One of the difficulties with ensuring adequately insulation of a home is that there is always a difference between the 'theoretical' R values associated with installing insulation and the actual valuesw once installed. Workmanship on site often does not install insulation as recommended and anticipated R values can be compromised. Spray in foam insulation is a product that has been available in the US for a while which does away with these on site issues.
Finally it is available in Australia. Icynene and Insulfoam solutions are two companies which supply and install this product. The foam is air blown, contains no CFC's, no formaldehyde, no HCFC's and no hydrocarbons.
The foam is blown into wall, ceiling and floor cavities, expands and creates an impervious insulation barrier. Over it's lifetime it will not collapse or fall out like many other insulation products and provides a much better seal against air leakage.
This is a great product that will have many applications and should help improve the quality of insulation used in our houses.