Insulating the attic of your home
The principle of insulating the attic of a house
The loss of heat in a house is most often due to
to poor insulation.
Each part of the house facing the exterior has
a risk of heat loss.
The consequence is ruthless: an over-consumption of energy to heat the home.
It is therefore very important to insulate your house properly.
Roof insulation is the most profitable because it allows for significant energy savings.
Undeveloped attics are a major place of heat loss. Insulating the attic is therefore the first thing to do when you want to save energy.
Simple to implement, the very low cost of the work makes it possible to
a saving of nearly 30% of the energy used to heat your home.
SIMPLICITY OF THE WORK
Attic insulation does not require major work in your home.
Insulation is installed in less than a day.
IMMEDIATE ENERGY SAVINGS
As soon as the attic is insulated, the energy consumption for heating is significantly reduced.
The return on investment is not long in coming.
Attic insulation: how does it work?
How does it work?
The choice of insulation will be made according to the use of the attic space.
In the case of converted attic space, insulation will be done during the conversion by insulating the walls and roof.
In the case of a lost attic, insulation is done by installing insulation on the upper floor of the house.
There are different insulation technologies available. They come in two forms: rolls or flakes. The flakes are dispersed in the smallest corners to avoid thermal bridges.
The insulating materials used have a high thermal resistance.
This is how they retain the heat of the house, not allowing any heat flow (either from the cold outside air or from the heat inside the house) to pass through them.
ADDITIONAL COMFORT IN THE SUMMER PERIOD.
Contrary to what one might think, attic insulation also allows less summer heat to penetrate the house through the roof, provided it is insulated to a very high thickness (more than 40cm) with high-density insulation (light insulation in rolls should therefore be avoided).
Insulation of the attic of your house: the implementation
Mise and oeuvre
Depending on the type of your roof and access to the attic, we will select the type of insulation.
INSULATION IN BLOWERS: These are placed in the attic by a blowing system that will spread it in the smallest interstices over a desired thickness.
However, since flake insulation is very light and volatile, do not hesitate to oversize the thickness to avoid overheating in summer.
This operation is very fast and is carried out by a professional equipped.
INSTALLATION OF THE INSULATION IN ROLLS OR SHEETS :
Rolls or sheets of insulation are placed between the rafters in the case of insulation of converted attics and above and below them.
In the attic, the rolls are usually stapled to the inside wall of the roof or unrolled from the floor.
INSTALLATION BY A PROFESSIONAL
The quality of the installation of an insulator is very important since the finishes are decisive for the efficiency of the insulation.
It is important to check that there are no gaps between the insulations or between the insulation and the rafter. This would generate an air leakage that would divide the thermal resistance by 5.
The superior quality of the insulation cannot compensate for this loss.
That is why, even if the installation of attic insulation could be done by a private individual, the technical competence of a professional will guarantee the thermal efficiency of the insulation work.
How to Choose the Right Insulation for Attic Insulation
There are several types of insulation:
Bulk insulations: Cellulose wadding, rock wool, expanded Perlite.
Insulation in rolls: Expanded polystyrene, glass or rock wool, hemp wool, extruded polystyrene, wood wool, rock wool for flooring, polyurethane.
There are three technical characteristics that should be kept in mind when choosing insulation materials:
Thickness in centimeters:
It is advisable to insulate at least 20 cm thick to obtain a satisfactory level of insulation. The thickness of the insulation will be defined according to the insulation itself. For Cellulose Wadding, it is advisable to insulate on 27cm, against 22.2cm for loose rock wool. For Hemp Wool in rolls it is necessary to insulate 23.4cm against 25cm of wood wool.
Thermal conductivity (W/m.°C)
Insulation materials must have very low thermal conductivity.
The lower the thermal conductivity of a material, the lower its ability to carry heat. This makes your home better insulated.
