Why choose Avenir Renovations?
Why insulate walls from the inside?
Interior insulation (ITI) is an effective and accessible solution to improve the energy efficiency of a building, especially in the context of renovations on existing constructions.
A quick and measurable energy gain
By insulating your walls from the inside, you immediately reduce heat loss in winter, and improve thermal regulation in summer. This results in a significant reduction in your heating consumption, and thus your energy bills.
An ideal solution for buildings with listed or protected facades
Interior insulation is often the only solution compatible with buildings whose facade cannot be modified, whether for architectural, aesthetic reasons, or due to strict urban planning regulations.
Better acoustic comfort
In addition to thermal performance, ITI helps to reduce external noise (traffic, neighbors, etc.) thanks to the sound-absorbing properties of the insulating materials used.
Interior wall insulation techniques
There are several methods to insulate walls from the inside. The choice depends on the configuration of the home, the desired performance level, and your budget.
What insulators for an effective ITI?
The chosen materials directly influence the level of thermal, acoustic insulation and overall comfort.
- Glass wool / rock wool: excellent value for money, very good thermal and acoustic insulation
- Wood fiber: natural insulator, effective in winter and summer, regulates humidity
- Expanded polystyrene (EPS): lightweight, economical, but less effective acoustically
- Polyurethane (PUR): very good thermal resistance with low thickness
- Aerogel or vacuum insulators: very high performance, but high cost, reserved for specific cases
What is the price for interior wall insulation in Belgium?
The cost of ITI depends on the material used, the area to be covered, the targeted performance level, and the technical constraints of the building (corner adjustments, treatment of thermal bridges, connections...).
Factors influencing the price
- Type of insulation and thickness
- Installation technique (framework, glued panels, lining)
- Accessories (vapor barrier, cladding, profiles)
- Additional work (removal of existing coverings, adjustment of outlets, filling)
- Complexity of the room (ceiling height, angles, curved walls...)
Average prices observed in Belgium
| Type of intervention | Average price including tax per m² (installation included) |
| ITI under framework + glass wool | 45 to 65 € / m² |
| ITI with glued rigid panels (EPS) | 40 to 55 € / m² |
| ITI in wood fiber | 55 to 75 € / m² |
| ITI with technical insulators (PUR, aerogel) | 80 to 120 € / m² |
| Preparatory work (removal, corrections) | 10 to 20 € / m² |
| Finishes for ready-to-paint plasterboards | 15 to 25 € / m² |
A detailed and free estimate is always prepared by us after a technical visit, to best estimate the total cost of the project.
The advantages of ITI with Avenir Rénovations Belgium
Choosing Avenir Rénovations Belgium means benefiting from:
- A comprehensive support: thermal study, material selection, installation, finishing
- A single point of contact to simplify project management
- Qualified craftsmen, certified and trained to Belgian standards
- A fast, clean, and controlled site
- A complete grant file prepared with you
Can we benefit from grants for ITI in Belgium?
Yes. Insulating interior walls is part of the work eligible for regional grants within the framework of an energy renovation project.
- Wallonia: Housing Grant (based on area, performance, and income)
- Brussels: Renovation Grant (based on insulation level and EPC)
- Flanders: Mijn Renovation Grant (based on income and insulated area)
General conditions:
- Insulation of a minimum thickness (generally ≥ 10 cm)
- Thermal resistance R ≥ 3.5 m²K/W
- Carried out by a certified professional
- Site registration and compliance with technical standards
We help you compile your complete file, with all the necessary certificates.
Get your free quote for insulating your walls from the inside
Do you want to reduce your heating bills, improve your thermal comfort, and enhance your property value? Insulating walls from the inside is an effective and quick solution to implement, eligible for financial aid in Belgium.
Contact Avenir Rénovations Belgium today to schedule a free visit and receive your no-obligation quote.
FAQ – Interior Wall Insulation (ITI) and Energy Renovation in Belgium
Is interior wall insulation effective in energy renovation?
Yes. ITI is a recognized and effective method for improving the thermal performance of a home. It can reduce heat loss by up to 25% when walls are poorly or not insulated. By addressing the interior surfaces, it increases comfort, decreases energy consumption, and improves the energy performance certificate (EPC) of the building.
What are the most commonly used materials for ITI in Belgium?
The most common materials are:
- Glass or rock wool, for their thermal and acoustic efficiency
- Expanded polystyrene (EPS), for small budgets
- Wood fiber, for natural and breathable insulation
- Polyurethane (PUR), for high performance with low thickness
Each material has advantages depending on your priorities (ecology, budget, available space, humidity...).
Can you obtain a regional grant for ITI work?
Yes. Interior wall insulation is eligible for energy renovation grants in the three Regions:
- Wallonia: Housing Grant
- Brussels-Capital: Renovation
- Flanders: Mijn Verbouwpremie
The amounts depend on the household income, the insulated area, and the thermal performance achieved (thermal resistance R ≥ 3.5 m²K/W). Avenir Rénovations Belgium will assist you in the grant application process.
Is there a significant loss of space with ITI?
Yes, but it remains moderate. On average, an ITI requires between 10 and 15 cm of thickness per insulated wall (framework + insulation + finish). This may slightly reduce the living space, but the gain in thermal comfort and energy consumption more than compensates for this loss. Some technical solutions exist to limit the bulk (high-performance thin insulations).
Is ITI suitable for all types of buildings?
Yes, it is often the preferred solution in older homes where external insulation is impossible (listed facades, terraced houses, urban planning constraints). ITI is suitable for both single-family homes and apartments and can be applied room by room according to your budget.
