Whether your attic is inhabited or lost, it is essential to insulate it properly, because nearly 30% of the heat escapes through your roof. Good insulation will allow you to make real savings and increase comfort in your home.
Simple to perform, the insulation can differ according to each house, the use of your attic or the materials used. In addition, if this investment represents a cost, many opportunities for bonuses and reductions are available to you. Follow our guide!
Properly insulating the attic inside and/or outside allows you to limit heat loss in winter and keep your home cool in summer. An interesting advantage that will make you realize significant savings, knowing that the roof concentrates 25 to 30% of the losses!
For this, insulating materials with high thermal resistance and low thermal conductivity are used. Thus, the heat, which has more difficulty passing through them, stays inside your house in winter and does not penetrate in summer to keep your home cool and pleasant. Insulation is therefore not only a matter of savings, but also of comfort.
To choose the right insulation, it all depends on the purpose of your attic. You will not insulate lost attics, convertible attics and inhabited attics in the same way.
This option is the most common, the simplest and the least expensive since it takes an average of 3000 euros for 100 m². It differs depending on the use of your attic.
Insulating your lost attic is essential to prevent heat from rising and storing it in winter. You would unnecessarily heat an empty room to the detriment of the ones you occupy. To do this, you have three options:insulation by laying or unrolling insulation, by blowing or by spreading.
If you can easily access your attic, insulate the floor using insulating panels or rolls very simply. Mineral wool is an interesting and widespread solution.
Insulation by blowing is done by depositing insulation on the floor, to a height of 30 cm. This quick and economical solution uses wood fibre, cellulose wadding or even mineral wool. These materials do not absorb moisture and are good insulators, especially for low ceiling heights.
Finally, you can opt for insulation by spreading. Very simple, this technique aims to manually spread the insulation on the surfaces to be insulated.
Whatever the solution chosen, it is advisable to call in a professional. Since 2007, the insulation of lost attics has indeed been governed by obligations and minimum performance requirements established by the Regulations for Existing Buildings.
The development of the attic is ideal for enlarging the surface of your home, from the inside or from the outside.
The insulation under crawling consists in applying the panels or rolls of insulation on the frame. If nearly three quarters of French homes are equipped with glass wool, an effective and inexpensive material, there are many other quality insulators of vegetable, mineral or animal origin.
The thickness of the insulation blanket should not be less than 30 cm to be effective, even if it means cutting back slightly on the living area; you won't regret using it. This less expensive solution than exterior insulation will cost you between 30 and 45 euros per m².
Exterior insulation is intended above all for new constructions and major renovations. This technique is ideal for properly insulating the attic without carrying out interior work or cutting into the living space, so it is the perfect solution for houses with beautiful frames and exposed beams. In addition, the outer insulation allows continuous protection and also isolates much better noise.
This form of isolation, also called sarking , consists of placing the layer of insulation between the cover and the batten. This technique is increasingly in demand due to the strengthening of thermal regulations, the space saving it allows and the insulating performance it guarantees in terms of sound and heat. Although more expensive, it saves you the interior work to arrange and decorate the attic after the insulation has been installed. Count on average between 40 and 60 euros per m².
To complete the insulation of finished attics and save more money, also insulate the floor as you would for lost attics. Whether they are inhabited or used for storage, their floor insulation will bring more comfort to your entire home.
If the insulation of your attic represents a substantial investment cost – more or less important depending on the formula chosen – you will then realize significant savings. In a well-insulated home, heat loss is reduced and you need less heating for your comfort; your heating bill can be reduced by a third! Faced with the increase in the cost of different energies, these savings are undeniably advantageous and quickly observable.
Insulating your attic will cost you between 5,000 and 10,000 euros, depending on the surface to be covered, the configuration of your home, the materials used and the installation method chosen. Finally, don't forget that you can benefit from attractive bonuses and discounts.
Any homeowner can benefit from financial aid for carrying out attic insulation work:
Educate yourself and do free studies online to find out what discounts you can claim.
The installation of the insulation creates an airtight layer intended to prevent the heat from passing through. However, it is important that your roof breathes to avoid accumulating water vapor. The latter generates humidity and mould, a risk of rotting of the wood and impacts the effectiveness of the insulation. Consequently, plan a VMC or double flow type ventilation system.
Attic insulation requires perfect coverage and finishes. Any forgotten space creates a thermal bridge and lets the heat escape. Calling on a professional is the best way to obtain a quality result and to benefit from guarantees. You can accompany the work with a maintenance contract to ensure the quality of your attic on a regular basis and to prevent any damage due to infiltration.
