Who fixes what: common property, lots and water leaks in New South Wales

In short

• The registered plan draws the line. Everything inside a lot's boundaries belongs to the owner, and everything else is common property. Where the plan is silent, each state has a default rule. In NSW, WA, SA and for older NT schemes the default boundary is the inner surface of the walls, the upper surface of the floor and the under surface of the ceiling. In TAS and the ACT it is the centre of the wall, floor or ceiling. In VIC the plan itself must say which kind of boundary applies. In QLD it depends on whether the scheme is on a building format plan or a standard format plan.
• The scheme maintains and repairs common property. Every state and territory gives the owners corporation, body corporate, strata company or corporation that job. NSW, VIC, QLD, WA, the ACT and the NT's older 1975 Act put it as a duty; SA and TAS list it among the corporation's functions; the NT's 2009 Act speaks only of managing the common property. Some states go further. In QLD, building format plan schemes must also maintain roofs, foundations, load-bearing walls and boundary windows and doors. In the ACT, schemes must also maintain the load-bearing parts and balconies of apartment buildings, even where they sit inside a lot.
• Owners look after their own lot. That duty comes from the Act, the regulations or the by-laws, depending on the state. Things that serve only one lot, such as its hot water system, air conditioner and the pipes and wiring inside the lot, are usually the owner's. A by-law can change that, and the exact rule differs by state.
• For a leak, the source decides. If the water comes from common property, such as a roof, a shared pipe, a slab membrane or a boundary window, the scheme usually fixes the source. If it comes from something that belongs to a lot, such as a tap, a shower or an owner-laid tile, that owner usually does. The damage it causes is often a claim on the scheme's building insurance, and who pays the excess varies by state and by policy.
• The scheme can enter a lot to do its work, usually after written notice (7 days in VIC, QLD, WA and the ACT) and at any time in an emergency. In most states it can also do work an owner fails to do and recover the cost.
• An owner can make the scheme repair through the state's dispute process: NCAT in NSW, VCAT in VIC, the Commissioner's adjudicators in QLD, SAT in WA, the Magistrates Court in SA, the Recorder of Titles in TAS, ACAT in the ACT and NTCAT in the NT. In NSW the Act also lets an owner claim damages for loss caused by a failure to repair, within 6 years.

How it works

Step 1: find the boundary

A strata or unit plan shows each lot and the common property around it. Common property is simply whatever is not inside a lot. In a building, the question is where exactly the lot stops. The answer decides who owns, and usually who maintains, the walls, floors, ceilings, windows, doors and balconies.

Each Act sets a default rule that applies unless the plan says otherwise:

State	Default boundary in a building	Where it comes from
NSW	Inner surface of walls, upper surface of floor, under surface of ceiling	Strata Schemes Development Act 2015 s 6
VIC	No single default: the plan must say "interior face", "median" (middle of the structure), "exterior face" or another location	Subdivision (Registrar's Requirements) Regulations 2021 reg 10
QLD	Building format plan: the building's floors, walls and ceilings (the Commissioner describes this as the centre). Standard format plan: land boundaries marked on the ground	Land Title Act 1994 ss 48A to 48D
WA	Strata scheme: inner surface of walls, upper surface of floor, under surface of ceiling. Survey-strata scheme: land boundaries, with no building on the plan	Strata Titles Act 1985 ss 3(2) and 9
SA	Strata: inner surface of walls, upper surface of floor, under surface of ceiling	Strata Titles Act 1988 s 5(5); Community Titles Act 1996 s 19(4)
TAS	Centre of the boundary structure (wall, floor, ceiling or fence)	Strata Titles Act 1998 s 5(3)
ACT	Centre of the floor, wall or ceiling, including external walls	Unit Titles Act 2001 ss 14 and 15
NT	Schemes under the 2009 Act: the dividing structure is not part of the unit unless the scheme statement says otherwise. Older schemes under the 1975 Act: inner surface of walls, upper surface of floor, under surface of ceiling	Unit Title Schemes Act 2009 s 37; Unit Titles Act 1975 s 4

The plan always wins over the default. Older plans can follow different rules, and a later by-law or plan amendment can move things around, so the first step in any repair question is to get a copy of the registered plan and the current by-laws. The plan is available from the state's land titles office.

