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

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

Water leaks are the single most common reason an apartment owner ends up at NCAT. Cases related to water leaks, delays in fixing them, and claims for compensation for rental loss have driven a 45% increase in strata applications to the Tribunal over the past five years. There are now more than 85,000 strata schemes in NSW alone, and the legal framework that governs who fixes a leak — and who pays — is one of the most consistently misunderstood areas of strata law.

This article breaks down the legal position across NSW, Victoria and Queensland, explains the doctrine of strict liability that controls owners corporation responsibility, walks through what to do when the OC refuses to act, and addresses the question that drives so many of these disputes: when the leak is coming from the apartment upstairs, who is actually liable for the damage to your unit?

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.

The Doctrine of Strict Liability

Section 106 of the Strata Schemes Management Act 2015 (NSW) imposes a duty on the owners corporation to properly maintain and keep the common property in a state of good and serviceable repair, and to renew or replace any fixtures or fittings comprised in the common property.

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 extends not just to repairing the source, but 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 — the cost of obtaining engineering reports, leak detection reports, 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 is for the loss caused by the delay, not just 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 mediation through NSW Fair Trading. Mediation is free, takes around six to eight weeks to schedule, and is required before NCAT will hear most strata disputes. Many cases resolve at this stage because the OC's solicitor explains, in plain terms, that section 106 is strict and the OC will lose at NCAT.

The fourth step is an application to NCAT. The Tribunal has the power to order the OC to carry out specified works within a specified timeframe, to pay compensation, and in extreme cases to appoint an administrator to manage the OC and organise the repairs. Applications attract a modest filing fee and can be self-represented. Decisions are typically issued within four to six months of filing.

The fifth step — rarely needed but available — is a complaint to NSW Fair Trading under the new October 2025 enforcement powers. Fair Trading can investigate, require documents, issue compliance notices, and seek enforceable undertakings against owners corporations that breach their section 106 duty. The mechanism is intended for cases where NCAT orders are being ignored or where the OC's conduct is part of a broader pattern of failure.

The State-by-State Picture

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

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.

How UnitBuddy Helps

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.

Water leaks are the most common, most expensive, and most preventable category of strata dispute in Australia. The framework gives owners strong rights and committees clear obligations. The buildings that get this right are the ones that treat the duty to repair not as a defence to litigate but as a baseline of good governance.