Water Leaks From Above: Who Pays and How to Force a Repair

The owner briefing

• Water leaks move fast, so responsibility and evidence need to move faster.
• The first question is source: common property, lot property, or work done by an owner.
• Compensation depends on proof, mitigation, and a clear repair timeline.

Water leak disputes move quickly because damage spreads while everyone argues about responsibility. Source, evidence and timing matter from the first day.

Water leaks are one of the most common reasons apartment owners end up in strata, owners corporation or body corporate disputes around Australia. The tribunal name changes (NCAT in NSW, VCAT in Victoria, QCAT or the Commissioner's Office in Queensland, SAT in WA, SACAT in SA, ACAT in the ACT, and local pathways in Tasmania and the NT) but the argument is familiar everywhere: where did the water start, who controls that part of the building, and how quickly did the responsible body act?

The hard part is separating the source of the water from the place where the damage appears. Once that is clear, the legal pathway becomes much easier to follow.

The starting point: common property vs lot

Every strata leak dispute begins with the same question: is the source of the leak on common property, or within a lot?

The answer determines who is responsible for the repair, who pays, and what your rights are when the responsible party fails to act. It also turns on details that most owners, and many committee members, have never had reason to investigate.

In NSW, the common property memorandum and the registered strata plan together define what is common property. As a general rule, the structural fabric of the building is common property. This includes external walls, roofs, slabs between floors, balconies, façades, common plumbing and drainage stacks, common waterproofing membranes (including those under tiles in bathrooms and balconies), and any pipe that services more than one lot. Tiles, internal fittings, branch pipes that service only one lot, and surface finishes are typically lot property.

In Queensland, the picture depends on the format plan. Standard format plans (typical of villas and townhouses) generally place more responsibility on the lot owner. Building format plans (typical of high-rise apartments) place the structural fabric, including railings, parapets and external boundaries, with the body corporate.

In Victoria, the Owners Corporations Act 2006 and the registered subdivision plan together perform the same function as the NSW memorandum.

The waterproofing membrane is the critical category. Most strata leaks involve a failed membrane in a bathroom, balcony, kitchen or laundry. In NSW and Victoria, that membrane is almost always common property (even though it sits beneath tiles that are lot property) and the owners corporation is responsible for repairing it.

1. 01
   Leak appears in the lot
2. 02
   Source identified by plumber
3. 03
   Membrane, stack or shared pipe?
4. 04
   Common property: OC repairs
5. 05
   Internal fitting: upstairs lot owner
6. 06
   Strata insurance covers sudden escape

The doctrine of strict liability

In NSW, section 106 of the Strata Schemes Management Act 2015 imposes a duty on the owners corporation to maintain common property. Other states use different wording, but Victoria, Queensland, WA, SA, Tasmania, the ACT and NT all impose duties on the relevant owners corporation, body corporate, strata company or corporation to maintain common property or shared building elements.

The duty is strict. This is the key word, and it is the one that most committees do not understand.

Strict liability means the owners corporation is liable for the consequences of common property defects regardless of fault, regardless of intention, and regardless of how reasonable the OC's conduct has been. The OC cannot defend a claim on the basis that it did not know about the defect, that it has insufficient funds in the administrative or capital works fund, that the leak was not reasonably foreseeable, or that the committee was unable to organise repairs in time. The leak occurred. The common property is the source. The OC is liable.

The few defences available are narrow. Under section 106(3), the OC can pass a special resolution at a general meeting determining that it is "inappropriate" to repair a particular item of common property, but only if the decision will not affect the safety of the building or detract from its appearance. Under section 108, the OC can make a common property rights by-law that transfers responsibility for a specific item to one or more owners, but the affected owners must consent.

Outside these narrow paths, the OC's duty to repair is non-negotiable. The Appeal Panel of NCAT confirmed as recently as March 2026 (in a case concerning bathroom waterproofing) that an OC bears a strict obligation to repair common property regardless of a lot owner's views on scope or method. Adrian Mueller of JS Mueller & Co put it bluntly: "that's the law, like it or not; sometimes you just have to suck it up."

What if the leak is coming from the apartment above?

This is where most disputes get complicated. The water is in your unit. The source is in the unit above. Who is responsible?

