Why choose Avenir Renovations?
Why insulate your home in Leuven today?
In a poorly insulated house, most heat loss occurs through the envelope: roof, walls, floors, and openings.
A heating bill that weighs heavily
Without insulation, the boiler runs longer to compensate for what escapes through the roof and walls. The cost repeats every winter, following the evolution of energy prices.
Insulating means consuming less for the same or better comfort. The savings are even more visible if the house started from a low point.
A lack of comfort
Cold walls, drafts, rooms that are difficult to heat, noise from the street or neighbors: well-installed insulation stabilizes the temperature and also improves acoustics.
In a terraced house, insulating the roof and the floor over the garage is sometimes enough to transform the comfort level on the living floor.
An EPC label that now matters
In Flanders, the buyer of a property rated E or F must achieve a D label within six years. Even without obligation, a poor label weighs on resale value and the attractiveness of a rental property, in a Leuven market where buyers compare certificates.
Insulating remains the basis for any label improvement. It is also the condition for a heat pump to operate under good conditions.
Our insulation solutions in Leuven
Depending on the construction of your home and your goals, several techniques can be combined.
Why call Avenir Renovations to insulate your home in Leuven?
Insulating is not just about adding a material. Each wall is part of a system that must remain healthy.
We examine the roof, walls, floors, joinery, and ventilation, EPC certificate in hand if you have one. The goal is to prioritize the most effective interventions and avoid mistakes such as condensation caused by poorly installed insulation.
Insulation materials chosen according to the wall, available space, and your preferences: mineral wools, wood fiber, cellulose wadding, PIR panels. The thicknesses aim for the performance expected in Flanders today, not those from twenty years ago.
Injection from the outside, blowing in the attic, panels fixed under the basement ceiling: most techniques are carried out without touching the living spaces. When an interior intervention is necessary, the rooms are protected and the site is divided so that you keep a livable space.
What is the cost of insulation in Leuven?
Each technique has its cost, which then varies with the surface area, access, and thickness of insulation. Our home insulation price simulator gives you an initial range. Indicative prices, VAT of 6% included for a property over ten years old.
| Type of work | Factors affecting the price | Indicative price including VAT |
| Roof insulation from the inside | Thickness, type of insulation, board finish | 45 to 85 € / m² |
| Roof insulation from the outside (sarking) | Excluding covering, access, and scaffolding | 120 to 200 € / m² |
| Attic floor insulation | Blowing or panels, circulation path | 20 to 50 € / m² |
| Injection of cavity walls | Cavity width, facade area | 20 to 35 € / m² of facade |
| External insulation with coating | Thickness, finish, scaffolding | 130 to 200 € / m² |
| Internal insulating lining | Available thickness, adjustment of sockets and skirting boards | 60 to 110 € / m² |
| Basement or garage ceiling insulation | Surface area, ducts to work around | 30 to 60 € / m² |
During the visit, the cavity of the walls is inspected through a small opening, the existing insulation thicknesses are measured, and thermal bridges are identified. The estimation follows, wall by wall, with the expected effect on the label.
Procedures and grants for insulating your house in Leuven in 2026
What grant for insulation in Flanders?
Mijn VerbouwPremie for insulating roofs, walls, and floors is no longer accessible, as of March 1, 2026, except for owner-occupiers in income categories 3 and 4. For these households, the conditions and amounts have not changed. For categories 1 and 2, insulation is no longer subsidized by the Region.
Each category of work can only be subsidized once every five years. The application is made online with the final invoice and the technical data sheets of the insulators, which must meet the minimum required performance.
The other financial levers
The reduced VAT of 6% applies to insulation work in a home over ten years old, regardless of income category. Mijn VerbouwLening allows households in categories 2, 3, and 4 to finance the work at a favorable rate. For a property purchased with an E or F label, insulation is also the most direct means of meeting the renovation obligation.
Is a permit required for insulation?
Injecting hollow walls, insulating a roof from the inside, or a basement ceiling does not require permission. External insulation on the street side alters the appearance of the facade: it may require an omgevingsvergunning, and a building listed in the heritage inventory requires prior verification.
The support of the City of Leuven
The City offers free support in energy renovation, with a home visit. Delays can be several months during busy periods: nothing prevents you from requesting our diagnosis and estimate in parallel.
How insulation changes the bill
Savings that depend on the starting point
In a poorly insulated house, the roof and hollow walls significantly reduce heating consumption from the first winter. The further the house started from, the more visible the gain. The EPC certificate issued after work measures the progress, and you are given a numerical estimate for your house during the visit.
An example in a bel-étage in Kessel-Lo
For a bel-étage from 1965 with a roof of sixty square meters, seventy square meters of hollow walls, and a garage ceiling of forty square meters, the budget often ranges from 6,000 to 10,000 euros including VAT. These three items are often enough to gain one to two EPC classes.
Frequently asked questions about insulating a house in Leuven
Does insulation also improve summer comfort?
Yes, especially roof insulation, which slows down the heat accumulated under the tiles. Dense insulators like wood fiber prolong this effect. Combined with external solar protections, insulation keeps the rooms significantly cooler during heatwaves.
How to insulate a solid wall?
In old houses with solid walls, insulation is done from the outside with a coating or cladding, or from the inside with a lining. The interior loses a few centimeters per room but keeps the facade intact, which is important in the historic center.
How long does hollow wall injection take?
One to two days is generally sufficient for a terraced house, depending on the facade area. Technicians drill small holes in the joints, inject the insulation, and then seal with mortar matching the color of the existing joints.
Does insulation cause humidity?
Not if it is properly installed and accompanied by adequate ventilation. Problems arise from a discontinuous vapor barrier, insulation placed against a damp wall, or a house that has become airtight without air renewal. This is what the diagnosis helps to avoid.
Insulate before the next winter
A hollow wall injection takes one or two days, and roof insulation takes one to two weeks. To benefit from the gain as soon as the heating season starts, it is ideal to schedule the work between spring and early autumn.
The on-site diagnosis costs you nothing, and scheduling an appointment can be done with one call.
Agency Avenir
Rénovations
for Insulation work in Leuven
An expert to take charge of your renovation projects and guarantee deadlines, budgets and quality of all services.
