Polyurethane foam cladding

There are a number of suppliers - a web search will bring up some such as:

http://www.thermotec.com.au/cms/index.php

There are other suppliers in yellow pages too. This is magic stuff and works quite well. Render finish needs a special sealer that ensures the bond between the render and the foam and most use a 'system' that has a special render mix too.

I have a colleague who has built a number of house with 40mm foam base and rendered exterior surface over the last several years and the owners are very happy. It should be well within DYI too although getting the material might be tougher.

nuplex are a sydney based supplier/ installer and also try unitex but these guys will charge premium $$$

http://www.nuplexconstruction.com.au/?q=node/33

there are small renderers out there who supply & install this stuff much cheaper than these bigger companies