Who is responsible for that water leak?

In Queensland, responsibility for water leaks in apartments depends on the location of the leak within the strata scheme. The Body Corporate (also known as the Owners Corporation) is generally responsible for leaks originating from common property areas, like shared walls, roofs, and pipes within common areas. If the leak originates from within a specific lot (an individual apartment), the lot owner is usually responsible for repairs.

A specific example

In a group of 9 units water leaked from a unit 6 into both unit 2 and 3. This is complex because the leak manifested near the bathroom door in unit 2. So the obvious source of the leak was from the toilet or from the tile floor or even the water heater.

Multiple plumbers and bathroom specialists were unable to diagnose the cause of the leak in unit 2. The toilet walls were investigated. The hot water system was replaced.
Eventually the cause of the leak was only discovered when the unit complex agreed to fix the leak of unit 6 at the body corporate expense.

Co-operation of unit owners is necessary in a scenario where cause is difficult to estatblish.

Common Property Responsibility

The Body Corporate is responsible for maintaining the structural integrity of the building, including roofs, foundations, and external walls.

They are also responsible for maintaining and repairing shared utilities, such as water pipes and electrical wiring, in common areas.
If a leak originates from a main pipe in the building's underground parking, it is generally the Body Corporate's responsibility.
Water damage caused by a failed building membrane is usually the Body Corporate's responsibility.
The Body Corporate is typically responsible for insuring common property and fixtures and fittings within a lot, with some exceptions.

Lot Owner Responsibility

If a leak originates from within a specific lot, such as a faulty tap or plumbing within the unit, the lot owner is generally responsible for repairs. If a lot owner fails to maintain their unit, and this causes damage to another lot, the responsible lot owner may be liable for the damage.

Disputes and Insurance

Disputes can arise when it's unclear whether a leak originates from common property or an individual lot as in the case above. In such cases, the Body Corporate may need to investigate and potentially involve insurers.

Strata insurance typically covers accidental damage from burst pipes or leaking faucets, but not necessarily gradual wear and tear or poor maintenance.

It's crucial for the Body Corporate to have adequate insurance coverage for common property, especially if the building has a standard format plan with shared walls.