If, or when, something goes wrong either in your unit itself, or to the services or utility infrastructure connected to your unit, the first question asked is often 'who has to fix this?'

A water leak, a cracked balcony tile, an apparently deteriorating window frame or perhaps a failed pipe can all give rise to the same question. In strata complexes within the ACT, the answer is not always straightforward. Responsibility for repair usually turns on the questions of:

• what specific building element has failed, being precise as to the nature and location of the failure;
• does that specific element form part of the unit property, is it common property, or is it perhaps part of a 'defined part' of the unit;
• is the unit a Class A or Class B unit; and
• for units in a scheme which are entirely Class B, has the owners corporation validly passed a special resolution taking on certain additional maintenance obligations, or excluding itself from certain insurance obligations.

To give yourself the best start in determining who may be responsible for a repair, consider the four steps below. At the end of this article is a checklist, designed to assist you in understanding where responsibility may fall. Remember that if a 'defective' building element, in the legal sense of the element not having been built as is required by law, is the cause of loss or failure, your owners corporation's building insurance likely will not respond to protect you from the defective building work itself, though it may cover you for consequential damage.

Step 1: Start with the legal boundary

The first step is to understand where the unit legally ends and where the common property begins.

Understanding the legal boundary will assist you with determining whether, in relation to the building element which has failed, that element is:

• something you own and must repair or maintain;
• something you own which the owners corporation must maintain; or
• something the owners corporation owns and must maintain, and therefore something you have no right to fix, even if you want to.

In the ACT, the registered units plan is the document which provides the most assistance in determining which of the above categories the failed building element belongs to. The Unit Titles Act 2001 (ACT) (UTA) provides the legal framework under which units plans may be registered, and it sets the legal boundaries of each unit and the common property. In strata schemes comprised solely of Class A units in the ACT, those boundaries typically run through the mid-point of walls, floors and ceilings. While that is the starting point, it is not always the case. For that reason, the registered units plan should be checked when determining who is responsible for the repair.

Your registered units plan will contain a cover page, a schedule of entitlements, drawings of each level or floor of the building including any basements, and will have some attached forms (Form 4 and Form 5). Find your unit and any subsidiaries within the registered units plan. Once the boundary of your unit is clear to you from the plan, the next step is to consider who is obliged to repair the building element that has failed.

Section 24 of the Unit Titles (Management) Act 2011 (ACT) (UTMA) is the source of a statutory duty on the owners corporation, making it responsible for maintaining common property. In Class A schemes, an owners corporation is also required to maintain certain other defined parts of a building, whether or not those parts are common property, being balconies and certain load bearing structures. But that does not mean that issues related to any external element of your building automatically fall to the owners corporation. Responsibility still depends on the registered units plan, the statutory framework of the UTMA and the facts of the particular issue.

Step 2: Common property and defined parts

Common property

Under the UTA, common property is the part of the parcel identified as common property on the units plan. This is the definition provided by section 13 of the Unit Titles Act 2001 (ACT). The section refers to those parts of the block which are marked as common property on the registered units plan, which is why the plan is so important. That is why shared driveways, foyers, lifts, stairwells, gardens, shared roofs, external walls and service infrastructure are often common property. However, whether they are common property in your particular scheme depends on the markings on your registered units plan.

If something is marked common property and the units in your units plan are all Class A units, then the owners corporation will generally be responsible for maintaining that item of common property, because of the obligations imposed on it by section 24 of the UTMA. If there are both Class A and Class B units mentioned in your registered units plan, you should seek specialised advice about the statutory duties of your owners corporation.

Defined parts

'Defined parts' of a building form a separate statutory category from common property. Section 24(4) of the UTMA defines the defined parts of a building containing Class A units as:

• load-bearing walls;
• load-bearing columns;
• load-bearing footings;
• load-bearing slabs;
• load-bearing beams; and
• any part of a balcony on the building.

This matters because, in a Class A scheme, subsection 24(1)(d) of the UTMA requires the owners corporation to maintain those defined parts whether or not they form part of the common property.

In other words, a building element may sit outside the common property boundaries shown on the units plan, but the owners corporation may still be responsible for maintaining it if it falls within the statutory definition of a defined part.

Why the distinction matters

For owners, the practical position is usually this:

• common property is generally maintained by the owners corporation;
• in a Class A scheme, the owners corporation must also maintain the statutory defined parts of the building, even if they are not common property; and
• if an item is neither common property nor a defined part that the owners corporation must maintain, responsibility is more likely to sit with the unit owner, subject to any special resolution passed in a Class B scheme under subsection 24(1)(g) of the UTMA.

So the real question is not just, 'is it inside my unit?'

