Air Conditioners - The Different Types and Who Owns Them

Who owns the air conditioner?

The same shared-versus-individual rule that applies to hot water applies here:

If the air conditioner serves more than one unit, it is common property.
If the air conditioner serves only one unit, it is the owner's.

Where it gets complicated is that the unit may be the owner's, but the installation almost always involves common property for eg, an external wall to bracket the unit, a roof for an evaporative cooler, common-property paths or driveways for the compressor or common ducts for cabling. That is where the corporation's rules come into play, and that is where most of the disputes start.

Strata Title: The common property test

Under Section 5(6) of the Strata Titles Act 1988 (SA), common property includes any pipe, cable, wire, duct, or drain not for the exclusive use of a unit. Section 25 makes the corporation responsible for maintaining all common property in good order. Together these mean that if an air conditioner serves more than one unit, the corporation owns and maintains it.

Community Title: The service infrastructure test

Under the Community Titles Act 1996 (SA), Section 28 defines common property to include service infrastructure, and Section 3 spells out that "service infrastructure" expressly includes air conditioning or ventilation equipment that supplies more than one lot. Section 75 then makes maintenance the corporation's job.

The four main system types

Wall or window units

At the smallest end of the air conditioning market sit self-contained units installed in a window or external wall, suitable for a single room or open-plan area up to roughly 50 m². Smaller models plug into a normal power point; larger ones may need additional wiring. Where the unit hangs from a window or sits in an external wall, the installation involves common property even though the air conditioner itself only serves one unit.

Split systems

Split systems are the most common style installed in strata today. A compressor (the noisy outdoor box) is installed externally, and has one or more indoor air outlets connected by refrigerant pipe and electrical cabling running through the wall. The compressor is almost always mounted on common property, an external wall, a balcony, or a path, which means corporation approval is needed to install.

Ducted systems

Ducted systems provide whole-of-unit cooling through ceiling-space ductwork connected to a large external compressor or roof-mounted unit. In a strata building they're most likely seen in townhouse-style groups or in retrofits where the ceiling void is large enough. Installation almost always involves significant common property, in roof penetrations, structural fixings and ceiling voids, and requires careful corporation approval.

Evaporative coolers

These are best suited to dry inland climates. Hot air is drawn over a water reservoir and the cooled, moistened air is blown into the unit. They're cheap to run but require a water supply and good drainage; so therefore in coastal humidity it does not perform. Roof-mounted evaporative coolers raise the same common-property approval questions as a ducted compressor.

Modern systems often add inverter technology, which is a variable-speed compressor that uses less power than a conventional on-off compressor. Most split systems sold today are reverse-cycle, meaning they heat as well as cool. Reverse-cycle running costs are typically cheaper than electric resistance heating, which is why many groups now favour them over older heater installations.

Approval: Special resolution vs unanimous resolution

This is the part that catches owners out. Installing an air conditioner often requires the corporation's approval and the threshold depends on what is being approved.

Approving the installation itself (where it touches common property, for example, a compressor mounted on an external wall) typically requires a special resolution: at least 14 days' written notice, supported by at least two-thirds of the total possible votes assuming every unit holder attended.
Granting the owner exclusive use of an area of common property (for example, the slab the compressor sits on) requires a unanimous resolution: a special resolution passed without a single dissenting vote. Exclusive use of common property is not something a corporation can hand out by majority, the Acts deliberately set the bar high.

If your group is fielding a lot of A/C requests, the practical answer is to set a policy once and apply it consistently. See the sample below.

Common installation problems

Compressor on a path or driveway. These can be a trip hazard at night and vulnerable to vehicle damage. Bollards or relocation usually fix it.
Improvised drain plumbing. An old garden hose dribbling condensate down a wall is the giveaway. Have it plumbed properly into existing pipework.
Window-hung units sagging from the frame. These are often installed without brackets or load support. Both are unsafe and a sign that the install was never approved.
Compressor noise. Most modern split systems run well under 45 dB at 1 metre (about the sound of a quiet library), but older units, poorly mounted units or units running 24/7 can create real friction with neighbours. Mounting quality and placement often matter more than the spec sheet rating.

Maintenance tips

For evaporative coolers specifically:

Cover the unit during winter to extend equipment life and reduce drafts.
Replace water and clean the pads before each summer. Sediment, fungus and algae build up over time and reduce both efficiency and air quality.
Disinfect every six months for groups in continuous use.
After summer: disconnect power, clean the basin and waterways, dry the internal parts by running the fan, and refit waterproof covers.

For split systems, an annual professional clean of the indoor unit and a check of the gas charge will catch most faults before they leave the unit running but not cooling.

A sample air conditioner policy

The following is a starting point your corporation can adapt - both Acts allow your group to set this kind of standing rule by special resolution.

Approval requirement (special resolution):
Unit holders may install a wall-mounted or split-system air conditioner, provided the unit is not mounted on the frontage of the unit or impeding any common walkway, is a low-noise rotary compressor model creating no more than 45 dB at 1 metre, and complies with EPA requirements current at the time of installation.
Or: Unit holders may install a roof-mounted air conditioner, provided it is mounted below the ridgeline at the rear of the building, is similar in colour to the roof, creates no more than 45 dB, and complies with EPA requirements current at the time of installation.

For community-title groups arranged lot beside lot, refer to your by-laws first. If the by-laws are silent on air conditioners or building appearance, owners can usually proceed without approval as the Community Titles Act gives lot owners more autonomy than strata gives unit holders.

Get in touch

If you're working through an air conditioner approval, drafting a policy, or fielding a noise complaint, we're happy to help. Acacia Collective manages strata and community title groups across South Australia.

Call us on 1300 792 255 or email hello@acaciacollective.com.au.