Insulating Concrete Formwork (ICF) is a proprietary formwork system for concrete that is left in place to come part of the building.

ICF systems have been available in New Zealand for the last 30 years and during that time have been increasingly used for both commercial and residential construction.

ICF construction has been used for some 50 years in Europe, where concrete residential construction is quite common.

Block systems are widely available in New Zealand. Plank and panel systems are available internationally but not currently in New Zealand.

The forms are typically made of expanded polystyrene, a closed cell polymer.

The reinforced concrete core provides all the structural capacity of the wall.

The main advantages of these systems are:

• Excellent insulation properties
• Low levels of air infiltration
• Blocks are easy to lay and fill
• Relatively easy to run services concealed in polystyrene layer. This is true of both new construction and refitting work
• Long life expectancy