How to Wire a Smart Home in Australia

The smart home conversation usually starts with devices: which switches, which sensors, which voice assistants. The wiring conversation should come first. The choices you make about cabling, neutral wires, and conduit at construction time determine what’s possible later, and what you’ll end up paying to retrofit.

New build vs retrofit, the central question

If you’re building or renovating, you have one chance to specify the right cabling. Once the gyprock is up, the cost of retrofitting cable rises by 10–20× per metre. Some retrofits become effectively impossible without ceiling access.

If you’re retrofitting an existing house, your options are constrained by what’s already in the walls. Most older Australian homes have wiring that pre-dates any smart home thinking: no neutrals at switches, no data cabling, no conduit for future runs. Retrofit work is about making the most of what’s there, not chasing new-build ideal.

What every smart home install needs in the wall

Three things, roughly in order of importance.

1. Neutral wires at every switch

This is the single biggest wiring decision in a smart home. Old Australian wiring practice routed only “active” wires through switches, a practice called “loop at switch” or “switch loop.” It saved cable but means smart switches have no power source when the load (light) is off.

Modern smart switches need continuous power to run their radio and processor, even when the light is off. Without a neutral at the switch, your options are:

• Battery-powered switches (cheaper, but batteries to replace every 2–3 years)
• Smart switches in the ceiling next to the light (requires ceiling access for service)
• Specific brands of “no-neutral” smart switches (limited selection, often unreliable on LED loads)

If you’re new-building or rewiring, specify neutrals at every switch position. This is an electrician’s standard request. It adds maybe 5% to wiring costs and removes a major future constraint.

2. Data cabling to key locations

Wi-Fi will not solve every networking problem in a house. Cabled Ethernet to specific endpoints is the difference between a system that performs reliably and one that has mysterious slowdowns no one can debug.

Where to specify Cat6A or Cat6 (Cat6A is the better choice for new builds: handles 10 Gbps over longer runs):

• Home Assistant controller location. Non-negotiable, must be wired.
• Wi-Fi access point locations. Typically one per 80–100 m² of habitable space, mounted on ceilings.
• TV and media locations. Every TV gets a cable run; smart TVs and streaming boxes work better wired.
• Camera locations. Both for fixed cameras and for future PoE additions.
• Office and study locations. Cat6A provides the option of high-speed wired connection.
• Comms cabinet. Central termination point for all cabling, sized for current needs plus 50%.

Specify two cables to each TV location, two to the comms cabinet from each access point, and one to every other endpoint. The marginal cost of doubling up at construction time is trivial. Going back later is expensive.

3. Conduit between key locations

Even the best wiring spec can’t predict 2035. Specify 25mm or 32mm conduit between:

• The comms cabinet and the roof space
• The comms cabinet and the underfloor (if accessible)
• The garage and the comms cabinet (for EV charging in future)
• Any external building (granny flat, pool shed) and the main house

Conduit lets you pull new cable later without opening walls. It’s the single highest-value future-proofing decision. Cost at build time is minor; cost of retrofit conduit is substantial.

Comms cabinet, what to specify

The comms cabinet is where your network lives. Get it right at build time and everything else slots in around it.

Specifications:

• Location: Ground floor, away from external walls (for temperature stability), accessible without going through a child’s bedroom
• Size: 12U rack-mount minimum for new builds; 6U if space-constrained
• Power: Two 240V GPOs in the cabinet, ideally on a dedicated circuit with surge protection
• Cooling: Fan-cooled with a thermostat, or located somewhere with passive cooling (not in a sealed cupboard)
• Cabling: All Ethernet runs terminate to a patch panel at the top of the cabinet
• Future-proofing: Conduit access from above (to roof) and below (to underfloor)

Equipment that goes in:

• Multi-WAN router (Peplink Balance series typical)
• Patch panel for all Ethernet runs
• Network switch (24-port managed, PoE+ for cameras and access points)
• Home Assistant controller
• UPS (uninterruptible power supply). A 1000VA unit keeps the network running for 30+ minutes during a grid outage.
• NVR if running cameras
• Any vendor hubs (Hue Bridge, Lutron Bridge, etc.)

