After inspecting thousands of home ceiling with thermal imaging camera I am probably the most qualified person to declare that ceiling down lights are the biggest cause of thermally defective ceilings. Why? because ceiling insulation is simply ripped off around down lights , almost never fitted and replaced. Consequently insulated ceilings are like thermal leaking buckets, leaking heat out in winter and gaining heat in summer:
I think that the Federal Government could have had a greater environmental impact by simply banning down lights than shovelling billions into disastrous pink batt scheme.
For more photos of thermally defective ceilings: www.insulationinspector.com.au