A development that could sustainably change the insulation material market in Central Europe: Austrotherm has established a recycling process for expanded polystyrene (EPS) at its Purbach location that returns both production waste and demolition material to the manufacturing process. The process addresses two central challenges in the industry: circular management of petrochemical insulation materials in accordance with EU taxonomy requirements and cost optimization in an increasingly regulated building insulation market.
Technical Basis of the Recycling Process
The process implemented by Austrotherm is based on multi-stage processing of EPS material. Scrap and production residues, which were previously thermally recycled, undergo a mechanical shredding and cleaning process. The granulate obtained is then – after checking bulk density and grain size distribution – fed into new production in defined proportions. Crucial for standards compliance is that the mechanical properties of the final product must meet the requirements of DIN EN 13163 for thermal insulation made from expanded polystyrene. Particularly critical are the compressive stress at 10 percent compression and thermal conductivity, expressed by the lambda value (λ).
Relevant for planners and processors: The reuse of EPS recyclate must not affect the declaration of the insulation material class according to DIN 4108-10. Austrotherm states that through controlled admixture, the required λ values of 0.031 to 0.035 W/(m·K) – depending on the product line – are maintained. Furthermore, fire class E according to DIN EN 13501-1 for standard EPS remains unchanged, since the recyclate does not introduce new flame retardants but maintains the existing HBCD-free formulation.
Circular Economy and EPD Accounting
The integration of recycled material into EPS production has direct impacts on the environmental product declaration (EPD) of the insulation material. According to DIN EN 15804 requirements, all material flows – including recyclate portions – must be recorded in the life cycle assessment. By returning production waste, Austrotherm can reduce the proportion of primary raw materials, which is reflected in a lower GWP value (Global Warming Potential). Concretely, this means: Every ton of recycled EPS that is not thermally recycled avoids the new production of styrene monomer – an energy-intensive process with high CO₂ emissions.
Compared to other insulation manufacturers that rely on mineral wool or renewable raw materials – such as ROCKWOOL with stone wool or STEICO with wood fiber insulation – Austrotherm positions itself as a provider of a closed loop for petrochemical insulation materials. For architects and building owners certifying according to DGNB or BREEAM criteria, this increases the attractiveness of EPS, provided that the EPD data are updated accordingly.
Economic Classification: Cost Efficiency and Market Pressure
The decision for an in-house recycling process is also a response to volatile raw material prices. Styrene, the main component of EPS, is subject to considerable price fluctuations as an oil derivative. By returning up to 15 percent recyclate – a common proportion in the industry for standards-compliant EPS – Austrotherm can reduce dependence on spot markets and stabilize production costs. This is particularly relevant in the context of increasing requirements for energy renovation under the Building Energy Act (GEG), where insulation material prices per cubic meter play a decisive role.
A comparison with other industry initiatives shows: Saint-Gobain through the ISOVER brand has also increased investment in glass wool recycling in recent years, while Austrotherm has already established a recycling facility in full operation for EPS insulation material. The parallelism of these developments indicates a systematic change: circular economy is evolving from a regulatory requirement to an economic necessity.
Standards Compliance and Approval Issues
For the use of recycled EPS in thermal insulation applications, compliance with DIN EN 13163 is mandatory. Austrotherm must demonstrate that the reuse of material has no negative effects on long-term durability – particularly with regard to moisture absorption, dimensional stability and aging behavior. In-house production control (WPK) according to DIN EN 13172 is the central instrument here. Additionally, for applications in thermal insulation composite systems (ETICS), general building authority approvals (abZ) are required, which must explicitly specify the recyclate content.
Another aspect: The use of demolition material – that is, EPS from demolished buildings – requires additional quality assurance. Contamination from dirt, aging or HBCD-containing flame retardants (in products before 2016) must be excluded. Austrotherm states that currently primarily production waste is recycled; the integration of post-consumer material is still in the testing phase. Here lies a decisive difference to fiber cement recycling, as Etex and Heidelberg Materials are already implementing on an industrial scale.
Outlook: Scaling and Industry Impact
The establishment of the recycling process in Purbach is one component of a larger strategy. Austrotherm operates additional locations in Central and Eastern Europe and has already announced a second insulation plant in Romania. The question will be whether the recycling process will be transferred to these locations and whether other EPS manufacturers will follow suit. For the insulation market, this could mean: EPS is increasingly perceived as a recycled building material, which strengthens its position against mineral wool and wood fiber insulation in the context of circular building.
In the future, planners should also consider the recyclate content in material specifications – not only from sustainability considerations, but also because this is increasingly required in public tenders. The development at Austrotherm shows: circular economy in the insulation sector is technically feasible, standards-compliant, and economically viable.