Step 2: who maintains each side

The general pattern is the same everywhere:

• Common property (roof, structure, external walls, shared pipes and wiring, lifts, driveways, gardens, shared facilities) is maintained and repaired by the scheme and paid for from levies. See budgets and levies.
• The lot (internal walls, fixtures, fittings, appliances, floor coverings, paint inside) is maintained by its owner.
• By-laws can move responsibility. A common property rights or exclusive use by-law usually makes the owner who gets the benefit, such as a courtyard or a parking space, responsible for maintaining that area. In some states a by-law or resolution can also take on work for owners. See by-laws.

Step 3: the grey areas

These cause most of the arguments. The table shows the usual position, but the plan, the by-laws and the state's rules decide each case.

Item	Usual position	Why it varies
Windows and window frames	Scheme, where they sit in a boundary or external wall	The boundary rule. In TAS and the ACT the boundary runs through the middle of the wall. In QLD building format plans the body corporate maintains boundary windows by law
Balcony balustrades and railings	Scheme	QLD building format plans and the ACT say so expressly. Elsewhere it follows the plan
Balcony tiles and waterproofing	Original tiles and membrane: often the scheme. Tiles an owner laid later: that owner	Whether the balcony is inside the lot. NSW's optional common property memorandum gives original tiles and waterproofing to the owners corporation
Front entry door to the lot	Often the scheme, as it sits in the boundary wall	NSW memorandum: the owners corporation maintains it, except extra locks and keys
Pipes and wiring serving one lot	Owner, if inside the lot. Scheme, if inside a boundary wall or slab, or if they serve more than one lot	QLD Act s 20: anything in a boundary structure is common property. VIC s 129: the owner maintains a service that serves only their lot
Hot water system serving one lot	Owner, even if it sits on common property	QLD Standard Module s 180(4), NSW memorandum, VIC s 129(b)
Air conditioner serving one lot	Owner, even if the outdoor unit is on the roof or common property	QLD Standard Module s 180(4), NSW memorandum
Bathroom waterproofing	Depends on whether the membrane is in a common property floor or wall, and who installed it	NSW memorandum: original membranes on common property floors and walls go to the owners corporation. QLD: the owner maintains the shower tray (Standard Module s 180(4)(b))
Internal walls, carpet, internal paint	Owner	Same everywhere

Step 4: water leaks between units

A leak usually involves three separate questions: stopping the water, fixing the cause and paying for the damage. In general terms, this is how schemes usually work through one.

1. Stop the water and make it safe. Turn off the lot's stopcock, or ask the committee or manager to isolate the supply. Most Acts let the scheme enter a lot without notice in an emergency, and VIC's Act names a leak as an emergency (Owners Corporations Act 2006 s 51(3)). See "The scheme's right to enter a lot" below.
2. Tell the scheme in writing straight away, with photos, the date and the units affected. Insurers and tribunals look closely at when the scheme was told.
3. Find the source. In practice the committee or manager usually brings in a plumber or leak detection specialist, because the source decides everything else. Owners give access to their lots as each Act requires.
4. Fix the source. If the source is common property, such as a roof, a shared riser, a slab membrane or a boundary window seal, the scheme fixes it. If the source belongs to a lot, such as a tap, toilet, flexi hose, shower screen or tiles the owner laid, that owner fixes it. If the owner does not, the scheme can usually do the work and recover the cost (see "When an owner will not do the work" below).
5. Deal with the damage. Damage to the building, including other lots' ceilings and walls, is often covered by the scheme's building insurance, and the scheme makes the claim. Owners' and tenants' own contents insurance covers contents. The excess depends on the state's rules, the policy and any by-law. See insurance and the table below.
6. If someone was at fault, for example an owner who ignored a known leak, the scheme or the affected owner may be able to recover costs from them. The ACT and VIC Acts deal with this expressly. Elsewhere it is mostly the general law.
7. If it stalls, use the scheme's dispute steps and then the state's tribunal or commissioner. See disputes.

Who pays the insurance excess. Only some Acts say:

State	What the law says about the excess on the scheme's building policy
NSW	Nothing in the Act's insurance Part; it depends on the policy and any by-law (Strata Schemes Management Act 2015 Part 9)
VIC	The owners corporation may levy an owner for the excess on a claim relating solely to their lot, or caused by the culpable or wilful act or gross negligence of the owner, their tenant or a guest (Owners Corporations Act 2006 s 23A(3))
QLD	Event affecting only 1 lot: the owner pays unless the body corporate decides that is unreasonable. Event affecting 2 or more lots, or a lot and common property: the body corporate pays unless it decides otherwise (Standard Module s 203)
WA	Nothing in the Act or the general regulations
SA	Strata corporations: nothing in the Act. Community corporations: "any excess or shortfall resulting from under insurance" is met by the corporation (Community Titles Act 1996 s 103(3))
TAS	The body corporate pays, but for an event affecting only 1 lot the owner pays unless the body corporate decides by ordinary resolution that this would be unreasonable (Strata Titles Act 1998 s 99(4) and (5))
ACT	The owners corporation lodges the claim and pays the excess, and can recover a cost caused by an owner's or occupier's wilful or negligent act or rule breach (Unit Titles (Management) Act 2011 ss 100A and 31)
NT	Nothing in the Act or the management modules

