The right choice of insulation materials and techniques has the potential to reduce energy consumption and make the building harmless for health. Among the green materials used for insulation today are sheep’s wool, cotton, aerogel, Icynene, cellulose. Although the cost of sustainable materials sometimes is higher than traditional fiberglass, they prove to be more cost-effective and beneficial in the long run.

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Reducing energy consumption and carbon emission are the most important factors in selecting insulation. The right insulation can reduce an energy bill on average by 30%. Inefficient insulation can damage the environment. Many houses were built with harmful health fiberglass insulation for over a century. Now the demand for eco-materials is rapidly growing. In terms of thermal insulation, the material is sustainable in case it does not contain any toxic components, at least partly recyclable, and preferably produced locally. Production methods for insulation manufacturing and their impact on the environment are also important in selecting a sustainable material.


Other than the material selection, numerous other factors have an impact on the insulation, such as the thickness of the external wall, floor and ceiling area, natural light penetration. No matter how great the materials used for the insulation, they will not perform well, if they are not installed properly. Compression and air leakage allow heat to escape and become a reason for poor insulation. 


Green home insulation materials

  • Sheep’s wool. Just like the sheep survive in the harshest environment, the insulation material used from its wool provides an exceptional thermal barrier. The compressed wool fibers form numerous air pockets, which help the material trap air, remain breathable, and regulate humidity. Moist wool generates heat and prevents condensation. Sheep’s wool keeps the house cool in summer and warm in winter. The material is fire-resistant. 

  • Cotton/denim. Cotton has some of the important qualities of fiberglass, such as the possibility to be rolled into batts and the same R-value. However, the cotton’s price over twice higher in comparison to fiberglass can be explained by the formaldehyde absence, insect repellence, ability to absorb moisture. When treated with a borate solution, the material becomes fire-resistant. Cotton is an eco-friendly and renewable resource. 

  • Aerogel. A material produced by removing the fluid from silica under high pressure and temperature, the aerogel is what remains as a result of this process. The material consists of 90% air and serves as perfect insulation with R-10.03 per inch thickness. 

  • Icynene. A spray foam made from castor oil expanding about 100 times its volume, sealing air leaks tightly, and muffling the noise.

  • Rigid polystyrene. Although polystyrene is made from plastic, which is not exactly a green material, it does help to save lots of energy and keep the building sustainable. Polystyrene can also be recycled. 

  • Cellulose. Cellulose appears to be one of the most practical and sustainable insulation choices. Made of recycled newspaper, the material is resistant to air leaks and free from toxins.


Understanding the necessity of achieving sustainability with all the techniques and engineering processes of the construction makes architects and designers introduce new approaches to maximization of the thermal insulation in the architecture. The following thermal insulation methods that meet sustainable objectives are worth mentioning:

  • ventilated facade creating a chimney effect between the insulation and construction envelope, which helps maintain temperature and air conditioning;

  • cold roofs is a technology reducing the roof’s temperature by up to 70% and keeping the balance between interior and exterior temperature.

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