When your apartment suffers water damage, the last thing to ask is who should claim on their insurance. The first thing is who’s responsible, then ask what, where and why. 

Who - In strata, there can only be one of two parties ultimately responsible for fixing something that’s broken and paying for the damages that the breakage has caused - lot owners or the strata (i.e., the body corporate or owners corporation)? 

What - Lot owners are responsible for lot property, and strata is responsible for common property. The difference between these two types of property in a strata are different in each state and territory. For NSW there is a help guide published by Bannerman’s Lawyers.

Where - Pipes and ducts can be lot property in some places and common property elsewhere, so sometimes it comes down to where the damage is situated.  

Why - If damage is caused by someone’s else’s property or their negligence, it’s on them, despite the location of the damage. After you take responsibility for fixing your property, you can recover the damages for the party in the wrong. 

Having first worked out the who, what, where, and why of the situation then, and only then can you turn to the question of insurance who’s has insurance is the last thing to consider. Then it’s up to the insured to claim but the outcome of the insurance claim is a matter between the insurer and the insured, it doesn’t change the primary responsibility for fixing the property and covering the loss.