State by state

New South Wales

Boundaries. Unless the plan describes the boundaries another way, a lot's vertical boundaries are the inner surface of the walls, and its horizontal boundaries are the upper surface of the floor and the under surface of the ceiling. "Wall" includes doors and windows (Strata Schemes Development Act 2015 ss 4 and 6). Pipes, wires, cables and ducts that are not for the exclusive benefit of one lot are common infrastructure, which is common property unless it forms part of a lot (s 4). Lots in older schemes under the Conveyancing (Strata Titles) Act 1961 had boundaries at the centre of floors, walls and ceilings; where the plan did not say otherwise, those boundaries are now taken to be the upper surface of the floor, the inner surface of the wall and the under surface of the ceiling (Sch 8 cl 10). Plans can still describe boundaries their own way, so check the plan itself.

The owners corporation's duty. The owners corporation must properly maintain the common property and keep it in good and serviceable repair. It must also renew or replace fixtures and fittings (Strata Schemes Management Act 2015 s 106(1) and (2)). There are three limits:

• It can decide by special resolution not to repair a particular item, but only if repair is inappropriate and the decision will not affect safety or the building's appearance (s 106(3)).
• It can hold off repairing damage while it pursues whoever caused it, as long as safety, access and use are not affected (s 106(4)).
• The duty is subject to any common property memorandum, common property rights by-law or s 108 by-law that moves the work to an owner (s 106(7)).

Owners' duties. The Act does not set a general "maintain your lot" duty. It does stop owners from interfering with support, shelter or services (s 151) and from causing a nuisance or hazard (s 153). They must also give 14 days' notice before altering the lot's structure (s 152). The model by-laws for residential schemes do not add a general duty to maintain the lot either, although an owner who installs things such as locks, screens or safety devices on common property must keep them in repair (Strata Schemes Management Regulation 2016 Schedule 3 by-law 2). A scheme's own by-laws may set out more.

The common property memorandum. NSW has an optional, government-made list of who maintains what. It applies only if the scheme adopts it by by-law (s 107; Strata Schemes Management Regulation 2016 cl 27). Under it:

• The owners corporation maintains windows in common property walls, original tiles and waterproofing, balcony railings and ceilings, pipes in common property walls, floors and ceilings, the main stopcock, and hot water and air conditioning systems serving more than one lot.
• The owner maintains pipes downstream of the stopcock that serve only that lot and are not in a common property wall. The owner also maintains taps, toilets, baths, shower screens, tiles and waterproofing they laid later, and any hot water system or air conditioner serving only their lot.

See the memorandum.

Entry. The owners corporation may enter any part of the scheme to do or assess its own work: at any time in an emergency, and otherwise with the occupier's consent or a Tribunal order (s 122). The Act sets no fixed notice period. NCAT can order an occupier to give access (s 124). The owners corporation is liable for damage it causes when it enters, unless it was obstructed (s 122(6)).

When an owner will not do the work. The owners corporation can do work an owner or occupier was required to do but did not, under a by-law, a public authority notice, an order under the Act, or to remedy a breach of their duties in Part 8 of the Act (such as interfering with support or services), and recover the cost as a debt (s 120).

Making the owners corporation repair, and damages. An owner who suffers loss because the owners corporation failed in its s 106 duty can recover reasonably foreseeable loss as damages (s 106(5)). The claim must be brought within 6 years after the owner first becomes aware of the loss (s 106(6); the limit was 2 years before 1 July 2025). NCAT can make orders to settle a dispute, including about a failure to act (s 232), and most applications need mediation through NSW Fair Trading first (s 227). NCAT can also order the owners corporation to consent to repairs an owner proposes to carry out on common property if it has refused unreasonably (s 126). Since 27 October 2025 NSW Fair Trading can also investigate the repair duty and issue compliance notices (Part 10A, ss 188A to 188ZC).

