Well-insulated homes better conserve heat and use less energy, helping to cut energy bills and carbon emissions. But not all insulation is created equally.
The most commonly used insulation materials are petroleum-based. Whilst helping to cut demand for energy, these fossil fuel-based materials have high levels of embodied carbon. Petroleum products also contain benzene, styrene, or chlorofluorocarbons - all of which are harmful to the environment.
There is another way. Our built environment should embody the very highest environmental standards in all phases of its material life. The use of natural materials is key to realising this ambition.
Bio-based insulation materials have grown in popularity over recent years. These cleaner, greener materials have been shown to trap heat more effectively, improve air quality and reduce the risk of damp.
German manufacturer Gutex, for example, produces insulation panels using recycled wood chips from sustainably managed forests. The result is a carbon-negative product - with more carbon absorbed during the trees’ growth and its use as an insulating material saving more carbon than emitted during manufacture.
Another surprising alternative originates from hemp plants. Hempcrete is made by mixing a pulp of the plants’ stem with a natural cement. This can then be cast into blocks or around a frame and used to insulate a building or create non-load bearing walls.
Hempcrete has the advantage of being hygroscopic, meaning that it absorbs and diffuses moisture, helping to cut the risk of damp. Some suggest the material is also carbon negative because of the high levels of carbon absorbed during the plants’ fast growth. Like many bio-based materials, it is also fire, rot, and pest-resistant.
Restrictions on hemp farming, however, have limited its commercial viability. The government should cut the red tape holding farmers back, support the industry, and encourage the wider use of sustainable materials like hempcrete.
Of course, we cannot and should not stop the use of petroleum-based insulation materials overnight. Good home insulation helps households to cut both their energy bills and carbon footprint. We should, however, think more carefully about the type of materials we use for insulation.
Bio-based products are often just as effective, if not more so, than their petroleum-based competitors and emit less carbon during manufacturing. The government should encourage their use to help the UK meet its environmental targets and boost British businesses.
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