The best thermal insulation solutions
Priority targets: walls and attics
The attic and walls of a home are the nerve centers of thermal insulation. In the event of a defective thermal insulation, the attic can represent up to a third of the heat losses, and the walls up to 25%. The choice of insulating materials is one of the key factors in limiting these losses. From this perspective, in recent years, “ecomaterials” have been very successful. This neologism stemming from the trend towards sustainable development covers all the materials known for their very low carbon footprint, making it possible to fight effectively against greenhouse gas emissions.
Very often of plant origin, these ecomaterials are sometimes combined with an economic interest, due to their abundance and / or their ease of use. Many ecomaterials are used in thermal insulation, intensively or even privately. Hemp, almost relegated to the oblivion of history by the Industrial Revolution, has made a comeback in recent years. Cellulose wadding from newspapers, straw or even sheep's wool are very effective insulators for attics. Other eco-materials still remain in childhood despite their recognized insulating qualities, such as duck feather.
Thermal insulation from the outside or from the inside?
In the specific case of thermal renovation of walls, two possibilities coexist; Thermal Insulation from the Interior (ITI), or Thermal Insulation from the Exterior (ITE). In both cases, it is a question of limiting the thermal losses of the walls, by using one or the other most appropriate method. The ITI represents the simplest solution, most often less expensive than the ITE, and particularly suitable for new buildings which must obey the strict thermal requirements of the RT2012 law.
However, the ITE represents the most effective solution, making it possible to create a real thermal envelope of the building, and to fight effectively against losses. This technique also offers the advantage of neither reducing the living area, nor disturbing the occupants during the work. The ITE also offers the possibility of covering the thermal insulation with a decorative layer (wood, stone, facing plaster, etc.)
Insulate windows and floors
Windows and floors represent the other potential sources of heat loss, from 10 to 15% for the former, and from 7 to 10% for the latter. For windows, double glazing constitutes a minimum to reduce heat loss, which can be further improved by the use of double glazing with reinforced insulation (VIR) or triple glazing. The other essential element of window insulation is the supporting structure. PVC remains the most effective insulation, followed by the more expensive but aesthetic wood and aluminum. A combination of wood and aluminum constitutes the excellence of thermal insulation for window structures.
Soils are often neglected in ecological thermal optimization work, but are nevertheless among the potential sources of loss of a house, in the order of 7 to 10%. In the case of a new house, the ideal is to think about insulating the ground first, in order to avoid later complications once the house is completed. With regard to already completed houses, the insulation of the floors depends directly on the structure of the floor. If the slab rests directly on the earth, a thick layer of insulation may be necessary (15 to 20 cm). The presence of a cellar facilitates the work, naturally constituting a relative thermal insulation thanks to the void separating the slab from the ground. The insulation layer can thus be reduced to 5 or 10 centimeters. An “eco-material” such as cork, which is very light and hydrophobic, represents an excellent choice of thermal insulation for floors.