Jacqui Kelly could do nothing but watch in horror as her house and worldly possessions burnt to the ground on Saturday.

The Brisbane doctor's home was one of three houses reduced to rubble at the weekend on Evelyn Street in Grange. 

Dr Kelly said the blaze left her family with nothing but the clothes on their backs and what was left in the car.

Only later, after checking her home and contents insurance policy, did she discover that most of their lost possessions were not covered.

"The fact that everything we own has gone is just a bit too much.

"Check your insurance policies because I don't want to cry, but I set mine way too low."

Underinsurance common

Finder insurance expert Tim Bennett said more home owners like Dr Kelly were becoming underinsured, often without realising it.

Mr Bennett said the surge in construction costs had meant homes were costlier to replace, meaning some home owners were no longer fully covered on their current plans.

Additionally, he said home owners typically accumulated items over time, but often did not know their value for insurance purposes when the moment arrived.

A Finder survey in April found 17 per cent of Australians who needed insurance cover in the past three years were either underinsured or completely uninsured, including 4 per cent of home insurance policyholders.

Mr Bennett said the rising cost of living also meant more home owners were choosing to reduce or drop their coverage altogether.

He said it was worthwhile for home owners to check their insurance plans to see whether they were still covered, or whether it was more than they could afford.

Fire being investigated

Queensland Fire and Emergency Services Superintendent Paul Durston said two firefighters had been released from hospital following the Grange fire.

He said one had burns to his arms while the other had suffered from heat stroke while battling the blaze.