Builder urgently required: Gold Coast

Builders don't do it in general and there's no licensing requirement other than electrical safety  prior to installation that I'm aware of.

You' re better to use experienced insulation companies. They are familiar with the safety issues to staff and hazards of material located around down lights, electrical fittings and flues.

Ask to see a copy of their workers comp and public liability insurances also warranties etc. 

Your insulation supplier should be able to recommend a competent installer.

http://www.deir.qld.gov.au/workplace/publications/alerts/insulation_install/index.htm