Depende sa insurance company yan. Most allow it, some dont. It also depends on the casa's experience with the insurer. Minsan kasi pag may bad experience na sila regarding payment, automatically blacklisted na yung insurance company. Likewise if an insurance company has discovered some anomalies in the casa, then blacklisted naman yung casa sa kanila. What you can do is to try to submit a quotation from your preferred casa to the insurance. Let them negotiate with your casa and if all goes well, they might allow you to have your unit repaired there.