Insulation is essential for the comfort of both our garments and our homes.
Faced with environmental challenges and the need to improve the energy efficiency of our buildings, sheep’s wool, renowned for its thermal and acoustic performance, is a material that is returning to the forefront of eco-construction projects.
Used for centuries for its natural insulating properties, wool is a renewable and locally available fibre. We explore the qualities of wool, the benefits of its use in construction and its role in the sector’s ecological transition.
The natural insulating properties of sheep’s wool
Wool is a natural fibre, produced all year round by sheep using a few simple ingredients: water, air, grass and sun. It’s a natural, renewable insulator with remarkable thermal and acoustic performance.
The curly, scaly structure of its fibre creates pockets of air that limit heat exchange, acting as a thermal barrier, but also an acoustic barrier by trapping sound waves.
In addition to its thermal capacity, sheep’s wool is distinguished by its ability to absorb up to 30% of its weight in water without settling or losing its insulating capacity.
The insulating qualities of sheep’s wool have been used in housing for thousands of years, as demonstrated by the felt-covered yurts of the Mongols.
The ideal wool for building insulation
The thermal performance of wool reduces heat transfer between the walls of homes. This ability to regulate indoor temperature reduces the need for heating in winter and air conditioning in summer. As a sound insulator, it also promotes a quieter, more comfortable indoor environment.
One of the little-known advantages of sheep’s wool is its natural resistance to fire. Unlike some synthetic insulation materials, which ignite quickly and give off toxic fumes, sheep’s wool has a high ignition point, generally around 560°C. It does not melt under the effect of heat, does not give off toxic fumes and forms a carbonised crust that limits the spread of flames in structures.
Wool’s ability to absorb up to a third of its weight in water without losing its insulating qualities makes it an excellent hygroscopic regulator, helping to stabilise the humidity of indoor air.
Although it is resistant to rodents, it must be protected against moths. Treatments such as boron salt can be used in buildings.
A solution to the challenges facing buildings
Faced with environmental challenges and increasing demands for energy efficiency in our buildings, sheep’s wool is emerging as a sustainable and responsible solution.
Thanks to its exceptional thermal properties, sheep’s wool stands out as an effective alternative to traditional insulation materials, at a time when the energy transition and reducing the carbon footprint of buildings are priorities.
It is also part of a circular economy approach, as it uses a renewable and biodegradable resource that is available locally. Finally, unlike oil-derived materials, it will not generate polluting waste like microplastics at the end of its life.
The result of a natural process, sheep’s wool is a renewable resource that plays an essential role in the environmental transition of the building sector. Although its initial cost may be slightly higher than that of conventional insulation, its benefits in terms of energy efficiency, safety and interior well-being make it a worthwhile investment over the long term. By incorporating natural insulation in new buildings and renovations, it is possible to reconcile comfort, sustainability and respect for the environment.