Leaks. NSW Fair Trading's guidance is that the owners corporation repairs common property and owners repair their own property. An owner who calls an emergency tradesperson may be able to get a refund from the owners corporation by showing the problem came from something it is responsible for, such as water damage from plumbing in a boundary wall (Strata repairs and maintenance).

If it goes wrong: where to get help

State	Contact first	Who decides disputes
NSW	NSW Fair Trading, 13 32 20 (free strata mediation)	NCAT
VIC	Consumer Affairs Victoria, after the owners corporation's own dispute process	VCAT
QLD	Office of the Commissioner for Body Corporate and Community Management	Commissioner's conciliation and adjudication; QCAT on appeal
WA	Landgate strata enquiries, (08) 9273 7047	State Administrative Tribunal
SA	SA strata titles information and community mediation	Magistrates Court
TAS	Land Titles Office, NRE Tasmania	Recorder of Titles
ACT	Access Canberra	ACAT
NT	NT Consumer Affairs	NTCAT

For building defects in a newer building, statutory home warranty and builder rectification schemes may also apply. Those are separate from the scheme's repair duty.

How FairLot helps

• Maintenance requests: owners log a leak or repair with photos, the committee or manager assigns it, and everyone can see its status. The record shows when the scheme was told, which matters if a repair is later disputed.
• Documents: keep the registered plan, by-laws, any common property memorandum or exclusive use by-laws, and contractor reports in one searchable place, so "whose is this?" starts from the right papers.
• Insurance register: the building policy, sum insured, excess and broker details, with renewal reminders.
• Owner portal and audit trail: owners see their requests and the scheme's documents, and every change is recorded with who made it and when.

FairLot is software only. It does not decide who is responsible, arrange repairs or insurance, or give legal advice.

Common questions

Water is coming through my ceiling from the unit above. Who pays?

It depends on where the water starts. If it comes from common property, such as a shared pipe in the slab, a failed membrane or the roof, the scheme usually fixes the source. If it comes from the unit above's own fittings, such as a shower, tap or flexi hose, that owner usually does. Damage to the building is often claimed on the scheme's building insurance. QLD (Standard Module s 203), VIC (Owners Corporations Act s 23A), TAS (Strata Titles Act s 99), the ACT (Unit Titles (Management) Act s 100A) and SA community corporations (Community Titles Act s 103(3)) have rules on who pays the excess; elsewhere it depends on the policy and by-laws. See the excess table above and insurance.

Can I just get my own plumber to fix a leaking common pipe?

Be careful. In VIC an owner must not repair common property or a shared service unless the owners corporation has expressly authorised it (s 47A). In other states an owner who arranges common property work without approval may not be reimbursed. NSW Fair Trading notes an owner who calls an emergency tradesperson may be eligible for a refund if they can show the problem came from something the owners corporation is responsible for, such as plumbing in a boundary wall. Telling the scheme in writing first, or at the same time in an emergency, keeps the options open.

Are my windows and balcony mine or the scheme's?

Usually the scheme's where the window sits in an external or boundary wall: the plan decides. QLD building format plans make the body corporate maintain boundary windows, doors and balustrades (Standard Module s 180(2)). The ACT makes the owners corporation maintain any part of a balcony (s 24). In NSW, schemes that adopt the common property memorandum give balcony railings, ceilings and original tiles and waterproofing to the owners corporation. Tiles an owner laid later are generally the owner's.

My hot water system and air conditioner are on the roof. Who looks after them?

In most states, the owner of the lot they serve. QLD says so expressly even where they sit on common property (Standard Module s 180(4)), VIC requires owners to maintain services that serve only their lot (s 129), and the NSW memorandum takes the same view. A by-law can change this.

Can the committee come into my unit?

Yes, for the scheme's own work. In VIC, QLD, WA and the ACT the scheme gives at least 7 days' written notice. In NSW the scheme needs the occupier's consent or a Tribunal order. In SA it gives at least 2 days' notice for work an owner failed to do. In TAS the model by-laws require reasonable notice. In an emergency, such as an active leak, entry without notice is allowed almost everywhere. See each state's section above.

The scheme will not fix a leak that is damaging my unit. What can I do?

Put the request in writing, with photos. Then use the scheme's dispute steps and the state's tribunal or commissioner: NCAT, VCAT, the QLD Commissioner, SAT, the SA Magistrates Court, the TAS Recorder of Titles, ACAT or NTCAT. In NSW an owner can also claim damages for loss caused by a failure to repair common property, within 6 years of becoming aware of the loss (s 106(5) and (6)). In QLD an adjudicator can order repairs or reimbursement (s 281). See disputes.

