SIPs are lightweight building panels that combine two high-density facings bonded to either side of a low density polymeric core. Typical materials include Oriented Strand board (OSB) or Cement Bonded Particleboard (CPB) for the facings, and foamed polyurethane (PUR) or Expanded Polystyrene (EPS) for the core. In the UK these panels are predominantly used as internal and external walls in dwelling and light-industrial construction of up to three storeys. In some applications the panels are also used for the roofing structure.
The building system was first introduced in the US in the 1950s, and today SIPs are established in housing construction as main loadbearing members throughout the building, i.e. as floors, roofs and walls (internal and external).