EPiC database - Structural insulated panel (SIP)

This material is part of the free Environmental Performance in Construction (EPiC) Database. The EPiC Database contains embodied environmental flow coefficients for 250+ construction materials using a comprehensive hybrid life cycle inventory approach.

Structural insulated panels, often referred to as SIPs, are a composite product containing an outer skin and inner core. As their name suggest, they are typically used as a structural element for low-rise buildings.

Outer layers of oriented strand board (OSB) are glued to an insulating core made from expanded polystyrene (EPS). The core gives the panels good thermal properties while the outer skins provide a durable, aesthetic finish. Alternative core materials, such as extruded polystyrene (XPS) or rigid polyurethane (PU) foam and outer skin materials, such as plywood or fibre cement sheet can also be used.

SIPs can be used as wall or roof panels and are mainly used in domestic construction. They are very lightweight and thus easy to move. The panels come in a range of thicknesses ranging from 100 to 300 mm. Typical panel dimensions are 300, 600, 900 and 1 200 mm wide and 2.4, 2.7 and 3 m long. Openings for windows and doors are cut out of panels during manufacture. Panels are connected onsite using splines with cavities cut into the core for electrical and plumbing services.