The Victorian Building Authority (VBA) will investigate 170 inner Melbourne buildings to check whether flammable cladding was used in their construction.

Audit notices have been issued to builders and surveyors after cladding imported from China and not tested to Australian standards contributed to November’s blaze at the Lacrosse building in the city’s Docklands.

The material, Alucobest, enabled the fire to race up to the 21st floor from an eighth-floor balcony, where it had been sparked by a cigarette.

The VBA launched an investigation into the Lacrosse building and is trying to identify other buildings using similar cladding.

About 20,000 practitioners have been asked to provide details of buildings they suspect may have used aluminium composite products in non-compliant ways.

Builder LU Simon has already admitted Alucobest was used at the Aura on Flinders apartments in Melbourne’s CBD and Mitcham Village Apartments in suburban Melbourne.

Both have since been deemed fit to occupy.

The Insurance Council of Australia (ICA) told insuranceNEWS.com.au if buildings are found to have used non-compliant materials, the impact on their insurance will depend on specific policies.

FM Global Australian Operations Chief Engineer Andre Mierzwa says voiding the policy is not an option.

“We are not allowed by law to do that,” he told insuranceNEWS.com.au.

“The insurer can change terms and conditions and premium at renewal date, or advise the client they won’t renew coverage. Their broker would need to find another insurer who is willing to take on the risk, which would be rare but possible.”

ICA says many insurers inspect high-rise buildings before agreeing to underwrite them, but they also rely on policyholders’ declarations that a building is fully compliant.