What does a residential electrical safety inspection actually check?

An electrical safety inspection gets booked for different reasons — a property purchase, a rental handover, a concern about old wiring, an insurance requirement, or just a home that hasn't been looked at in twenty years. The value of the inspection depends entirely on how thoroughly it's done and how clearly the findings are communicated.

Here's what a proper residential electrical safety inspection should cover, circuit by circuit and system by system.

What we're looking for before we test anything

The first part of an inspection is visual — working through the property systematically, looking at anything electrical that's accessible. This isn't a superficial pass. It's a structured check against known failure modes.

Switchboard condition

The switchboard is where the inspection starts. We're assessing:

Device types and age. Ceramic fuse holders are a sign of an older installation that predates modern overcurrent protection standards. Rewirable fuses are the same era. Early MCBs from the 1980s are still functional but may not meet current ratings. Modern RCBOs are what a current-standards board should have.

RCD protection. Is every circuit protected by an RCD or RCBO? This is a code requirement for any circuit modified or added after the relevant edition of AS/NZS 3000 came into force, and it's a practical safety requirement for any home. A single shared RCD upstream of multiple circuits provides some protection but is not the same as per-circuit protection.

Physical condition of the board. Burn marks, discolouration, melted insulation, loose cable entries — any of these indicates a board that has had a problem. A board with heat damage is a board that needs replacement, not just an MCB swap.

Labelling. Circuits should be clearly labelled so you know which breaker controls which part of the house. Unlabelled circuits are a practical problem and indicate a board that hasn't been properly commissioned.

Space and capacity. If your board is full and you're planning an EV charger or solar installation, the inspection will flag that early.

Visible wiring

We look at any wiring that's accessible — in the roof space, under the house, in the meter box, and at accessible junction points. We're looking for:

• Degraded insulation. PVC insulation from the 1960s and 1970s can become brittle and crack. Rubber insulation from even earlier is more fragile still. Anywhere the insulation has cracked or split, there's an exposed conductor that poses a shock and fire risk.
• Incorrect cable type or rating. A circuit that's been extended with undersized cable — someone's done-it-yourself extension in the roof — is a common finding in homes with mixed history.
• Mechanical damage. Cables that have been pinched, compressed, or run over a sharp edge. Rodent damage. Cables that have been penetrated by a screw or nail during a renovation.
• Water ingress. Wiring in wet areas, or wiring that's been exposed to roof leaks, can have degraded insulation and compromised connections that won't show up under normal operation until they fail.
• Aluminium wiring. Common in Melbourne homes built 1970–1985. Not automatically dangerous, but requires specific attention at connection points. If aluminium wiring is found, the inspection will note its extent and condition.

Outlets, switches, and fixed fittings

Every accessible power outlet, switch, and fixed fitting gets a visual check. Cracked faceplates, outlets that are loose in the wall, switches that feel hot to the touch — these are common findings in older homes and they matter.

In wet areas — bathrooms, laundries, kitchens — we check that any outlets are correctly rated and positioned. An outlet within reach of a shower isn't compliant under current standards and is a hazard regardless of compliance history.

Exhaust fans, fixed heaters, and ceiling fans get checked for correct installation and, where accessible, correct wiring.

Smoke alarms

We check that smoke alarms are present on each storey and that they're the correct type. Since 2017, Victoria has required photoelectric smoke alarms — ionisation-only alarms do not meet current requirements. We check whether alarms are hardwired or battery-operated, whether they're interconnected, and whether any are past their replacement date (most photoelectric alarms have a 10-year service life from manufacture date, printed on the unit).

The electrical tests

Visual inspection identifies obvious problems. Testing finds the ones that aren't visible.

Insulation resistance testing

We test the insulation resistance of each circuit using a test instrument that applies a DC voltage (typically 500 V for a 230 V installation) and measures the resistance between the conductors and earth. The result tells us whether the insulation is intact.

A healthy circuit will show insulation resistance in the hundreds of megaohms or higher. A circuit showing a few megaohms has degraded insulation. A circuit showing below 1 megaohm has a problem that needs investigation — it may be a wiring fault, damaged insulation, or a faulty appliance left plugged in (we test with appliances disconnected).

This test catches deterioration that has no visible symptom. Old cable insulation can look intact on the outside and measure poorly — the degradation happens from the inside, in the PVC compound, and the surface looks fine until it's quite far gone.

Earth continuity testing

Every circuit needs a continuous protective earth back to the main earthing point at the switchboard and from there to the main earthing system. We verify this on each circuit with a low-resistance test. Broken earth conductors, corroded connections, or improperly terminated earth wires will show up here.

An incomplete earth doesn't cause a problem during normal operation. It becomes critical the moment a fault develops — the protective earth is what causes the breaker to trip quickly and safely when an active conductor contacts exposed metalwork. Without a complete earth, that protection is absent.

RCD trip time testing

Every RCD and RCBO gets tested for trip time at 30 mA. Australian standards require that an RCD operating at its rated current trips within 300 milliseconds — but in practice, a properly functioning modern device trips in 30 milliseconds or less. A device that's taking 200+ milliseconds to trip at 30 mA is still technically within spec but is at the slow end of acceptable, and it's worth noting.

We also test at higher fault currents to verify the trip response. RCDs have a mechanical trip mechanism that can stick with age — testing is the only way to know whether the device will actually operate under fault conditions. A visual inspection of a 15-year-old RCD tells you very little about whether it will trip when needed.

Polarity checking

Each outlet is checked for correct polarity — active to active pin, neutral to neutral pin. Reversed polarity is more common than it should be, particularly in homes where amateur work has been done at some point, and it means that switching off an appliance at the wall switch may not disconnect the active conductor.

What the report covers

At the end of the inspection, you get a written report that covers each system and each finding. The findings are categorised:

Immediate hazards — conditions that pose a current risk and need rectification before the property is occupied or before the relevant system is used. A live conductor with damaged insulation in an accessible location is an immediate hazard. A board with heat damage is an immediate hazard.

Defects requiring rectification — conditions that don't meet current standards and need to be fixed, but where the immediate risk is lower. Missing RCD protection on a circuit that hasn't been modified since it was installed may not be an immediate hazard but it's a defect that needs addressing.

Observations — items worth monitoring or planning for, not urgent but worth knowing. Ageing wiring that tests adequately now but is approaching end of practical life. A board with no room for additional circuits. Smoke alarms approaching their replacement date.

The report doesn't just list problems. It gives you enough context to understand what each finding means and what the remediation options are. If something needs fixing urgently, we'll say so and explain why.

Who needs an inspection

Buyers of older homes. Properties built before 1990 in the eastern suburbs — Box Hill, Mitcham, Ringwood, Blackburn, Bayswater and surrounding suburbs — will commonly have wiring from an era before current safety switch requirements, and sometimes wiring from an era before modern circuit breaker standards. An inspection gives you an independent picture of the electrical system before you commit.

Landlords. Victorian legislation requires rental properties to be maintained in a safe condition. Electrical safety is part of that obligation. An inspection provides documented evidence that the property has been assessed, and the report identifies anything that needs rectification before tenants move in.

Homeowners in older properties. If you've been in your home for decades and the wiring hasn't been looked at, an inspection is worth doing. The system may be fine, or it may have issues that have been quietly developing that you wouldn't know about without testing.

Anyone planning renovation work. If you're about to open walls, add circuits, or do any work that will affect the electrical system, an inspection first establishes a baseline and identifies anything that needs to be addressed during the renovation rather than after.

If you're in the eastern suburbs and want to know what condition your home's electrical system is actually in, book a safety inspection and we'll give you a straight answer.