Insurance companies are charging up to $1700 more than each other for home and contents policies covering identical houses in the same suburb, prompting calls for greater transparency.

But the industry argues the variations are due to different types of coverage and are evidence of healthy competition.

Research by the Emergency Services Levy Insurance Monitor, which surveyed premiums across 11 suburbs, found an average variation of $1100 between insurers for "basic home and contents polices".

In Medlow Bath, the highest quote of $2794 was from GIO, two-and-a-half times larger than the lowest quote of $1106 from Coles.