Fire authorities refuse to sign off on new building rules for bushfire zones in Victoria because they will put lives at risk.

The long overdue changes are to be implemented next month, but authorities are concerned that cost cutting has been a higher priority than safety in creating the new rules.

The fire authorities say that the new code is flawed because it requires houses to resist lower flame intensity compared to flames of bushfires.

The new code will see restrictions on the type of materials used in construction as well as the way houses are designed.

Victorian Premier John Brumby has said he will not wait for the outcome of a Royal Commission into the Victorian Bushfire disaster to impose the tougher standards.