Perth home builder Builton Group was trading while insolvent for several months last year before administrators were called in, but was given a clean bill of health by WA's Building Commission.

The commission audited Builton in November and the company went into administration in January, stopping work on more than 100 building sites around Perth, owing millions of dollars to creditors and leaving dozens of staff unemployed. Director of compliance Sandy Randall said the commission would try to impose disciplinary action…