Natural and ecological insulation materials are derived from fauna or flora and have zero or almost zero impact on the environment. However, it will be necessary to assess their carbon footprint over the entire life cycle of the material from its seed, its collection or its extraction. What’s more, their sound and/or thermal insulating properties are widely recognized and no longer need to be demonstrated. So why hesitate? Here is a presentation of these eco-responsible materials for home insulation.
Hemp is an annual herbaceous plant that belongs to the Cannabaceae family. The multiple use made of this plant in our daily life is quite remarkable. It is used for the design of fabrics, in construction, in cosmetics, in the manufacture of tiles, that of ropes, in stationery, in animal and human food as well, and also in sound and heat insulation.
Surprisingly, the Latin name for hemp is Cannabis. If it is indeed the same kind of plant as that used to designate “cannabis” with psychoactive properties, hemp used as an industrial material has a THC level of less than 0.2%. Make no mistake then, industrial hemp does not present any health hazard.
Its advantages are multiple, as are its uses. The plant can be grown anywhere in the world, adapting to any type of soil and climate (between 7 and 30°C). It requires very little water so even its cultivation is ecological. It also acts for the environment by structuring the soil. Thus, 1 hectare of hemp crop fixes 15 tons of CO2 during its photosynthesis. It is one of the best natural insulating alternatives.
Its insulating power is undeniable. Hemp can be used for roof, wall or floor insulation. Widely used for thermal insulation, it also offers good sound insulation performance. Finally, it is 100% recyclable, and resists rodents and mold without treatment. Its fibers have no allergenic or irritant properties. Its only downside: sensitivity to humidity, which can be countered by the application of a vapor barrier.
Cellulose wadding is obtained from recycled newsprint. The paper is ground, and the wadding undergoes treatments, obviously flame retardant since it is made from paper, but also antifungal and insecticide. To do this, it incorporates additives such as boron salt. Its thermo-acoustic insulating power is very efficient, its manufacture is ecological, and its price remains reasonable because of its composition.
Mainly used for the insulation of lost attics, it is then propelled by a blower, which allows it to cover an entire surface uniformly and effortlessly, avoiding thermal bridges. It is also found in panels, where it is then bound by 15% recycled polyester fibers. Its downside? It tends to flatten out over time. To counter this phenomenon, the thickness of the projected layer or of the panels will be increased.
The wood wool is made from recycled softwood offcuts from PEFC-certified coniferous forests. Its insulating power is undeniable, mainly in summer when it retains heat to keep the interior cool. It is said to have a high thermal phase shift power. Why choose it? Because it is a renewable and available material, with low gray energy consumption, which includes all the energy expenditure and consumption necessary for the creation of a product, its production, its machining, its transport, its distribution, storage, marketing, use, maintenance and finally recycling at the end of its life.
The duck feather
This insulation is actually 70% duck feathers, 10% sheep’s wool, and 20% synthetic fibers to ensure sufficient consistency and density. More used in bedding, the duck feather diversifies its use. Better sound than heat insulator, it is sensitive to water but retains its properties after drying. Low in embodied energy, non-allergenic and easily recyclable, this insulation has remarkable qualities. Its downside: it remains very sensitive to fire, and must be covered with a siding and kept away from sources of heat. It will be used mainly for the insulation of non-habitable attics or under floating floors.
Its best asset: its high density which makes it an insulator that is very resistant to humidity and pests. In addition, it absorbs heat to maintain comfort in summer. It will mainly be found in the form of rigid panels, but also exists in granules. Relatively expensive, it is produced from quality oak. 100% natural, renewable and without the addition of binders since it is agglomerated thanks to suberin, which is a sap naturally present in cork, it is one of the best thermal and sound insulators on the market.
Used for a long time, sheep’s wool no longer has to convince of its insulating power. It regulates the ambient humidity and is capable of absorbing up to 30% of its weight in water, but it is not recommended in water features. However, it must undergo treatment to protect it, in particular from fire and parasites. The use of a vapor barrier remains mandatory for use as home insulation. It will be found more often used in altitude dwellings.
Preferred for exterior insulation work, wheat straw is perfectly resistant to temperature variations and can last a hundred years without difficulty. It will mainly be used in rural areas, close to its place of production. Contrary to what one might think, straw bale insulation is particularly fire resistant. It is done on a particular type of dwelling having an adapted wooden frame that can receive the bales protected from humidity, to be extremely effective in terms of thermal and sound insulation.
Originally from Europe, flax is a plant grown solely for its fibres. In insulation, it is rarely used alone, but generally combined with hemp or sheep wool or even cotton. It will be found presented in the form of panels or rolls, for a rather simple use. Its elastic fibers give it a high power of sound insulation.
Better known in the textile industry, cotton wool has a strong insulating power. Its fibrous texture, often associated with linen, offers very interesting acoustic insulation. Cotton wool regulates the humidity level of the ambient air in the home, without losing its performance. Cotton wool is generally found in panels or in bulk, to be thrown into lost attics.
Insulation: Aid for renovation
Faced with the scale of legislative changes to reduce our collective carbon footprint, and aim for an ecological and energy transition in all areas, the State has set up financial aid to follow this ecological and sustainable revolution. To renew an aging housing stock and fight against energy sieves by transforming them into healthy and comfortable housing, insulation is part of the renovation work supported by the State.
- The zero rate eco loan : It helps to finance the materials and the installation by a recognized professional guarantor of the environment (RGE);
- MaPrimeRenov’ : It replaces the energy transition tax credit. It is grantable under conditions of resources;
- Reduced VAT : The State reduces VAT to 5.5% instead of 20% for work to improve energy performance.
Private sector energy providers are also investing in the green revolution by offering a Energy bonus. Financed in part by Energy Saving Certificates, this bonus is open to everyone, regardless of resources.