Some people are looking for eco-friendly loft insulation, and one of those products is sheep wool. It is used to make loft insulation rolls that are similar to mineral wool fiber and is 20% more efficient. This means that you can use 225 mm of wool to replace 270 mm of fiberglass. Additionally, it is non-irritating, and is claimed to absorb moisture when it is humid and release moisture when it’s dry, which can go further to keep temperatures consistent in a home or building. It is too pricey for many people, though it is longer lasting.