Smoke alarm installation, testing and compliance
Required in every NSW home, with specific obligations if you rent the property out. Straightforward to get right, expensive to get wrong.
What NSW actually requires
Every home in NSW must have working smoke alarms. Beyond that baseline, the detail matters:
- Placement. On every storey, and in the path of travel people would use to exit — which in practice means hallways outside bedrooms. A single alarm in a central hallway does not cover a two-storey home or a long single-storey one.
- Hardwired in newer homes. Homes built or significantly renovated since 2006 generally require mains-powered alarms with battery backup, rather than battery-only units.
- Ten-year replacement. The sensor degrades whether or not the battery is fine. Alarms have a manufacture date printed on them and must be replaced within ten years of it.
- Landlord obligations. If you rent the property out, alarms must be checked annually, and repairs or replacements have specific timeframes. Records matter.
The requirement people most often miss is the ten-year one. An alarm that beeps when you press the button can still be well past its usable life.
Why interconnection is worth doing
Interconnected alarms all sound when any one of them detects smoke. Standalone alarms only sound where the smoke is.
That distinction matters more in the Hills than in an inner-city terrace, because the housing stock is bigger. A single-storey home sprawling across a large block can easily have 20 metres and two closed doors between the kitchen and the far bedroom. An alarm going off in the kitchen at 3am may simply not wake someone at the other end. Interconnected alarms remove that problem entirely.
It can be done with hardwired interconnection where cabling allows, or wirelessly, which is far less disruptive in an existing home with no roof access above every hallway.
What smoke alarm work costs
Sydney, 2026. Multiple alarms in one visit is meaningfully cheaper per unit.
| The job | Price |
|---|---|
| Replace an existing hardwired alarm, like for likeSame position, existing wiring | $150 – $260 |
| Photoelectric alarm supplied and installedMains powered with battery backup | $180 – $320 each |
| Wirelessly interconnected alarm setPer alarm, in a set. Avoids cabling through finished ceilings | $200 – $350 each |
| Whole-home replacement, 4–6 alarmsThe common job when a house hits the ten-year mark | $700 – $1,600 |
| Annual rental compliance checkTest, document and report. Per property | $120 – $220 |
| Bulk rental portfolio pricingMultiple properties scheduled together | ask |
These are indicative market ranges for Sydney in 2026, not a quote. What you pay depends on your switchboard, access and what we find. We confirm a fixed price before starting, and it doesn't move.
For property managers and landlords
If you manage rental properties, the annual smoke alarm obligation is a scheduling problem more than a technical one — and it's the kind of thing that only becomes visible when something goes wrong.
We can work through a portfolio on a schedule rather than property by property, and provide a written compliance report per property with alarm locations, manufacture dates, test results and anything replaced. That gives you a document to file rather than a line on an invoice.
If you'd rather see a sample report before committing anything, ask and we'll send one.
Smoke alarm questions
How many smoke alarms do I need in NSW?
At minimum, one on every storey in the path of travel to an exit — in practice, hallways outside bedrooms. Larger or sprawling homes need more, and bedrooms themselves are recommended. We'll work out placement rather than fitting the minimum.
Do smoke alarms have to be hardwired in NSW?
Homes built or significantly renovated since 2006 generally require mains-powered alarms with battery backup. Older homes may lawfully have battery-only alarms, though hardwired and interconnected is substantially better.
How often do smoke alarms need replacing?
Every ten years from the manufacture date printed on the unit, regardless of whether it still beeps. The sensing element degrades over time and a test button only confirms the horn and battery work.
My smoke alarm chirps at night. Why always at night?
Low-battery chirping is temperature sensitive, and the coldest point of the day is usually the early hours — that's when a marginal battery finally drops below threshold. Genuinely the reason, and it's not just bad luck.
What are my obligations as a landlord?
Alarms must be working, checked annually, and repaired or replaced within specified timeframes. Keep records. We provide a written report per property so there's documentation rather than recollection.
Photoelectric or ionisation?
Photoelectric. They respond considerably faster to smouldering fires, which is the type most likely to occur in a home at night, and they're less prone to nuisance alarms from cooking.
Can I install smoke alarms myself?
Battery-only units, yes. Mains-powered hardwired alarms are electrical installation work and must be done by a licensed electrician.
What customers say
Fantastic service! Friendly, efficient and well priced. Highly recommend. Thank you for swiftly fixing our switches.
Jason onsite quickly and completed the work on the spot, giving us a good price and was very polite. Would highly recommend.
Reliable and quality service.
These are Google reviews for our team at Cync Electrical & Automation — the licensed contractor behind Hills Electrician. 5.0 from 20 reviews. — see the profile
Rental property due for its annual check?
We can schedule a portfolio and provide a report per property. Call 0422 253 379.
Get a quote