Safety in Numbers: How Many Smoke Alarms Does Your Home Need?

The chorus of blaring smoke alarms is not a sound anyone wants to hear, but it’s undoubtedly a lifesaver. As our last line of defense during potential fires, understanding the number of smoke alarms to install is paramount.

Why the Right Number of Smoke Alarms Matters

Smoke alarm installation isn’t merely about fulfilling legal requirements; it’s about ensuring that every nook and cranny of your home gets timely alerts in the unfortunate event of a fire. Here’s why accurate placement and numbers matter:

Timely Detection: Smoke spreads fast, but with interconnected alarms, you’re alerted the moment smoke is detected, allowing for swift action.

Maximising Safety: The right number of alarms ensures no part of your home remains a blind spot, keeping all inhabitants safe. 

Compliance: As of 2022 legislation states all homes being rented out or sold must have smoke alarms installed, to new standards. As of 2027 this will apply to all homes.

Identifying Your Current Smoke Alarm

Based on the latest legislation, your home should be equipped with photoelectric smoke alarms and should be replaced every 10 years.

Photoelectric alarms use a light beam to detect the presence of smoke and are considered more reliable. Do not use alarms with ionisation sensors, as they are no longer compliant with current regulations. If you’re unsure what’s in your home, you can check the manufacturing label which should state if it is an ionisation or photoelectric smoke alarm. This label will also list the manufacturing date. If there’s no visible date, it’s best to replace them to make sure it’s no more than 10 years old. 

TIP: If the label doesn’t specify, look for the radioactive symbol. This may be written in the back of the smoke alarm. This indicates it is an ionisation sensor and should be replaced.

ionisation smoke alarm symbol

Determining the Number of Smoke Alarms You Need

Per Level: At a minimum, each level of your home should have one smoke alarm. 

In Every Bedroom: As we sleep, our senses are dulled. A smoke alarm in every bedroom can be the crucial alert needed in case of a fire.

Hallways and Common Areas: Any hallway that connects bedrooms to the rest of the house should have a smoke alarm.

Living Areas: Spaces such as the living room should also have their own alarms, especially if they house electronics or fireplaces.

Floors Without Bedrooms: Ensure that any storey of your home without bedrooms has at least one alarm installed on the pathway leading to the exit.

Tips from Electrical Contractors in Brisbane

    • Interconnection is Required: The legislation requires smoke alarms be interconnected. When one alarm sounds, all alarms in the home do, ensuring everyone is alerted.
    • Test Regularly: While it’s about the number, functionality is crucial. Make sure to test your smoke alarms regularly. If you’re a landlord, you will have legal requirements to do so.

Ensuring you have the right number of smoke alarms in your home is not just about compliance but about ensuring the safety of your home. From bedrooms to hallways, every alert can be the difference between safety and calamity. 

Your safety is paramount, and at Electrical Contracting Queensland, we’re committed to helping Brisbane homeowners get it right. Need guidance on smoke alarm installation or a professional check-up? Get in touch with our team for trusted expertise. 

Smoke Alarm Calculator

Use our smoke alarm calculator to determine how many smoke alarm your home requires to be safe and compliant. 

It sounds like your smoke alarms are in good condition. They must be replaced every 10 years, so be sure to mark the date in your calendar!


This smoke alarm calculator provides an estimated number of alarms based on general guidelines. The actual requirement for your home may vary and should be confirmed by our team during an on-site visit. For a precise assessment and to ensure full compliance with safety regulations, please contact Electrical Contracting Queensland.

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