Attic Insulation in Charleroi

Our attic insulation services

–  Thermal diagnosis of the attic before intervention

–  Insulation of lost attics by blowing

–  Insulation of convertible attics from the inside

–  Treatment of singular points (trapdoor, ducts, conduits)

–  Ventilation control after insulation installation

Process of an attic insulation project

The initial diagnosis measures the thickness of existing insulation, identifies thermal bridges, and checks the condition of the framework before recommending an appropriate insulation technique.

For lost attics, blowing mineral wool or cellulose remains the fastest and most effective technique, with a project often completed in a single full day.

For convertible attics or those intended to be converted, insulation from the inside between rafters or under slopes requires more time and precision in installation, especially around existing roof windows.

Lost attics or convertible attics: two different logics

A lost attic, uninhabitable and often cluttered, is treated simply by blowing insulation onto the floor. The technique is quick, economical, and does not require any modification to the existing framework.

A convertible attic or one that has already been converted requires a different approach: insulation is installed between rafters or under slopes, with a carefully installed vapor barrier to avoid any risk of condensation within the roof thickness.

The choice between the two techniques also depends on the owner's future projects. An attic currently lost but intended to be converted in a few years benefits from being insulated directly under slopes, to avoid having to redo the work later and waste an initial investment.

Attic insulation in Charleroi's buildings

Worker houses made of brick, very common in several sections of Charleroi, often feature a simple framework, sloping with two sides, with a lost attic easily accessible by a trapdoor or a narrow staircase.

More recent constructions on the outskirts, with industrial-style frameworks, sometimes require special attention around the points where the wood intersects, where thermal bridges are more frequent than in a traditional framework, and where insulation must be blown carefully to fill every gap.

Grants and VAT in Wallonia

Attic insulation is eligible for Walloon housing grants, with amounts varying according to household income and the thickness of insulation installed, within the limits set by the Walloon Region.

The 6% VAT applies to these works in a home over ten years old, provided that the corresponding mention appears on the invoice from the registered contractor.

Attic insulation and overall energy renovation

Attic insulation often fits into a larger energy renovation project, alongside the replacement of windows or the boiler. Addressing this aspect first properly sizes the actual needs of the rest of the heating system.

The reform of housing grants planned for October 1, 2026, will further favor applications combining several insulation aspects over isolated interventions, a factor to anticipate for homeowners planning their work over several years rather than in urgency.

Thickness, construction time and ventilation

A thickness of 30 to 40 centimeters of blown wool is generally recommended to achieve optimal thermal performance in the Belgian climate, with its humid winters and marked temperature variations. For lost attics by blowing, a single day of work is usually sufficient; convertible attics require more time, often two to four days depending on the area to be treated. Good ventilation remains necessary after insulation to avoid condensation under the insulation, a point systematically checked after each project.

Efficiency, installation and side effects

Insulating the attic is an effective and quick first step to reduce bills, but a global diagnosis remains useful to identify other complementary areas of heat loss, such as walls or old frames. Insulating your own attic is technically possible for simple lost attics, but professional installation ensures a uniform thickness and access to Walloon grants, which often require an invoice from a registered contractor. A thick thermal insulation also dampens some of the outside noise, particularly rain on the roof, a secondary comfort often appreciated. The blowing technique does not affect the structure of the existing framework; only a prior diagnosis identifies any structural problems to be addressed separately before insulation.

Insulate your attic before next winter

A poorly insulated attic is felt as soon as the first chills arrive. The free thermal diagnosis quickly identifies weak points before proposing a costed solution tailored to each roof configuration.

From the worker housing of Jumet to the more recent constructions of Gosselies or Ransart, the diagnostic method remains the same, only the chosen technical solution varies according to the encountered framework.

A project planned before the cold season allows for immediate thermal gain from the first winter following the work, without waiting for a new heating season.

Insulating the attic remains, in the vast majority of energy renovation cases handled by our teams, the area that offers the best ratio between the cost of work and the observed reduction in the annual heating bill, regardless of the neighborhood or municipality concerned.