How to remove insulation from a house


A well-insulated building can get by with low-temperature heating (30-35 ° C). This offers two major advantages for the heating installation: Less heating energy is lost, especially not along the piping, and the heating can use the renewable energy sources with maximum efficiency, regardless of whether it is the solar heat generated with collectors in winter or the ambient heat produced by a heat pump.

In Switzerland, the average age of buildings is more than 45 years and their lifespan is well over 100 years. However, more than half of the houses are poorly insulated, especially with regard to the walls, roof, floors and windows. Most of the buildings are heated with heating oil. If a boiler is getting old, many homeowners wonder whether they shouldn't choose a more economical and environmentally friendly heating system.

First isolate and then replace the heater

The most efficient measures in terms of energy consumption and environmental protection are the thermal insulation of the building and the replacement of the windows. This is because energy consumption can be reduced much more drastically than with the installation of solar collectors or a heat pump in a poorly insulated building.

Without isolation

This house, whose attic and basement are not heated, is not insulated. It therefore acts like a huge radiator that emits heat to the environment via the outer walls (and windows), the ceiling of the top floor and the floor above the basement ...

Touch the houses and the arrows

Uninhabited attic

If the floor is sealed with a thick layer of insulation (20-25 cm), the upper limit of heat losses can be greatly limited.

If the attic is to be used as a storage space, it is advisable to choose an insulation material that can be laid under the floor (e.g. made of chipboard). You can do this yourself if a few rules are observed that prevent water vapor escaping from the apartment from condensing in the floor and thus leading to moisture damage.

Inhabited attic

Here the thermal insulation is installed under the roof, more precisely under or above the roof joists (in the latter case, the bricks must be removed, which is more expensive). Different insulation techniques are possible depending on the roof structure and cover. As with the walls, an insulation layer 20 to 25 cm thick should also be selected here in order to achieve good efficiency.

Certain rules must be adhered to in order to prevent water vapor from the apartment from condensing in the roof structure and thus causing moisture damage (vapor barrier).

Isolation of the basement ceiling

With a little DIY experience, this job is easy to do. Insulation panels for the ceiling can be glued, screwed on or fixed on wooden slats. If the basement is high, don't skimp on the material thickness: In the rooms above you will have significantly fewer cold feet.

With the thermal insulation of the basement ceiling, energy consumption can be reduced by up to 10%.

Insulation of the inner walls

This is a classic method, but it is not very effective. It has two disadvantages: on the one hand, the interior space becomes smaller, on the other hand, it cannot prevent the radiation effect on the edge of the panels and walls that adjoin the outer wall (= thermal bridges).

Certain rules must be adhered to in order to prevent water vapor from the apartment from condensing in the roof structure and thus causing moisture damage (vapor barrier).

Isolation of the outer walls

In terms of energy savings, this is the best solution because the building is completely wrapped in the insulation layer (15-20 cm). Firstly, there is no longer any direct heat loss through stone slabs and walls, and secondly, the mass of the wall serves as a heat store in winter - and as a cold store in summer.

Several techniques are possible: plaster applied to the insulation or a curtain-type, rear-ventilated facade (VHF).

Isolation of a cold room

An unheated room or a storage room within a building can be insulated from the inside, i.e. the ceiling and walls that come into contact with inhabited rooms. This insulation is not intended to heat the chamber, but rather to prevent the heat from escaping too easily from the adjoining living spaces.

If in winter the temperature of an unheated room is not lower than at least 4 ° C compared to the temperature of the adjacent heated rooms, insulation is not a priority.

Isolation of a cold floor

The floor of a room over a cantilever is often cold because it is in direct contact with the outside air. With external insulation, not only can energy be saved, but thermal comfort can also be gained.

Isolation of double walls

Outer walls are sometimes also made up of two shells: an outer wall made of concrete, a cavity, an inner wall made of narrow bricks: this is a double wall. This was often the case between 1950 and 1970. If the cavity is wider than 3 cm, it can be filled with insulation material (blown insulation materials such as foam, granules, rock wool). To do this, holes are drilled in the walls and the cavity is gradually filled with filler material from bottom to top.

This work is carried out by professionals, especially to prevent problems with wall moisture. You can complete this thermal insulation with an external insulation.

Thermal bridges allow heat to escape easily

The picture shows the facade of an older building in winter. The thermal image shows the thermal bridges and also makes particularly clear the heat losses through the floor and ceiling panels embedded in the walls (horizontal yellow lines).

It is recommended that new buildings and buildings to be renovated be insulated with external insulation - this does not apply to historical facades that are worth protecting as a monument. Because from a thermal point of view, external insulation only has advantages: it keeps the building mass warm in winter, but cool in summer. In this way, it can better buffer the weather-related temperature fluctuations, and you have to resort to the heating (or air conditioning) less quickly. In relation to internal insulation, good external insulation results in fewer problems with condensation of moisture in the insulation material and in the walls (which reduces the effectiveness of the insulation), and above all it prevents heat loss through "thermal bridges".

Thermal bridges are areas in components of a building through which the heat flows away faster to the outside. They are mainly located in the outer area of ​​the building that cannot be insulated by internal insulation, such as the edges of the reinforced ceiling or floor slabs, stair landings or lintels embedded in the wall. A thermal imaging camera is easy to spot on a cold night.

When it comes to thermal insulation, don't skimp on the material thickness

Glass wool, rock wool, wood wool, insulation boards made of Styrofoam, those made of foamed polyurethane, hemp or straw - the insulation materials available on the market have different insulation properties. You can't expect miracles from any material: Even insulation materials with the best thermal resistance must have a thickness of at least 12 cm in order to comply with the MuKEn standards (which corresponds to 18-20 cm glass wool). Contrary to what the advertising promises, thin, reflective multilayer insulation has no effective insulation value.

Only new materials based on airgel (two to three times more insulating than glass wool) and "VIP vacuum insulation panels" (four to six times more insulating than glass wool) currently offer good insulation with low panel thickness. But these materials are still very expensive and not very environmentally friendly. In addition, VIPs may neither be cut nor pierced.

The insulation efficiency can be selected from the various insulation materials according to material thickness, price, service life or environmental compatibility (with regard to production, transport and disposal). But there is simply no such thing as ideal thermal insulation. Insulation materials that are touted as natural (hemp, sheep's wool and wood wool, etc.) are often treated to protect against insect infestation and mold formation as well as with fire retardants. It is best to rely on official standards, not sales specifications.

Green roofs as a natural habitat

It actually goes without saying that the facade and roof (flat or pitched roof) of a building should be insulated. However, walls, floors and ceilings also require thermal insulation, which separate the heated rooms from the unheated ones (garage, attic, cellar) or less heated ones (workshop, storage room, pantry). If it is a flat roof, one can consider "greening" it, that is, it has to be insulated and sealed and covered with a layer of gravel and some organic material. It can then be planted with native wild plants to create dry zones that are becoming increasingly rare in nature. Green roofs not only promote biodiversity within forested areas, but also accommodate animal and plant species at heights that are rare on the ground. Green roofs and solar panels go very well together.

It is very important that one also deals with the "U-value" of the roof, facades and double or triple glazed windows before starting work. The smaller the U-value, the less the building element allows the heat to flow out to the outside during the cold season; and during hot spells it does not allow heat to penetrate the building as well. It is always worth asking yourself whether you cannot achieve a lower U-value than the prescribed one, because this value is directly related to the heating cost bill and the environmental impact (CO2 and air pollutants).

The best insulation: vacuum

Glazing / windows

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