Can I be sued for vaad bayit arrears if I live abroad?

Yes. The vaad bayit can file a claim in the Israeli Magistrates Court regardless of where you are physically located. If you were not registered at an Israeli address with the committee, notice sent to the apartment address is legally sufficient. A judgment can be entered in your absence and enforced through the Execution Office, which can register a lien on the apartment title at the Land Registry — blocking any future sale until the debt is cleared.