Roof
roof pitch
Drempel
Flat roof
Upper floor slab
Solid ceiling
timber-beamed ceiling
Nail binder
Attic conversion
External wall
Façade
Partition joint in a house
cellar wall
Ground floor
cellar ceiling
Stairway to the cellar
Solid ceiling
Cap ceiling
Timber joist floor/cavity
Special components
Roller shutter boxes fitted into house walls before 1975 are, in most cases, not insulated. This means that the thermal break between the interior and the externally ventilated roller shutter box consists of a 4–5 mm thick plywood panel (plus wallpaper or paint). Although the uninsulated surface area of a single roller shutter box is relatively small, the total heat loss from a residential property through all its uninsulated roller shutter boxes can be relatively high. The consequences: high heating costs, a risk of mould and reduced comfort.
However, if the roller shutter boxes are no longer in use, it is possible to remove the roller shutters completely, seal the outer gap between the window and the external wall, and then have the roller shutter box filled with blow-in insulation. In this process, flakes of insulation material are blown airtight into the cavities of the roller shutter box via a hose using a blow-in machine.
Alternatively, it is also possible to pack the roller shutter box yourself using loose-fill or mat insulation (DIY). This measure is virtually free of charge (very low material costs)
Additional tip: The openings for the roller shutter belt must be sealed once the work is complete.
The entire space of the former roller shutter is utilised.
All the benefits at a glance
Improved thermal insulation: If the so-called heat transfer coefficient (U-value) of the box was previously approx. 5 W/(m²K) (watts per square metre and Kelvin), the insulation work can reduce this to approx. 0.2 W/(m²K). This represents a thermal improvement of up to 95 per cent for the roller shutter box.
Lower heating costs: This measure can reduce the building’s heating costs by up to 5 per cent.
Further benefits:
- Draughts are eliminated
- Comfort is enhanced due to higher temperatures on the inside surfaces of the external walls
- Mould growth is prevented, as the inside surfaces of the roller shutter boxes become warmer and therefore drier
- CO₂ emissions are reduced
- The procedure is minimally invasive
Costs/cost-effectiveness: Depending on the level of difficulty and the labour required by the insulation blowing contractor, the cost is approximately €100 per unit. The payback period is between 4 and 6 years. If you carry out the work yourself, the measure pays for itself in just one year!
Financial assistance: This measure alone is not eligible for funding. However, as part of an energy-efficient window refurbishment, the replacement of roller shutter boxes with electrically operated roller shutters is eligible for up to 20 per cent funding as an ancillary measure.
Can I carry out the insulation myself? The blow-in insulation can only be carried out by a specialist contractor, as they have the necessary equipment (particularly a blow-in machine). However, you are welcome to carry out preparatory and auxiliary work yourself, thereby reducing the expected costs. You can fill the empty boxes with mat insulation yourself.