When Is Old Insulation -  Negligible Effectiveness?

Officially the Government states you are only eligible for the $1600 Insulation Rebate if you ;

"Don't already have ceiling insulation or have ceiling insulation that is deemed as having 
negligible effectiveness (an R-value of 0.5 or less)"

The difficulty for you and even the Insulation Installers is determining whether the effectiveness of your home's insulation falls below the  R-Value mark of 0.5.

"R-Values" - are a simply a measure of how effective insulation is in blocking the transfer of heat - however R-values are measured in labs by scientists not in a roofs by installers. 

The government, however is relying on the experience of insulation installers to determine whether existing insulation is deemed negligible or not. To meet the exemption for "Negligible Effectiveness" you will need obtain quotes from at least 2 registered installers that both deem your insulation is of negligible effectiveness.

Given the minimum R - Value for most homes is at least an R - Value 3 you could imagine that an insulation that is has a an R-Value of 0.5 would be in an extremely poor state. Given the risk to installers to lose their registration status with the Government they understandably will be reluctant to assess your insulation as negligible effectiveness unless they truly believe your insulation is!

As an indication only - Insulation may be assessed as having an R-Value of 0.5 or less if the ;

• Insulation batts or loose fill is Less than 2.5cm thick (not reflective)
  
• Gaps between batts or loose fill and ceiling joists is generally 5cm or more
  
• Insulation batts or loose fill is severely water damaged
  
• Loose fill has blown away and less than 2.5cm thick in majority of ceiling space

As the criteria for negligible effectiveness is extremely low many installers are unlikely to assess your homes insulation as of negligible effectiveness unless they truly believe it meets the governments criteria. Additionally some installers - given the high cost of visiting your house, may charge you a visit fee to assess your insulation's effectiveness.

Important Note: Even if you do obtain 2 quotes from registered installers that both deem your insulation is of negligible effectiveness the cost of removal is not covered by the $1600 insulation rebate - you will need to pay the removal of existing insulation yourself.