Electrical defects in new homes — warning signs and what to do

Electrical defects in new homes range from the mildly annoying (a power point in the wrong position) to the genuinely dangerous (missing safety switches, incorrectly wired circuits). For a full systematic walkthrough of what to check at handover, see our practical completion inspection checklist — and check plumbing defects at the same time since both are often missed together. Unlike a leaking tap or cracked tile, electrical defects can cause harm — and they can do so without visible warning.

Most electrical defects in new builds come from one of three sources: incorrect installation, missed items in the contract, or work that doesn’t comply with Australian Wiring Rules (AS/NZS 3000). Catching them at handover, before you sign off on practical completion, is the most effective and lowest-cost approach.

Why electrical defects deserve priority attention

Electrical defects that might seem minor — a tripping circuit, a switch that doesn’t respond, a missing safety switch — can indicate underlying problems that aren’t safe to ignore:

• A circuit that trips repeatedly may indicate overloading, a wiring fault, or an incorrectly sized breaker
• A missing RCD (residual current device / safety switch) means there’s no protection against electrocution from a fault in that circuit
• Incorrect switchboard labelling means the wrong circuit might be isolated in an emergency

Treat all electrical defects as a priority in your handover checklist — not because every one is dangerous, but because you can’t tell which ones are without investigation.

The most common electrical defects in new builds

1. Incorrectly labelled or unlabelled switchboard circuits

Your switchboard should have every circuit clearly labelled — “Kitchen power,” “Bedroom 1 lights,” “Outdoor power,” and so on. In practice, new builds frequently have circuits labelled generically (“Lights 1,” “Power 2”) or not labelled at all.

While not immediately dangerous, incorrect labelling becomes a serious problem in an emergency when you need to isolate a specific circuit quickly. It also makes future electrical work harder and more expensive because an electrician needs to trace circuits before working.

At handover, open the switchboard and check that every circuit has a clear, specific label. Ask the builder’s electrician to correct any that are missing or wrong before you sign off.

2. Non-functional power points or switches

The simplest check — and the one most homeowners overlook — is to test every single power point and light switch in the house. Bring a phone charger and plug it into every power point in every room. Turn every switch on and off.

Non-functional power points in new builds are usually caused by wiring that wasn’t connected at the back of the socket, or a loose connection at the circuit board. They’re quick to fix when caught at handover. After you’ve moved in, furniture is often placed in front of power points, and a fault in the wall behind a couch might not be discovered for years.

3. Missing or incorrectly installed safety switches (RCDs)

Under Australian Wiring Rules, safety switches (RCDs) are required on all power circuits, lighting circuits, and other circuits in residential new builds. An RCD monitors the current flowing through a circuit and trips within milliseconds if it detects a fault — protecting against electrocution.

A new home without RCDs on all required circuits is a serious safety deficiency. At handover, ask for the electrician’s compliance certificate (required for all new residential electrical work in Australia) and check that RCDs are installed on all circuits.

Test the RCDs by pressing the test button on each one — they should trip and require manual reset.

4. Circuits that trip under normal load

A circuit breaker that trips during normal use is usually a sign of one of three things: the circuit is undersized for the load connected (common in kitchen circuits where multiple appliances run simultaneously), there is a wiring fault in the circuit, or the circuit breaker itself is faulty.

Test kitchen circuits at handover by running the dishwasher, oven, and kettle simultaneously. Test the laundry circuit with the washing machine and dryer. If breakers trip under normal household use, this is a defect to be resolved before occupation.

5. Smoke alarm placement or wiring deficiencies

Australian law requires interconnected smoke alarms in new homes — when one alarm activates, all alarms sound. Alarms must be installed in specific locations (on every level, in hallways leading to bedrooms, and in every bedroom in most states).

Check that smoke alarms are present in all required locations and that they are interconnected (pressing the test button on one should trigger all others). Hardwired alarms should have the power light illuminated.

Smoke alarm compliance is a building approvals requirement — deficiencies here can also affect your insurance.

6. Outdoor power points that aren’t weatherproof

All external power points must be weatherproof-rated (sealed covers). Indoor-rated power points installed in covered outdoor areas, garages, or carports are a code deficiency. They can also be identified by the absence of the hinged waterproof cover flap.

Check every outdoor power point, including in the garage, alfresco area, and garden areas.

7. Insufficient lighting or power point circuits

A new home should have power points in logical locations in every room — typically at least two double power points per room, more in kitchens and home offices. Check that your contract specifications for power point quantities and locations have been met.

Similarly, lighting in each room should match the contract. A study without adequate lighting, or a kitchen with a single batten holder in a ceiling that was supposed to have recessed downlights, is a contract deficiency worth flagging.

8. Hot water system electrical connections

Electric hot water systems need to be correctly wired and earthed. Check that the hot water system has its own circuit on the switchboard, that the circuit is correctly labelled, and that there are no visible signs of poor workmanship at the connection point.

What to check at the practical completion inspection

Work through the electrical check in a systematic order at your practical completion inspection:

1. Switchboard: Open and inspect. Every circuit labelled? RCDs on all required circuits? No loose wires visible?
2. Test every power point: Plug in a charger or a test plug. Every room, every outlet.
3. Test every light switch: On and off, confirm the correct light activates.
4. Run heavy circuits: Kitchen (oven + dishwasher + kettle simultaneously), laundry (washer + dryer).
5. Test RCDs: Press the test button on each safety switch.
6. Check smoke alarms: All present, test button triggers interconnected alarm.
7. Check outdoor points: Weatherproof covers present and sealed.
8. Inspect hot water system connection: Correct circuit, correct labelling.

Photograph anything you find and include it in your defect notice.

How to notify your builder of electrical defects

Electrical defects — particularly those involving safety switches, tripping circuits, or code compliance — should be treated as priority items in your defect notice. Flag them separately from cosmetic items to communicate their urgency.

See our full guide on how to write a defect notice for the right format. Your notice should specify:

• Location (e.g., “main bedroom, north wall, double power point at bedside”)
• What you observed (“power point non-functional — phone charger shows no charge”)
• Any related safety concern (“no RCD protecting circuit 4 (kitchen) per switchboard”)

For safety-critical defects (missing RCDs, tripping circuits), it’s reasonable to specify a shorter rectification timeframe — 10 business days rather than the standard 20–30.

After rectification — verify it

When your builder’s electrician comes to fix electrical defects, re-test each item after they leave. Don’t assume a quick visit means everything has been resolved. Re-plug into every power point that was flagged, re-run the heavy load test on kitchen circuits, and re-test all RCDs.

Keep your original photographic documentation until you’re satisfied every item has been properly fixed.

Key takeaways

• Electrical defects range from inconvenient to genuinely dangerous — treat them as a priority at your practical completion inspection, not as an afterthought.
• Test every power point with a charger, every switch, and run heavy circuits simultaneously to test for undersized breakers.
• Verify that RCDs (safety switches) are installed on all circuits and test each one — a new home without proper RCD coverage is a safety deficiency.
• Check smoke alarms are in required locations, hardwired, and interconnected.
• Incorrectly labelled switchboards, non-weatherproof outdoor power points, and insufficient power point locations are contract deficiencies your builder must remedy.
• Document every issue with a photograph and notify your builder in writing — electrical defects flagged before sign-off are the builder’s cost; after sign-off, they become yours.