The owner upstairs will not fix their leaking shower. What can the scheme do?

In most states the scheme can require the work and, if it is not done, do it and recover the cost. That covers NSW s 120, VIC s 48 (28 days' notice), QLD s 161, WA s 94 and SA s 28 (community corporations s 101). In the ACT the scheme can recover costs caused by an owner's negligence or a rule breach (s 31). In TAS the route is a by-law compliance notice and then TASCAT or the Recorder of Titles (ss 95 and 96). Entry rules still apply.

Does a townhouse scheme work differently?

Often, yes. In QLD standard format plans and WA survey-strata schemes, lots are areas of land, so the owner usually maintains their whole building, including the roof and external walls, and the scheme looks after shared land and services. SA community lots and ACT class B units work in a similar way. Check the plan type first.

Who decides whether something is common property?

The registered plan, read with the Act's default boundary rule and the scheme's by-laws. If owners still disagree, the state's tribunal or commissioner decides. Questions about renovating or altering common property are covered in renovations. The committee's general duties are in self-managing committee duties.

Sources

• Strata Schemes Management Act 2015 (NSW) : ss 106 to 108, 120, 122, 124, 126, 151 to 153, 160 to 171, 188A to 188ZC, 227, 232 (version current for 26 August 2026; point-in-time versions of 2 March 2025, 1 July 2025 and 27 October 2025 for the 2025 changes; read 2 October 2026).
• Strata Schemes Development Act 2015 (NSW) : ss 4 and 6, lot boundaries; Sch 8 cl 10 (version current for 10 June 2026).
• Strata Schemes Management Regulation 2016 (NSW) : cl 27, common property memorandum; Schedule 3 model by-laws.
• NSW common property memorandum : item by item responsibilities.
• NSW Fair Trading: strata repairs and maintenance : who repairs what, emergency repairs and refunds.
• NSW guide to strata law changes : 2025 repair reforms.
• Owners Corporations Act 2006 (Vic) : ss 23A, 46 to 51, 129 to 132, Parts 10 and 11 (authorised version 024, as at 9 September 2026).
• Subdivision (Registrar's Requirements) Regulations 2021 (Vic) : reg 10, boundary types.
• Consumer Affairs Victoria: maintaining individual lots and common property : regulator guidance.
• Body Corporate and Community Management Act 1997 (Qld) : ss 20, 161, 163, 281, 289, 290.
• Body Corporate and Community Management (Standard Module) Regulation 2020 (Qld) : ss 180, 203, 211, 212.
• Land Title Act 1994 (Qld) : ss 48A to 48D, plan formats.
• QLD Commissioner: building format plan maintenance and utility infrastructure : regulator guidance.
• Strata Titles Act 1985 (WA) : ss 3, 9, 65, 66, 91, 94, 95, 197, Schedule 1 by-law 1 (consolidation 08-a0-00, current from 26 June 2025).
• Landgate: WA Strata Living Guide (November 2023) : common property, exclusive use, dispute steps.
• Strata Titles Act 1988 (SA) : ss 5, 25, 27, 28, 41A, 42, Sch 2 cl 2, Sch 3 (version in force from 9 December 2021, confirmed current 2 October 2026).
• Community Titles Act 1996 (SA) : ss 19, 75, 101, 103, 134, 142 (version in force from 9 December 2021, confirmed current 2 October 2026).
• Legal Services Commission SA: Strata Titles, a legal guide (December 2021) : pre-1988 boundaries, leaking pipe example.
• Strata Titles Act 1998 (Tas) : ss 3A, 5, 9, 81, 90, 94 to 96, 99, 105, 114, 116, Schedule 1.
• Unit Titles Act 2001 (ACT) : ss 14 and 15, boundaries.
• Unit Titles (Management) Act 2011 (ACT) : ss 24 and 26 to 31, 100A, 125, 129 (republication 25, 26 June 2026).
• Unit Titles (Management) Regulation 2011 (ACT) : Schedule 1 default rule 1.3.
• Unit Title Schemes Act 2009 (NT) : ss 27, 33, 37, 50, 51, 84 to 86, Schedule 2 by-laws (as in force at 27 November 2023, still current).
• Unit Title Schemes (Management Modules) Regulations 2009 (NT) : Modules 1 and 2 cl 49 (as in force at 12 May 2023, still current).
• Unit Titles Act 1975 (NT) : ss 4, 34, 45, 106, Schedule 1 art 2 (as in force at 27 November 2023, still current).