THERMAL INSULATION: HOW TO OPTIMIZE IT?

Feel warm at home? A pleasant feeling which is unfortunately not shared by all people. While some people turn to heating equipment to remedy this discomfort, others undertake thermal insulation work. A more expensive solution but much more effective in the long term. For what? And how can you improve the insulation of your home? we will explain all of this to you in this article.

Why is thermal insulation of your home important?

Thermal insulation brings together all the methods for improving the thermal comfort of a home. This energy renovation guarantees: a uniform temperature inside the home, more efficient ventilation, and a reduction in indoor humidity.

In short, it is as beneficial to the building as it is to the occupants. This is also what ADEME (Ecological Transition Agency) underlines with its 4 good reasons to insulate your home  :

1: more comfort

According to ADEME, 2 out of 3 French people are cold in their homes, even though their heating is on. This feeling of discomfort does not result from a heating problem but from the insulation.

The walls, windows, doors, and roof that shape your home act as barriers against outside air, and by extension cold or heat.

Some homes are designed to be self-regulating. This is the case for passive houses and low-consumption houses. More expensive to build, they are however more economical (15% energy savings for low-consumption houses, between 20 and 30% for a passive house) because they use very efficient insulation materials. Result: the high price is sustainably offset by the savings made over the years.

But not all French houses are lucky enough to be so efficient. Poorly insulated, these components of your home can let this fresh outside air pass through and cool your indoor air. This is what happens to walls that are not insulated, single-glazed windows, doors that have sealing problems, or dilapidated roofs.

Insulating your house therefore allows you to slow down the flow of outside air (fresh and warm) and maintain a comfortable interior temperature. Besides, do you know the ideal interior temperature? Let's take a tour of your home.

2: More energy savings

Never does the expression “throwing money down the drain” take on more meaning than when they are poorly insulated.

Whether you heat with gas, electricity, wood, or oil, you have paid for this energy to power your heating system. Obviously, you prefer that this warm air stays inside. Unfortunately, a poorly insulated house is like a holey Emmental cheese, providing a passage to the outside for hot air.

The parties responsible for heat loss? The roof, walls, ventilation, and thermal bridges.

3: Less Maintenance

Air flows also promote humidity and condensation inside the home. This very common physical phenomenon occurs when we observe a temperature difference between the ambient air and surfaces. It is completely natural and can be explained by several factors:

poor ventilation (stale air loaded with volatile organic compounds and humidity cannot be extracted from the home);

poor insulation (temperature differences favor the appearance of humidity within the home);

daily household activities ( cooking, drying laundry, showering, breathing, etc.);

the weather (rain or winter increases the humidity in the air).

In addition to the health problems it causes (allergies, headaches, coughing fits, sleep disturbances, etc.), humidity can also pose a threat to the stability of the building.

Indeed, molds and fungi stain the surfaces on which they take up residence. Humidity can also degrade paints, as well as floor coverings (parquet, linoleum, laminate), and metal elements, can rust.

The problem can worsen when infiltration and capillary rise (water rising from the ground) attack the structural elements of your home (wooden frame, exterior coatings, lime mortars, permeable stones).

What if you took stock of the humidity in your home?

The humidity diagnosis reveals all the flaws in your home before undertaking renovation work, think about it.

4: More Value

The hunt for thermal strainers is on! Since April 1, 2023, if a home is classified in category F or G following the Energy Performance Diagnosis (DPE), an energy audit must be provided with it (not to be confused with the thermal study ).

Beyond this obligation, a well-insulated house remains a commercial argument for all the reasons mentioned above.

Thermal insulation, from the inside or from the outside?

Overall, you will have two choices available to you to thermally insulate your home: by working inside your home or by modifying the exterior.

Let's quickly look at how these methods work and which parts can be intervened on.

Thermal insulation from the inside

Internal thermal insulation brings together all the methods where the insulation is placed inside the home (in the walls, low floors, attics, roof slopes, etc.).

If we follow the ADEME infographic on heat loss from a house, your efforts should focus primarily on:

the roof ;

the walls ;

the glass walls;

low floors;

thermal bridges.

Insulating the roof from the inside

A little physics lesson is in order. Hot air, lighter than cold air, rises and settles in the attic. If your roof is not airtight enough, the hot air continues its path and leaves your home.

To keep this warm air in your home, you must carry out work to insulate your attic. Two methods can be applied depending on their accessibility. On the roof slopes and On the floor

The method used for insulating roof slopes depends on two parameters: the frame and the available space and can be done in two ways, either by:

the installation of semi-rigid panels;

the installation of rollers;

the blowing of insulation.

This installation will lose a few centimeters of space at the level of the ramps but will leave you sufficient space to set up a comfortable room. A new furnished and insulated room, perfect for enhancing your house or apartment!

When the attic cannot be converted, the best solution is to insulate the floor. Here again, two methods can be used:

the installation of rollers between the joists;

insulation by blowing.

Insulating walls from the inside

In the absence of the roof, which covers the upper part of your home, the walls surround your house. All your rooms can therefore be insulated.

Economically affordable and technically accessible, thermal insulation of walls from the inside comes in two techniques:

installation of insulation by gluing;

the installation of insulation on a frame (metal or wood).

Insulating low floors from the inside

Representing a lower source of energy loss, low floors should not be neglected during your energy renovation work.

Depending on the height between the floor and the ceiling, several solutions are available to you:

insulation from below. This is the simplest method since you can place flexible or rigid insulation depending on the floor;

insulation from above. It involves insulating the floor and covering it with another covering;

insulation between structural elements of the floor.

Insulating glass walls from the inside

Double glazing (two panes of glass separated by an air or gas gap) has not always been the standard for glass walls. It was especially in the 1970s that it began to establish itself in the construction industry before becoming the reference in terms of the insulation of glass walls.

Thermal insulation of windows is strongly recommended if you have purchased a home that still has single-glazed windows (if its construction dates back to before the 1970s). The energy gain is considerable: around 40%!

If your windows are double-glazed, that's a good thing. But you can reinforce the insulation of your glass walls by opting for triple-glazed windows. The difference? It simply has additional glazing and an air gap.

Insulating thermal bridges from the inside

Thermal bridges bother building professionals a lot because they are places that highlight the thermal weaknesses of the home. It is difficult to insulate them effectively since they are located almost everywhere (between the roof and the walls, between the walls and the joinery, between the floor and the walls, etc.).

Thermal bridge breakers ( thin bricks) can plug these gaps, but the best solution to combat them remains to undertake comprehensive renovation work, particularly from the outside.

External thermal insulation

Overall, you can insulate your home from the outside in two places:

your roof;

your walls.

Thermal insulation of the roof from the outside

In exterior roof insulation work, the roof covering is removed to install the insulation either:

in the form of load-bearing roof panels between the rafters;

with a continuous bed of rigid insulation between the frame and the roof (this is called sarking ).

Thermal insulation of walls from the outside

More expensive than the interior method, ITE ( exterior thermal insulation of walls ) has many advantages: very homogeneous insulation, no impact on the passenger compartment surface, and protection against climatic variations.

Three techniques are used for this type of insulation:

insulation with protective cladding;

the installation of coated insulating panels;

the installation of an insulating coating.

5 tips for optimizing the thermal insulation of your home

Now that you have knowledge of all the methods of thermal insulation in your home, here are 5 tips that will help you prioritize and optimize your insulation work  :

insulation first, equipment then;

call on an RGE professional;

find out about prices;

do not neglect ventilation;

adopt a few inexpensive tips.