This free insulation thing has caused a number of house fires.
Unqualified installers putting insulation over people's downlights.
Like Trevor, we'd have to take out the 30 year old insulation and pay for around 20sq.
That's if you can get the batts. I read of one installer spotting a load being delivered to Bunnings, walking in and telling them he'd buy the whole load. They just transferred it to his truck.