Chase the Strata Manager or the Builder?

Our building is just over 6 years old and fast approaching the conclusion of the builder's warranty period. In August 2010 a consulting firm was engaged by the OC to provide a defects report. This has been forwarded to the Strata Manager. The SM has tried to contact the builder who has since become difficult to contact. In over a year nothing has happened and the problems are getting worse. There are a number of serious defects that need to be addressed. Should the OC put pressure on the Strata Manager, try and chase the builder independently, or commence a claim on insurance (via the SM?)?

Thanks.