What is the point of a natural insulation?
Natural or ecological, what difference?
How to know if it is really efficient?
What are the labels or certifications worth?
What is on the market?
Where do I find them?
How to put it and what finishes?
By isolating "green", am I entitled to help?

What is the point of a natural insulation?

30% of the heat of a home escapes through the roof , 20% through the walls. Applying natural insulation saves heating costs . In addition, it requires little energy for its manufacture, emits neither dust nor toxic gas during combustion or degradation, is pleasant to ask and respects health. But it is 20 to 30% more expensive than traditional insulation.

Natural or ecological, what difference?

Natural insulators are of animal or vegetable origin and do not normally contain any synthetic products. But natural does not mean ecological. Ecological insulators are also derived from animal or plant raw materials that are renewable and recyclable. In addition, they are manufactured locally to limit the ecological footprint due to transportation and contain no adjuvant or toxic substance (volatile organic compounds, VOCs) for health.

How to know if it is really efficient?

We must rely on the coefficient of thermal conductivity called lambda . Expressed in W / m ° C (watt per meter and per degree Celsius or Kelvin), it must be mentioned on the insulation. The lower the value, the more insulating the material . Thus, the feather has a coefficient of 0.033 W / m ° C, more efficient than hemp with its 0.040 W / m ° C.

What are the labels or certifications worth?

The certification Acermi (Association for the certification of insulating materials), marked on the packaging, gives the technical and qualitative characteristics of the traditional, natural and ecological products available. The NF Environnement mark and the European Ecolabel guarantee products that have a lesser impact on the environment.

What is on the market?

► Of animal origin ...
● Pen . Blend of washed and treated feathers (70%), polyester (20%) and wool (10%). In semi-rigid panels or rolls.
Asset: repels rodents, regulates moisture.
For: attics, roofs, walls, floors.
Price: from 15 to 20 € / m2.

● Sheep wool ... and ewes . Washed, treated against mites. In rolls.
Asset: Can be compressed to insulate irregular frames.
For: attics, floors.
Price: from 10 to 15 € / m2.

► Of vegetal origin ...

● Cellulose wadding . From the recycling of unstained paper. In bulk or panels.
Asset: excellent sound insulation.
For: floors, walls.
Price: from 5 to 25 € / m2.

● Liège . From the bark of the cork oak, rot-proof. In panels.
Asset: resists moisture better.
For: cellars, bathrooms, kitchens.
Price: from 8 to 30 € / m2.

● Cotton wool . From washed, milled and treated cotton fibers against molds, fungi, insects, fire, etc. In bulk, panels or rolls.
Asset: very good thermal performance.
For: attics, partitions.
Price: from 15 to 20 € / m2.

● Wood fiber . Sawmills and untreated logs. In panels.
Asset: great resistance to aging.
For: partitions, roofs, floors.
Price: from 8 to 25 € / m2.

● Linen felt . Short fibers not used by the textile industry, thermolated to polyesters (15%). In panels or rolls.
Asset: absorbs 10 times more water than glass wool without deteriorating.
For: walls, roofs.
Price: from 10 to 15 € / m2.

● Hemp wool . Renewable raw material. In rolls, flexible panels or blocks.
Asset: easy to install and free of dust.
For: floors, walls, partitions, roofs or attics.
Price: from 10 to 15 € / m2.

Where do I find them?

In specialized stores (Well-being materials, www.bienetremateriaux.com ), on the Internet ( www.eco-logis.com ). They are more and more present at wholesalers such as Point P, Networks pro ... and they also make a great breakthrough in DIY (Castorama, Leroy-Merlin).

How to put it and what finishes?

Depending on whether it is in panels , rolls or bulk, whether it is supported by a partition or used as a filler, the insulation can be stapled, glued, screwed, but also blown or injected . And depending on the type of insulation chosen (cellulose wadding, linen felt ...), we can apply siding (plasterboard) which will receive a layer of paint or a wallpaper. The wood fiber accepts a lime finish (white or tinted). Cork can be left as is or painted.

By isolating "green", am I entitled to help?

The work performed by a professional benefit from a VAT reduced to 5.5% . Some insulation materials are eligible for a tax credit at a rate of 25% . This rate is raised to 40% under the dual condition that these facilities are placed in a dwelling completed before 1/1/1977 and that their installation is carried out no later than December 31 of the second year following that of the acquisition. housing. But this tax credit only concerns the development of principal residences and the expenses paid between January 1, 2006 and December 31, 2009. As for the green loan, or eco-loan, at 0% launched in January, it will not cover insulation costs only if these are accompanied by other work (change of boiler ...).