BASF's Neopor foam insulates modern passive houses in Switzerland

Passive houses rely to a large extent on minimizing heat loss through the use highly efficient thermal insulation. The masonry walls of the Rothenburg passive houses are clad with Neopor foam.

Sarnafil (Sarnen, Switzerland), part of the Sarna Group, moulds the black beads of EPS into silver–grey Neopor insulation board, which is then supplied to sister company Sarna-Granol, a maker of exterior insulation and finishing systems. Unlike conventional thermal insulation, the silver–grey Neopor contains infrared absorbers and reflectors that reduce the foam's thermal conductivity. As a result, Neopor insulation board is up to 20 percent thinner than classic expanded polystyrene board having the same level of insulation performance.

And since less material is required, costs and resources are saved. One square metre of 10-cm-thick Neopor board, for example, can save 1200 litres of heating oil over a 50-year period. The 15-cm-thick masonry of the loft houses is clad with a 30-cm layer of Neopor, while 24-cm layer is sufficient for the more compact villette buildings.