insulated concrete formwork

Insulated concrete formwork (ICF) is available in several different systems. 

A key benefit is that as the formwork is left in place, a full insulation system is provided that has already been made airtight by the concrete.  Using ICF means that there are no constraints on the style or shape of the walls.  Like SIPs it's possible to clad the walls in many different materials to create a modern or traditional design.

Concrete however is not the most environmentally-friendly material.  However, modern concrete production can use waste materials such as blast furnace slag to replace up to 75% of cement content.