If you own a freestanding house, you are generally responsible for arranging building insurance if you want cover for the building.
If you own a strata property, the building is usually insured by the strata body corporate. Building cover is generally not available for strata lots where the building is required to be insured by a strata body corporate or similar entity.
Some property types, such as certain Survey Strata schemes in WA or Standard Format Plan properties in QLD, may be treated differently because the body corporate may not be required to insure the building.