Thermal resistance (m².°C/W)
Thermal resistance is the result of the performance of the insulation of the house. It is a function of the choice of the insulating material used and the thickness of the insulation.
How much does it cost to insulate the attic of a house?
What is the cost?
INSULATING THE ATTIC SPACE OF YOUR HOME PREVENTS HEAT LOSS AND
THUS REDUCING THE HEATING NEEDS OF THE HOUSE.
Roofing losses can result in a 30% waste of heating energy. Its financial impact on a household’s energy budget is therefore just as important as the choice of heating method itself.
Insulating the attic = energy savings A LOW INVESTMENT COMPARES WITH THE ENERGY SAVINGS REALIZED
The amount of work will depend on the choice of materials and its thickness.
Count about :
– 11 euros/m² for Rock Wool in bulk on 22cm thick,
– 15 euros/m² for Cellulose Wadding on 27 cm thickness recommended,
– 30 euros/m² for Hemp Wool in roll on 23cm thick,
– 45 euros/m² for Wool on 25 cm thick.
Be careful, mineral wools (rock wool) can be quite irritating.
It is therefore not recommended to use it if you plan to pierce the ceilings to integrate light spots for example.
Tax credit for attic insulation A REDUCED INVESTMENT THANKS TO THE TAX CREDIT.
The French state wishes to help develop the use of renewable energies.
15% tax credit for interior works whose purpose is to produce heat.
Attention only heat pumps with a COP greater than or equal to 3.3 are eligible for the tax credit.
On what amount of expenses does the tax credit apply?
The tax credit covers the price of equipment and materials, excluding labor, meeting the characteristics.
What is the amount of expenses eligible for the tax credit?
For the same taxpayer and the same dwelling, the amount of expenses eligible for the tax credit may not exceed, for a period of five consecutive years between January 1, 2010 and December 31, 2015, the sum of € 8,000 for a single person, widow or divorced and € 16,000 for a couple subject to joint taxation. This sum is increased by €400 per dependant within the meaning of Articles 196 to 196B.
To find out your rights to the tax credit, you are advised to refer to the provisions of article 200 quater of the General Tax Code.
For the application of this measure, it is strongly recommended to refer to :
The website www.impots.gouv.fr (page on the tax credit)
Article 200 quater of the General Tax Code, Article 90 of the 2005 Finance Act, Article 83 of the 2006 Finance Act, Article 109 of the 2009 Finance Act and Article 80 of the 2010 Finance Act.
The tax instructions 5B-26-05, 5B-17-06 and 5B-17-07
The decrees of February 9, 2005, December 12, 2005 and November 13, 2007 issued for the application of articles 200 quater and 200 quater A of the general tax code relating to capital expenditure on the main dwelling and amending annex IV to this code
Sections 81 to 83 of the 2012 Finance Act
Financial aid for attic insulation from AIDES REGIONALES, DEPARTMENTAL, and ANAH.
Some regions, town halls or the ANAH also subsidize the installation of photovoltaic panels by granting financial aid. Find out more directly from these administrations or from your ESPACE INFO ENERGIE.
VAT reduced for attic insulation VAT REDUCED TO 7% FOR LIVINGS OVER TWO YEARS.
AN INVESTMENT THAT QUICKLY PAYS FOR ITSELF THANKS TO THE ENERGY SAVINGS MADE:
You reduce your energy consumption for heating your home. This can represent several hundred euros per year.
Attic insulation: environmental impact
THE HUNT FOR WASTE
By insulating the attic of your home, you limit heat loss from your home.
Your heating needs will be reduced as a result.
A good insulation is the guarantee of the control of its energy consumption.
The energy saved in this way is as much energy to produce and as much greenhouse gas avoided.
The environmental impact is then immediate and lasting for many years.
BACK TO NATURE
Many manufacturers now offer completely ecological insulation materials made from natural products such as sheep wool, wood, etc…
Renewable materials with very low environmental impact, a way to become a little more Eco-Citizen.