The legal answer depends on where, exactly, the leak originates. If the source is a failed waterproofing membrane in the bathroom of the upstairs unit (which is common property) the OC is responsible. If the source is a burst flexible hose, a leaking tap, an overflowing washing machine, or an internal pipe that services only the upstairs lot, the upstairs owner is responsible.

This distinction is not academic. It determines whether you claim against your OC, against your neighbour, or against both.

A claim against the upstairs owner can be brought under several headings. Section 153 of the SSMA prohibits an owner from using their lot in a way that causes a nuisance or hazard to another occupier, and water damage caused by a failure to maintain internal fittings is generally a nuisance. The common law tort of nuisance also applies. And if the upstairs owner has carried out renovations under a by-law that allocates responsibility for the renovated area to that owner, the by-law itself transfers liability.

In practice, the building's strata insurance policy is often the first port of call. Most strata policies cover damage to lots arising from sudden and accidental water escape, even if the source is in another lot. Whether the policy responds, and whether the OC or the upstairs owner ultimately bears the cost, depends on the policy wording and the cause of the leak.

What you can recover

If your apartment has been damaged by a leak from common property, the OC's strict liability can extend beyond repairing the source to compensating you for losses caused by the failure.

The recoverable losses are substantial. They include the cost of repairs to lot property: replacing carpets, repainting, replacing damaged ceilings or walls, replacing damaged personal effects. They include rental loss for investor owners whose apartments have been rendered uninhabitable. For owner-occupiers, they include the cost of alternative accommodation while the unit is being repaired. They include expert fees, such as the cost of obtaining engineering reports, leak detection reports and mould assessments. And in NCAT proceedings, they can include legal costs.

The claim can be brought even where the OC eventually carries out the repair, if there has been an unreasonable delay. The compensation can cover the loss caused by the delay as well as the cost of the repair itself.

Your obligation as the affected owner is to mitigate your loss. The March 2026 Appeal Panel decision referenced earlier turned partly on the lot owner's conduct: she had refused to allow the OC's preferred repair method, removed bathroom tiles without coordination, and incorrectly assumed strata insurance would cover replacement tiling. Her rental loss claim was reduced because her own conduct contributed to the delay. The principle is that you must act reasonably to limit the damage, even while pursuing the OC's liability.

What to do when the OC won't act

The process for compelling repair, in roughly the order it should be followed, is well established.

The first step is a written notice to the strata manager and committee, identifying the leak, attaching evidence (photographs, video, plumbing reports), and requesting that the OC carry out repairs under section 106. The notice should specify a reasonable timeframe (typically 14 to 28 days for an initial response) and should be sent by email with a delivery confirmation.

The second step, if no adequate response is received, is to escalate within the OC. Many leaks become entrenched not because the OC is hostile but because a single committee member has decided the leak is not their problem, or because the strata manager has not pushed the issue. Writing directly to the chairperson or requesting that the matter be added to the agenda of the next general meeting can break the deadlock.

The third step is the local mediation or dispute-resolution process. In NSW that often means NSW Fair Trading before NCAT. In Victoria it may move through owners corporation dispute steps and VCAT. In Queensland, the Commissioner's Office is usually central. Other jurisdictions have their own tribunal or court pathways.

The fourth step is a tribunal or court application in the right jurisdiction. The order you want is usually practical: inspect the source, carry out specified works, pay compensation where available, and meet a timetable.

The fifth step, where available, is a regulator complaint. NSW now has stronger Fair Trading enforcement powers. Other states rely on their own consumer, land, body corporate or tribunal systems, so check the enforcement body before threatening action.

The state-by-state picture

The framework varies between jurisdictions, but the principle of OC responsibility for common property repairs is consistent.

