Good points: Excellent insulators and can be fitted into narrow spaces where others could not.
Suitable for cavity wall insulation.
Bad points: The most energy intensive insulating materials to produce, contains chemicals high in (HFC’s) the greenhouse gases produces toxic fumes when burnt. Not so good at fitting between rafters.

Polystyrene insulation > Extruded and Expanded (Ecogo rating 2 star)

Good points: Can be made from recycled materials, long lasting, resistant to moisture, air movement, rot and compression.
Bad points: Made from petrochemicals so produce toxic fumes and solvent emissions when burnt. Deteriorates over time as gases release. Extruded polystyrene requires more processing and uses double the energy to make than expanded.

Mineral wool Insulation  (Ecogo rating 3 star)

Good points: Sometimes made from 100% recycled materials or melted down volcanic rocks or steel slag, its fireproof inexpensive and available everywhere.
Bad points: Takes a lot of energy to produce, a mask is needed for installation due to the dust and performance may diminish as fibres get flattened over time or if exposed to wet.

Glass Fibre Insulation (Ecogo rating 3 star)

Good points: Commonly available, made from melted glass which can be recycled. Very cheap
Bad points: Takes a lot of energy to produce. Releases solvent emissions or (VOC’s). Non biodegradable. Dust masks and suits are vital when installing to protect from dust particles. Flattens over time and doesn’t work when wet.

Sheep’s wool insulation (Ecogo rating 4 star)

Good points: Excellent insulating properties, safe, easy to install and resistant to moisture and fire, minimum energy to produce.
Bad points: four times more expensive than the commonly used glass fibre.

Cellulose insulation / Recycled newspapers insulation (Ecogo rating 5 star)

Good points: Excellent use of waste newspaper, Effective insulator and good at getting into awkward areas as the material is blown in with a machine, Good sound proofing qualities, comparable prices with synthetic materials.
Bad points: The powder has to be installed by a professional, isn’t suitable for cavity walls and doesn’t work when wet.

Flax and Hemp insulation (Ecogo rating 5 star)

Good points: Natural plant fibres that are available in batts and rolls and typically contain borates that acts as a fungicide, insecticide and fire retardant. Easy to install. Both materials have low embodied energy and are often combined in the same product. Half the price of sheep’s wool.
Bad points: Not widely available but becoming more popular as demand increases.

Cotton insulation (Ecogo rating 4 star if produced from recycled textiles and clothing)

Good points: If recycled cotton is used it’s an excellent use of waste materials, easy to install.
Bad points: Not widely available. Concerns over the high use of pesticides used in growing cotton makes it a poor choice if the cotton doesn’t come from recycled sources.

Straw insulation (Ecogo rating 4 star)

Good points: Available in many forms, some are made from agricultural waste making it an excellent use of materials, can double as partition walls due to their robust nature, and therefore are a must see for anyone considering low-impact dwellings.
Bad points: Not widely available, may need chemical treatment to protect against fire & pests.

Cork insulation (Ecogo rating 3 star)

Good points: A range of cork tiles available in differing thickness and colours, although the natural coloration is by far the most popular. Extremely lightweight and sustainably harvested from a renewable source, cork is a great material for interior wall surfacing. Some of the cork produced is impregnated with a resinous binder to improve the durability of the material and this has an interesting impact on the overall aesthetic.