It is also:

• what exactly has failed?
• where is the legal boundary on the registered units plan?
• is the item that has failed part of the common property?
• if the unit is in a Class A scheme, is it one of the statutory defined parts?

Step 3: Is the scheme Class A or Class B?

Class A schemes

Class A schemes are generally apartment-style developments. In these schemes, the owners corporation's obligations can extend beyond common property to certain defined parts of the building. Depending on the issue, that may include some structural elements and some balcony-related elements. But responsibility for windows, waterproofing and other parts of the external building envelope is not determined by appearance alone. It depends on the registered units plan, the statutory framework and the legal character of the item in question.

A common issue is responsibility for sliding doors and balcony walls. In the ACT, the answer depends less on labels like 'external wall' and more on what the units plan shows. If the door or wall opens onto a balcony, courtyard or terrace that forms part of the unit, it will usually be the owner's responsibility, not the owners corporation's: McMillan v Owners Corporation – Units Plan No 79 [2019] ACAT 86; Owners of Units Plan 3323 v Makeham [2024] ACAT 46.

By contrast, if it borders common property, or involves a load-bearing wall or part of a balcony in a Class A building, the owners corporation may still be responsible under section 24 of the UTMA. The key point is that you cannot assume who is responsible. You need to check the registered units plan.

In McMillan v Owners Corporation Units Plan No 79 [2019] ACAT 84, the Tribunal made clear that a window or door is not necessarily the owners corporation's responsibility just because it appears to form part of the outside of the building. The real question is how the element is characterised under the units plan and the legislation. In that case, the balcony window-doors were held not to be part of the balcony or common property, but instead to sit between the unit and a unit subsidiary. As a result, maintenance remained the owner's responsibility.

The decision is a useful reminder that, in Class A schemes, responsibility for windows, doors and similar building elements depends on legal characterisation, not appearances.

Service and utility conduits can also be more complicated than owners expect. Under the UTMA, the owners corporation is generally responsible for maintaining utility conduits only where the relevant utility service is provided for the potential benefit of all units. If, however, a particular part of a conduit, pipe, cable, duct or similar infrastructure serves only one unit, it is likely to be the responsibility of that unit owner to maintain. ACT tribunal decisions show that the dividing line is not simply where the infrastructure is located, but whether that part of the system forms part of a service available to all units or is instead associated only with the supply of services to a particular unit.

Class B schemes

Class B schemes are usually townhouse-style developments. In these schemes, the unit owner is generally responsible for maintaining the unit, including items that an owner in a Class A building might expect the owners corporation to deal with.

An owners corporation does not automatically have to maintain buildings on Class B units. Instead, under section 24(1)(g) of the UTMA, it only takes on those obligations if authorised by special resolution. That allows it to assume some categories of work, such as external painting, roofing or structural repairs, while excluding others, such as internal painting or minor repairs. If the units plan contains only Class B units, the owners corporation may also exempt itself from certain building insurance requirements by unanimous resolution, although public liability insurance must still be maintained.

However, that is not always the end of the matter. A Class B owners corporation can take on additional maintenance obligations by passing a special resolution.

In Brudenall & Anor v The Owners – Units Plan No 202 (Appeal) [2019] ACAT 87, the Appeal Tribunal considered a Class B scheme in which the owners corporation had previously passed a special resolution taking responsibility for painting, roofing and structural repairs to the Class B units. A dispute later arose when the owners corporation replaced deteriorated concrete tile roofs on the Class B townhouses with Colorbond roofing, and it was argued that complete replacement went beyond what had been authorised.

The Appeal Tribunal rejected that argument. It held that the special resolution authorised three distinct categories of work, including 'roofing' as a separate concept, not merely 'roofing repairs'. On that basis, the owners corporation was authorised to undertake the re-roofing works, and the cost remained an expense of the owners corporation as a whole, to be met in accordance with unit entitlements unless and until a different apportionment resolution was passed.

In a Class B scheme, do not assume the owners corporation is responsible just because it has dealt with similar issues before. Check whether there is a valid special resolution and what it covers.

Step 4: Use this checklist

Final takeaway

A practical review of these matters at the outset can save considerable time, cost and frustration later for unit owners. In ACT strata schemes, repair responsibility is rarely determined by assumption or by who happens to use the affected area day to day. It depends on the units plan, the statutory framework, the classification of the scheme and, in Class B developments, any special resolution that alters the default position.

If there is uncertainty, owners and owners corporations should avoid rushing to conclusions and instead confirm the legal character of the item in question before works are undertaken. Getting that analysis right early can help avoid unnecessary disputes, duplicated costs and the risk of the wrong party carrying out or paying for repairs they were never legally obliged to undertake.

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