According to the UK Department of Energy and Climate Change in October 2012 in their estimates of home insulation levels, there are 26.9 million homes in the UK. They conclude that 66% of homes with lofts have loft insulation of 125mm or more, 69% of homes with cavity walls have cavity wall insulation, and just 2% of homes with solid walls have solid wall insulation. These figures have been improving, with 320,000 more homes having installed loft insulation and 150,000 having installed cavity wall insulation between July and October last year [1]. Despite this there is clearly room for more homes to improve insulation, and with recycling and reuse at the forefront of green thinking, recycled insulation products should not be ignored.
Why is home insulation important?
The benefits of effective home insulation are simple. The less heat that is lost when it is cold outside and the less heat that is absorbed when it is warm outside, will mean less energy will be required by heating and cooling systems and therefore energy bills will be less, thus saving money and reducing the carbon footprint. The importance of insulation becomes apparent when you take into account that somewhere in the region of 50% to 70% of the energy used in a household is used for either heating or cooling [2].
Alternative materials and their advantages
Many common insulation products are already produced using recycled materials. For example loft and cavity insulation can often be found to be made of recycled news paper. The market for recycled insulation has been on the up for the past decade, and many manufacturers now offer a range of products that not only better man made synthetics in terms of green credentials but also in terms of performance. The following list provides an overview of some of the natural materials available to be used as home insulation and their respective advantages. All have the advantage of being from sustainable sources.
Sheep’s wool
∙ Wool is classed as a hygroscopic fibre and therefore can absorb moisture, in fact more than any other natural fibre meaning its insulation properties do not vary with changing humidity unlike some fibre glass products [3].
∙ The high elasticity of wool fibres means that over time it will not settle, and therefore no performance will be lost.
∙ Has a very high fire resistance, it will extinguish itself if it is set on fire.
∙ It is estimated to use less than 15% of the energy used to produce man made synthetics such as glass fibre insulation.
∙ It repays energy costs approximately five times sooner.
∙ Wool can absorb and breakdown various harmful airborne pollutants such as formaldehyde and nitrogen dioxide [4].
Straw
∙ Can be used as part of the building’s structure and therefore can reduce the amount of timber required by half.
∙ If the straw bales are compressed and sealed with plaster it proves to be fire resistant.
∙Very low embodied energy, cheap to use and readily available.
Hemp
∙ Naturally resistant to fungus and insects.
∙ Much like wool it is a breathable material and therefore is able to absorb and release moisture to help regulate internal humidity.
∙ Insect and vermin resistant.
Cork
∙ Naturally resistant to rotting.
∙ Does not support combustion.
Cotton
∙ Can be sourced from the plant or alternatively from recycled clothes such as denim.
∙ Similar insulation properties to fibreglass but does not contain formaldehyde, a substance linked with some types of cancer.
∙ Breathable, like hemp and wool.
∙Insect repellent.
These materials are just some of the recyclable and sustainable materials that can be used for home insulation. On top of the given advantages, all the above have shown to be effective insulators, having an insulation value above that of current building regulations and in many cases having insulation properties greater than that of man made synthetics. These natural materials not only help reduce C02 production by reducing energy usage in households, but many in fact absorb C02 before their life as insulation. For example, hemp which as a plant absorbs C02, has been proven that for every cubic meter of hemp insulation produced, roughly 13 kg of C02 is absorbed [5].
With the housing sector accounting for somewhere in the region of a third of the country’s carbon footprint according to the Department of Energy and Climate Change [6], effective home insulation should not be disregarded by home owners and the government. This combined with rising energy costs makes these sustainable alternatives to home insulation a serious consideration.
[1]https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/49403/7154-stat-release-est-home-ins-oct-2012.pdf
[2] http://www.ornl.gov/sci/roofs+walls/insulation/ins_01.html
[3] http://www.thermafleece.com/wonders-wool
[4] http://www.sheepwoolinsulation.ie/why_wool/
[5] http://www.ecologicalbuildingsystems.com/products/natural-insulation/
[6]https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/48195/3224-great-britains-housing-energy-fact-file-2011.pdf
