A development that could accelerate the retrofit market: ISOVER (Saint-Gobain) has introduced two new blow-in insulation materials based on mineral wool called Topdec and Integra. Both systems address a critical challenge in energy-efficient retrofitting: the quick and cost-effective insulation of hard-to-access cavities in existing buildings. While conventional insulation systems often require the dismantling of façade or roof structures, blow-in methods allow application without major interventions to the building fabric.
Topdec is designed for insulating top-floor ceilings and unfinished attics. The material is blown onto the ceiling mechanically and, according to the manufacturer, achieves a homogeneous layer thickness that guarantees a lambda value in the range of 0.035 to 0.040 W/(m·K) even on uneven substrates. For planners, code-compliant installation according to DIN 4108-10 is essential: the loosely applied insulation must be protected against swirling from air movements, achieved through appropriate covers or ballast plates. The advantage over sheet-form insulation lies in the seamless application, which minimizes thermal bridges.
Integra, on the other hand, is designed for insulating roof slopes, wall and ceiling constructions. By mechanically blowing into existing cavities between rafters or stud framing, even complex geometries can be insulated without dismantling. The bulk density is approximately 30 to 50 kg/m³, enabling an optimal balance between insulation performance and installation speed. For fire classification according to DIN EN 13501-1, ISOVER specifies class A1 – non-combustible, a significant advantage over organic blow-in insulation materials such as cellulose.
The market relevance is immediate: Germany has approximately 19 million single and two-family houses, most of which were built before 1979 and have inadequate energy insulation. The new systems are likely to be of particular interest to energy consultants and retrofit specialists implementing projects under the Federal Funding for Efficient Buildings (BEG) program. Installation speed is crucial for cost-effectiveness: blow-in insulation reduces construction time costs by 30 to 50 percent compared to conventional systems. Whether Topdec and Integra have an EPD that transparently discloses recyclability and CO₂ footprint remains unclear from the current manufacturer information – an aspect that is becoming increasingly relevant for assessment according to DGNB criteria.
