintains a consistent R-value across seasons — a big advantage in high-moisture areas or coastal builds.
Verdict: For pure cost-to-performance ratio, fibreglass (such as Ecowool) wins. But for long-term stability and comfort in variable climates, wool has the edge.
3. Acoustic Performance
Sound control is an often-overlooked part of insulation selection, especially in multi-residential or commercial builds.
- Fibreglass (e.g. Ecowool Acoustic Range):
Its dense, fibrous structure effectively dampens sound, making it a popular choice for acoustic insulation panels and partition walls. Ecowool’s acoustic batts offer excellent noise reduction properties and can be used in walls, ceilings and floors to enhance sound privacy.
- Wool:
Wool performs similarly well acoustically — its irregular fibre structure diffuses sound waves rather than reflecting them. Some builders even prefer wool for acoustic applications due to its natural damping qualities.
Verdict: It’s a draw. Both materials perform well, but fibreglass options like Ecowool provide a more cost-efficient solution with strong acoustic ratings.
4. Fire Resistance
This is one area where fibreglass typically takes the lead.
- Fibreglass (Ecowool):
Non-combustible and naturally resistant to fire, fibreglass insulation doesn’t burn — it simply melts at very high temperatures. Ecowool insulation meets stringent Australian fire safety standards, making it particularly well-suited for compliance in commercial and multi-storey residential builds. - Wool:
Wool is also fire-resistant to a point — it self-extinguishes and won’t melt or drip like some synthetics. However, depending on its blend and binders, its overall fire rating may be slightly lower than fibreglass.
Verdict: For maximum fire safety and compliance, fibreglass (like Ecowool) is the preferred choice.
5. Handling and Installation
Anyone who’s worked with fibreglass knows it can be a little itchy.
- Fibreglass (Ecowool):
Modern formulations like Ecowool have improved handling significantly. Its softer texture and reduced dust levels make installation safer and more comfortable than traditional fibreglass products. While gloves and masks are still recommended, installers often report a noticeably easier experience. - Wool:
A clear winner here. Wool insulation is comfortable and safe to handle without protective clothing. It doesn’t irritate skin or lungs and can even contribute to better indoor air quality by absorbing airborne contaminants.
Verdict: For comfort, wool still leads — but Ecowool’s advancements make fibreglass handling much more installer-friendly.
6. Sustainability and Environmental Impact
Sustainability is playing a larger role in material selection than ever before, especially across WA’s growing eco-conscious building sector.
- Fibreglass (Ecowool):
Ecowool insulation is manufactured using up to 80% recycled glass and is certified under international standards for low environmental impact. The product’s low embodied energy and recyclable composition make it one of the more sustainable synthetic insulation options on the market. - Wool:
As a natural, renewable resource, wool has the lowest embodied energy of the two. It’s biodegradable, recyclable, and even acts as a passive air filter by binding volatile organic compounds (VOCs).
Verdict: For projects prioritising sustainability or aiming for green certification, wool is the superior option — but fibreglass products like Ecowool are bridging the gap with strong eco credentials.
Cost Comparison
Budget often drives material choice, especially on large builds.
- Fibreglass insulation, including Ecowool, remains one of the most affordable insulation materials in Australia, offering a high R-value at a lower cost per square metre.
- Wool insulation, while more expensive upfront, can deliver long-term value through durability, moisture regulation and health benefits.
For most residential builders, fibreglass (especially Ecowool) remains the go-to for cost efficiency. But for premium, sustainable or wellness-focused projects, the extra investment in wool can pay off.
When to Choose Each Material
Here’s a quick guide to matching insulation type to project requirements:
| Project Condition | Recommended Insulation | Reason |
| Budget-conscious builds | Fibreglass (Ecowool) | Affordable, high R-value and widely available |
| High-moisture environments (bathrooms, coastal homes) | Wool | Maintains R-value when damp |
| Acoustic performance (stud walls, ceilings) | Ecowool Acoustic | Specifically designed for its acoustic properties |
| Fire-rated applications | Fibreglass (Ecowool) | Non-combustible and compliant |
| Allergy-sensitive or wellness builds | Fibreglass (Ecowool) | Chemical-free and non-irritating |
| Eco-conscious or sustainable projects | Fibreglass (Ecowool) | Renewable, biodegradable and low embodied energy |
Don’t Forget the System Around It
Insulation performs best when paired with the right complementary products.
For example, combining Anticon insulation with plasterboard or acoustic panels can enhance both energy efficiency and noise control. Similarly, effective underfloor insulation ensures complete thermal performance — not just in the walls and ceiling but across the whole building envelope.
Choosing the best insulation in WA isn’t just about materials — it’s about the right system, correctly installed.
Which insulation is best?
There’s no one-size-fits-all solution when it comes to insulation. The best choice depends on your project’s priorities — whether that’s cost, sustainability, comfort, or compliance.
- For cost efficiency, fire performance and versatility: fibreglass insulation such as Ecowool remains a reliable workhorse.
- For sustainability, comfort and health: wool insulation offers a natural, future-ready alternative.
By understanding the strengths of each, builders and specifiers can deliver spaces that perform beautifully — for clients, the environment, and the long term. If you are needing assistance with calculating how much insulation you actually need for your project, read this blog, or contact our team and we will be able to assist.