The total power draw is around 50–100W continuous. Plan accordingly.

What goes in software, not in the wall

Plenty of smart home features don’t need any special wiring:

• Lighting scenes and schedules. Handled in software once switches are smart.
• Voice control. Works over Wi-Fi to existing hubs.
• Climate scheduling and zoning. Typically uses the existing thermostat wiring.
• Security system integration. Most modern security panels expose a network API.
• Solar and energy monitoring. The inverter and meter handle the data; software displays it.

The temptation in a new build is to over-specify wiring “just in case.” The discipline is to specify the things that genuinely need physical infrastructure and to leave the software-layer stuff to be configured later.

Retrofit-friendly device choices

If you’re working with existing wiring, certain device types are explicitly designed for retrofit.

Behind-the-switch relays

Shelly, Aqara, and similar brands make small relays that fit inside an existing wall plate cavity, behind the original switch. The original switch keeps working physically; the relay adds smart functionality. If a neutral is available, the relay runs from neutral. If not, “no-neutral” variants exist (with caveats: fluorescent and some LED loads can have issues).

This is the dominant approach for retrofit lighting in older Australian homes. Cost is roughly $40–80 per switch position installed.

Battery-powered sensors

Door/window sensors, motion sensors, leak sensors, environmental sensors, all battery-powered, no wiring required. Use Thread or Zigbee for long battery life. CR2032 or AAA batteries last 2–5 years.

Wireless plugs

For lamps and appliances, smart plugs that fit in existing GPOs are the simplest retrofit. The Australian market has limited selection; importing from European or US brands risks compatibility issues. Stick to Australian-certified products (the Aqara range is reliable).

Battery-powered locks

Smart locks for front doors, garage doors, and gates run on AA or rechargeable batteries. Battery life is 6–18 months depending on usage. No wiring changes required.

What licensed work looks like

Several aspects of smart home installation are licensed electrical work:

• Replacing wall switches with smart switches (changes the fixed wiring)
• Installing behind-the-switch relays (work inside fixed wiring)
• Adding new circuits, neutrals, or data cabling within fixed wiring
• Installing or modifying the comms cabinet’s mains supply

These require a Queensland Electrical Contractor licence, which Iron and Air holds, or a registered cabler licence for low-voltage data work. AC mains work is delivered directly by Iron and Air. Grid-connected solar with battery storage that requires SAA accreditation is coordinated through accredited partners until SAA accreditation issues.

What an unlicensed person can legally do:

• Use plug-in smart devices
• Install battery-powered sensors
• Configure Home Assistant and software automations
• Set up cameras (if PoE-powered, no mains work)
• Install Wi-Fi access points (if powered by PoE, not requiring new cabling)

Common questions

Can I do my own data cabling? Communications cabling in Australia requires registered cabler certification. You can run cables yourself within your own home for personal use, but if anything is connected to the public network (NBN, telephone), it must be done by a registered cabler. The certification is straightforward to obtain but not free. For most homeowners, hiring a registered cabler is the practical answer.

What’s the minimum wiring for a “smart-ready” new build? Neutrals at every switch, Cat6A to every key endpoint, conduit between major zones, a 6U comms cabinet with dedicated power. This adds typically 1–2% to the overall electrical and data cost of a new build and removes most future constraints.

My house was built in 2015. How much retrofit wiring will I need? Probably less than you think. Most 2015+ Australian homes have neutrals at switches (the regulation changed mid-2010s), data cabling to most rooms, and reasonable provision in the meter cabinet. The gaps are usually around comms cabinet sizing, ceiling access for AP installation, and conduit for future runs.

Should I install Cat7 or fibre instead of Cat6A? Cat6A handles 10 Gbps over 100 m, which is more than any home currently uses and probably any home will use in the next 15 years. Cat7 and fibre are overkill for residential. Cat6A is the right specification for new builds.

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