The insulation materials industry faces a dual challenge: meeting growing thermal performance requirements according to the GEG while reducing carbon footprint over the entire life cycle. Expanded polystyrene (EPS), widely used for its insulation properties (λ = 0.032 to 0.038 W/m·K) and low cost, generates significant volumes of production waste and construction site debris. Austrotherm, an Austrian manufacturer specializing in synthetic insulation materials, has taken a decisive step with the commissioning of a closed-loop recycling facility at its Purbach site, which now processes both manufacturing waste and post-consumer materials.
The technical process: from granulation to reintegration
The facility deployed at Purbach is based on a multi-phase mechanical recycling process. Collected EPS panels—whether from cutting waste or demolition materials—are first shredded to obtain calibrated granules. This granulate then undergoes cleaning and sorting to remove contaminants (adhesives, coatings, membranes). The purified fraction is reintroduced into the expansion process at a controlled proportion, typically between 10 and 30% depending on the final product specifications. This reintegration does not affect essential normative characteristics: bulk density remains compliant with the density classes defined by DIN EN 13163 standard, and measured Lambda values remain unchanged.
Unlike energy recovery processes through incineration, this approach maintains material value and avoids emissions related to combustion. Chemical recycling, still at the pilot stage in the industry, could recover styrene monomers, but remains costly and energy-intensive. Austrotherm's choice for mechanical recycling therefore follows a logic of immediate industrial feasibility.
Environmental balance and CO₂ performance
Mechanical recycling of EPS presents an environmental benefit measured primarily through reduced virgin material consumption. Polystyrene production requires approximately 2.5 to 3.0 kg CO₂ equivalent per kilogram of polymer, according to EPDs published by raw material manufacturers. By substituting 20% of raw material with recycled content, Austrotherm estimates reducing production emissions by approximately 15 to 18% per cubic meter of insulation panel produced. This saving adds to the avoidance of emissions from incineration or landfilling.
The Purbach site currently processes several thousand tons of EPS per year. At full capacity, the facility could recycle up to 8,000 tons annually, representing approximately 10% of the group's production volume. This proportion remains modest on the European EPS market scale, but signals the industry as a whole. Actors such as ROCKWOOL or ISOVER have already integrated high recycling rates into their mineral wool-based products (up to 70% recycled glass for ISOVER), but EPS had so far lagged structurally.
Implications for the value chain: collection and logistics
The economic viability of EPS recycling depends heavily on collection efficiency. Unlike rock wool or glass, EPS has a very low mass-to-volume ratio (typical densities of 15 to 30 kg/m³), making the transport of uncompacted waste costly and inefficient. Austrotherm has therefore established a network of regional collection points equipped with mechanical compactors, which reduce volume by a factor of up to 40. This logistics infrastructure represents a significant investment, but it determines the process's profitability in the medium term.
The model could inspire other manufacturers. The joint project between Austrotherm, PORR, Baumit and ORBIS Development, already discussed in a previous article, aims precisely at testing circularity on real construction sites, with traceability of flows and contractualized material returns. This type of cross-sector collaboration could become an operational standard if regulatory and tax frameworks evolve in favor of material recovery.
Competitive positioning and replication potential
On the European synthetic insulation market, Austrotherm positions itself as a pioneer in industrial EPS recycling. Other actors, particularly in the PIR/PUR insulation segment, are exploring similar paths but face the chemical complexity of cross-linked polyurethane foams, which are more difficult to recycle mechanically. The Saint-Gobain group, through its ISOVER subsidiary, has announced investments in composite panel recycling, particularly those incorporating graphite EPS.
The potential for replication of Austrotherm's process will depend on three factors: the availability of EPS waste deposits (estimated at approximately 300,000 tons per year in Central Europe), the evolution of petroleum-based raw material costs (which make recycling more or less competitive), and regulatory evolution. The ongoing revision of EN 13163 standard could include minimum recycled content requirements, similar to what is already practiced for recycled materials in concrete (DIN EN 206 standard with addition of recycled aggregates).
Prospects: toward a circular economy for synthetic insulation
The Purbach experience could serve as a model for industrializing EPS recycling at the European scale. Comparable initiatives are emerging in Germany and France, notably driven by industry associations such as IVH (Industrieverband Hartschaum). However, the profitability of these facilities remains dependent on public subsidies or incentive mechanisms, such as a tax on landfilling of insulation materials or an extended producer responsibility (EPR) system.
In the medium term, the question will also arise of integrating recycled EPS into products certified for demanding applications, such as passive buildings or KfW Effizienzhaus houses, where each fraction of variation in the Lambda coefficient matters. Austrotherm's initial results show that incorporating 20% recycled content does not affect thermal performance measured according to the guarded hot plate method (ISO 8302), paving the way for unrestricted homologation.
For more information on Austrotherm's commitment to circular construction, consult the manufacturer's official website: www.austrotherm.com.
