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Wednesday, October 20, 2010

NEWSFLASH - R2.5 to fit inside a 90mm Stud Wall

Over the last couple of years, I have spoken to many people who have found it difficult to find wall insulation batts of R2.5 to fit inside a 90mm stud wall.
Recently, I came across an email update from The Insulation Council of Australia and New Zealand (ICANZ). The members are Bradford and Fletcher insulation. Fletcher has just come out with these great pink batts products of R2.5 and R2.7 that can fit inside a 90mm stud wall. You can visit their website for more information
When it comes to energy rating and assessment, additional wall insulation can make a huge difference and save on other material and labour costs on site to comply. I recently rated this large double-storey house of approximately 45 sq/m for a volume builder. The house (depicted below) has a large number of windows and I found it difficult to achieve 5 stars compliance.
Drawing: courtesy of Simonds Homes, used by permission.
The table below outlines our findings:

Ceiling Insulation
Wall Insulation
Energy Rating Efficiency
1st trial
R3.5 for upper floor
Standard insulation throughout the house. Ceiling insulation only for upper floor
2nd trial
R3.5 per floor
A significant increase for energy rating efficiency. Ceiling insulation per each floor would be required, adding additional material and labour costs. However, this cost is minimal in comparison to double-glazing or treated glazing.
3rd trial
R3.5 for upper floor
A sufficient increase for energy rating efficiency to comply. Ceiling insulation only for upper floor. The only additional cost is to upgrade the wall insulation from R2.0 to R2.5. This is a minor cost increase in comparison to the 2nd trial.

As you can see from the above trials, R2.5 for wall insulation can be very effective for compliance, whether to current regulations for 5 stars or for upcoming regulations, 6 stars from May 2011. 
What are your thoughts on this one?
Karim Ghobrial