Insulation is a crucial ingredient in achieving thermal comfort all year round. It is not only to protect us from winter cold but also from the summer heat.

In a new development like ecokit an accurate amount of the appropriate insulation in the perfect place is vital. But what is the insulation made from? Where does it come from? Are some choices healthier than others?

What we were considering
Sheep wool, Rockwool, Glass wool or recycled polyester batts – our choices have been limited by considering only healthy (no added formaldehyde or VOC) and sustainable (no petrochemical products) materials.

The process
We have chosen to use Glass wool products as they are from recycled glass rather than recycled plastic (petrochemical) such as polyester batts and the manufacture is cleaner and produces less carbon than the manufacture of mineral wool. Unfortunately sheep wool is too hard to source in Australia. It also needs to be chemically treated against pests and mould.

Glass is resourced and processed in Australia, so manufacturing miles are less than Polyester which is Post Consumer Waste collected world wide, sorted and primarily processed in Asia and China and imported for manufacturing in Australia.

There are different products of glass wool currently available on the australian market: Pink Batts, Bradford Gold & Earthwool by Knauf. According to the Pink Batt (glass wool) MSDS (material safety data list) the product has 2 – 16% heat cured phenol- formaldehyde resin. Similar for Bradford Gold, they claim the product contains <15% of formaldehyde. This is not good enough for us – we were looking for a formaldehyde free solution. This left us with Earthwool by Knauf.

Earthwool Wall batts are made using recycled glass and with ECOSE® Technology, a revolutionary binder based on rapidly renewable materials instead of petrochemical-based resins. ECOSE Technology reduces binder embodied energy and contains no added phenol, formaldehyde, acrylics or artificial colours. Earthwool is made using up to 80% recycled content glass and is 100% recyclable.

Our Final Choices
Earthwool batts, foil sarking, permeable house wrap. Building to be generally air tight.

To achieve the super insulation performance the building will require double layer of R2.5 bulk insulation. The two layers of R2.5 glass wool introduce an air layer in between the insulation, further improving the insulation properties. We have also added anti glare foil to the external cladding.

Ecokit house has been designed with a sustainability as one of the main focuses. The superior environmental characteristics of Earthwool with ECOSE Technology contributes to improving the overall sustainability of ecokit. And by eliminating phenol and formaldehyde from manufacturing process, the installation is safer and pollutant manufacturing emissions are significantly reduced.

Have you used Earthwool before and would you like to share your feedback with us? Or do you know about another suitable insulation we haven’t considered? Let’s talk…


About Camilla

My enthusiasm for changing lifestyles, determination to change the world, devotion to a positive change of any kind, love of innovative ideas and desire to always push the boundaries organically came together eventually - and so ecokit was born. Now I am proud to be doing what I enjoy and love - helping people to fulfill their dreams of living in a healthy, happy home.


  • Leonore says:

    Hi there, Did you consider Hemp Fibres as insulation?

    • Camilla says:

      Hi Leonore,

      actually, no we didn’t. Do you know where I can source Hemp Fibres in Australia? Could you please point me to a more information?

      Thanks, Camilla

  • Jenny Stirling says:

    I have used earthwool before and it was excellent. I was renovating an old miners cottage built completely of silky oak timber (in Queensland). We took down the ply ceiling and pushed up the earthwool into a small cavity before reattaching a gyprock ceiling onto the sloping steel roof. You could feel the difference straight away even though that room had low ceilings. The earthwool made it easy and was very light.

    • Camilla says:

      Hi Jenny,
      thank you for your feedback. We were looking for a product that was light and non-toxic while having a good insulating properties and glasswool seemed like one the best options. Glad you also had a good experience with it. Thanks for sharing.

  • Luke Poulton says:


    Is the above still what you guys believe? Or have more eco friendly options come to the fore. I am currently looking at insulation & and want to use the most environmentally friendly option. Also looked at natural wool but not attainable.

    • Camilla says:

      Hi Luke,

      there are few angles to look at any materials – we look at absence of toxic residues first, for example. Then it’s the procuring and production, how easy it is possible to recycle at the end of its life…

      We chose blown-in glasswool because it can come virgin, unbonded. Being glass, it does not need any fire retardants and still has good thermal properties. Also, the content of the product we use is 80% made out of recycled beer bottles. For us, clear winner.

      However, we now also offer cellulose and mineral wool.

      Every material has its benefits and negatives but we always assess the situation and suggest what we think is the best choice for the client and their new home.

      Do you have any preferences, Luke?

  • Rob says:

    Great tips. It is very informative post. I would definitely try to follow your tips to live chat. Thanks for sharing this information with us.

  • Jen says:

    I live in Edmonton, Canada where the winter temperatures can dip as low as -30, -35 degrees Celcius (-22 F). I love everything about the Ecokit concept, and am really curious to hear your thoughts about whether the insulation options offered would be sufficient for the temps mentioned. Thanks in advance!

    • Camilla says:

      Hi Jen! Every ecokit home is designed to the site conditions, and we can deal also with such temperatures. Ecokit can be Passive House certified and therefore comfy all year round. I come originally from the Czech Republic, where we can also have around -25 degrees Celsius and yet I have never been so cold as during the winter here, in Melbourne, Australia. Hence the ecokit = comfortable home all year round, tested and proven 🙂

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