Jurisdiction	OC Repair Duty	Tribunal	Compensation Available?
NSW	s 106 SSMA: strict liability	NCAT	Yes: repairs, rental loss, alternative accommodation, expert fees
VIC	s 46 OC Act: duty to repair common property	VCAT	Yes: repairs and consequential loss
QLD	BCCM Act: duty to repair common property; format plan determines scope	BCCM Commissioner / QCAT	Yes, subject to scheme module
WA	Strata Titles Act 1985: duty to maintain	SAT	Yes
SA	Strata Titles Act 1988 / Community Titles Act 1996: duty to maintain	Magistrates Court (not SACAT)	Yes
ACT	Unit Titles (Management) Act 2011	ACAT	Yes
NT	Unit Title Schemes Act 2009	NTCAT	Yes
TAS	Strata Titles Act 1998	TASCAT	Yes

What committees should be doing

The pattern of escalation that drives most leak disputes (owner reports the leak, OC delays, owner escalates, OC engages external help only when forced) is preventable. Committees that treat leaks as a serious priority avoid the rental loss claims, the legal fees, and the reputational damage that comes from being publicly identified as having failed to act.

The starting point is treating any reported leak as a potential breach of section 106 (or its state equivalent). The OC should commission a leak detection report within days, not months, of a complaint. It should engage a qualified plumber, builder or waterproofing specialist to identify the source, and should communicate the findings to the affected owner promptly.

The second step is acting on the report. If the source is common property, the OC should approve and carry out the repairs without waiting for legal pressure. If the source is in a lot, the OC should communicate this clearly to the affected owner along with the evidence.

The third step is documentation. Every leak, every report, every communication, every repair decision should be documented and stored. In the event of a subsequent NCAT application, the OC's documentary record is what determines whether the Tribunal accepts that the OC acted reasonably or finds that it failed in its duty.

Insurance decline is not a finding that nobody has to fix it

A water stain is three different questions. Mix them up and the emails last a year.

Whose thing failed? In NSW the starting map is the registered plan plus section 106 of the Strata Schemes Management Act 2015. A common-property pipe, roof or membrane is the owners corporation’s repair duty. A dishwasher hose inside the lot above is usually that owner’s problem — subject to any strict-liability overlay the cases in your state still apply. Victoria’s equivalent repair hook is section 46 of the Owners Corporations Act 2006. Queensland uses the Body Corporate and Community Management Act 1997 and the lot boundaries on the format plan.

Whose policy pays? The scheme’s damage policy under section 160 may respond to sudden building damage. It often will not respond to slow failure, wear, or a $7,500 excess on a $4,000 ceiling. An insurer’s “decline” is an insurance outcome. It is not a tribunal finding that section 106 has gone away. The owners corporation can still have to open the wall.

Who waits? The occupier downstairs. Every week of “we are waiting on the broker” is rental loss, mould and a nastier order. Commission a leak-detection report first. Tell both insurers second. Argue the excess third.

A five-day paper trail that usually wins

Day 1: written notice to the owners corporation and the upstairs occupier; photos; water isolated if safe. Day 2–3: licensed plumber or leak detector on site; common-property versus lot written in one paragraph. Day 4: committee or delegated officer authorises opening-up if the source is likely common. Day 5: both owners get the report. Keep that sequence. NCAT and VCAT read timelines more carefully than adjectives.

If the scheme is in South Australia, file in the Magistrates Court under the right Act. SACAT is the wrong heading on a leak letter. If it is Tasmania, the forum is TASCAT under the Strata Titles Act 1998, not the old planning appeal name.

Do not let a committee WhatsApp decide the source. The membrane does not care who is treasurer this year.

How UnitBuddy fits

UnitBuddy's defect tracking module logs every reported leak with photographs, plumbing reports, communications and repair decisions, and surfaces the OC's response time as a governance metric. The system automatically flags leaks that have been open for longer than the OC's policy threshold, and produces the documentary record that is required for both insurance claims and tribunal proceedings.

For owners, the platform provides clear visibility over which leaks have been reported, who is responsible, and what the OC is doing about them, closing the information gap that drives so many disputes from minor irritation into formal proceedings.

Related reading

• Common lot vs common property explained
• How to force a strata scheme to fix a defect
• Mould in your apartment: your legal rights

Sources and further reading

• NSW Government: changes to strata laws
• NSW Government: guide to strata law changes for committees and owners
• NSW: Water leaks, defects and disputes in strata buildings, via LookUpStrata
• WA: Who pays for water damage from the unit above?, via LookUpStrata

Keep the scheme file in one place the committee and the manager can both open. Features, pricing, or book a tour.