Based on the polymer polystyrene (PS), Compacform is a thermoplastic with a density ranging from 100 – 400 kg/m3. Compacfoam’s physical structure and chemical composition correspond entirely to that of the well-known expanded polystyrene (EPS , Styropor®), which features closed-cell foam balls of less than 1 mm in diameter that are thermally welded into a compact block at their cell walls, resulting in a massive block. Compacfoam’s material innovation was to improve and extend the performance of this well-established technology, allowing considerably higher densities to be achieved. Compacfoam is a material solution that combines high compressive strength with good heat insulation and lightweight properties. Its elevated stiffness (2 % compression with a working load) and long term stability make Compacfoam a highly suitable product for insulation and lightweight construction applications.