An overview of Government requirements.
Currently throughout all states of Aus. there are minimum insulation requirements for all new homes under the 'Building Code of Australia' . The situation is at present complicated by various state requirements that over-ride the BCA.
Builders can meet the necessary requirements by the 'deemed to comply' provisions of the BCA or by providing an Energy Rating that shows compliance with state requirements.
For example in Vic. a level of 5 Stars is required; in SA a level of 4 Stars.
A new release of the BCA due in 2006 will evidently include a requirement for a blanket 5 Star.
Currently Energy Raters employ various versions of software developed by the CSIRO with Victoria & SA predominantly using 'FirstRate' and NSW 'NatHers'.
Trials are currently being conducted by Energy Raters Australia wide on a refined programme called 'AccuRate' with a commercial version to be released later this year after the trials are completed.
From a home owners perspective it should be understood that these regulatory requirements are minimum requirements and being an important component of a homes design the correct levels of insulation for your particular home in your particular location should be studied and thoroughly researched.
As an example R2.0 ceiling insulation may be sufficient to meet requirements and be installed by your Builder. In many areas R3.0 can be purchased for the same price with added heating / cooling benefits. In Vic there is a moratorium on insulating timber floors until 2006 but will this effect your resale value 10 years down the track compared to a home that has floor insulation installed ?
At the end of the day, home owners should research what is best for there interests and not rely solely on the 'regulations' as currently there is an amount of confusion by the Government bodies who set the regulations as to the best approach.
As individual situations do vary I'd be happy to answer specific questions [as far as possible] through this Forum.