Smoke alarm installation

12 min read

Learn how many smoke alarms you need in your home, and where and how to install them.

Summary

  • By law, smoke alarms must be installed between each sleeping area and the rest of the house, and on each floor.
  • Bedroom fires when people are sleeping are the most deadly.
  • CFA recommends you put smoke alarms in every bedroom and living area to give you more time to escape a fire.
  • Install smoke alarms away from walls and corners.

Where to install smoke alarms

By law, smoke alarms must be installed between each sleeping area and the rest of the house. Due to recent research, CFA recommends you go further and put smoke alarms in every living area and every bedroom as well.

Legally required smoke alarms

Victorian law has minimum requirements for the number and location of smoke alarms in homes.

Single storey homes, including apartments, units and caravans

According to Victorian law, there must be a smoke alarm between each sleeping area and the rest of the house.

Multi-storey homes

By law, in multi-storey homes:

  • there must be a smoke alarm between each sleeping area and the rest of the house.
  • there must be a smoke alarm on every floor of a multi-storey home, including floors with no bedrooms.
    • If there are no bedrooms upstairs, a smoke alarm must be located near the top of the stairs.
    • If there are bedrooms upstairs, then a smoke alarm must be positioned near the inter-connecting stairs on the ground floor.
  • smoke alarms should be installed on the path people would take when leaving during an emergency.

CFA recommends smoke alarms in every bedroom and living room

An image in three panels, showing an adult's bedroom, a lounge room and a child's bedroom, each with a smoke alarm on the ceiling.
CFA recommends a working smoke alarm in every bedroom and living area.

CFA recommends going beyond what's required by law. The more smoke alarms you have, the sooner you know there's a fire, and the sooner you can escape.

CFA recommends installing a working smoke alarm in every bedroom and every living area.

This is because we know that fires in bedrooms are the most deadly—more people die in house fires which start in the bedroom than anywhere else in the home.

We also recommend putting smoke alarms in rooms where you charge devices and equipment, such as the garage.

Example floor plans

A floor plan of a 3-bedroom double storey home. Blue circles indicate where smoke alarms must be installed by law, outside two sleeping areas and in a stairwell. Yellow circles indicate where extra smoke alarms should be installed for better protection, inside three bedrooms and the living room.
In this floor plan of a 3-bedroom double storey unit, blue circles indicate the minimum legally required smoke alarms, outside sleeping areas and at the bottom of stairs. The yellow circles in every living room and bedroom indicate where CFA recommends installing extra smoke alarms.

CFA has a range of floor plans marked with smoke alarm locations to help you develop a plan for your home.

Each floor plan shows where smoke alarms are legally required (blue), and where CFA recommends putting extra smoke alarms (yellow). Find a selection of floor plans below.

Your exact floor plan might not be here. In that case, apply the principles on this page to your own floor plan.

2 Bedroom Home

 

2 Bedroom, Single Storey

A floor plan of a 2-bedroom single storey home. A blue circle indicates where a smoke alarm must be installed by law, outside the two bedrooms clustered together. Yellow circles indicate where extra smoke alarms should be installed for better protection, inside the two bedrooms.

In this two bedroom, single storey home one smoke alarm (blue) is required by law directly outside the two bedrooms that are clustered together. Because the two bedrooms are close together, one smoke alarm can legally cover both rooms.

CFA recommends installing an additional smoke alarm (yellow) inside each of the bedrooms because, if a fire starts inside the bedroom, the extra smoke alarm is more likely to detect the smoke than the one outside the bedrooms.

2 Bedroom, 2 Storey

A floor plan of a 2-bedroom double storey home. Blue circles indicate where smoke alarms must be installed by law, outside the two bedrooms on the top floor and in the stairwell on the ground floor. Yellow circles indicate where extra smoke alarms should be installed for better protection, inside two bedrooms and the living room.

This two bedroom, double storey home requires (blue) one smoke alarm outside the two bedrooms on the top floor. As the two bedrooms are close together, one smoke alarm can legally cover both bedrooms. Because the home has two storeys, an additional smoke alarm is required by law in the stairwell on the ground floor.

CFA recommends installing an additional smoke alarm (yellow) inside each of the bedrooms because, if a fire starts inside the bedroom, the extra smoke alarm is more likely to detect the smoke than the one outside the bedrooms. We also recommend installing an additional smoke alarm in the living room because most fatal fires start in either a bedroom or living area.

3 Bedroom Home

3 Bedroom, Single Storey

A floor plan of a 3-bedroom single storey home. A blue circle indicates where a smoke alarm must be installed by law, outside the three bedrooms clustered together. Yellow circles indicate where extra smoke alarms should be installed for better protection, inside three bedrooms and the living room.

This three bedroom, single storey home requires (blue) a single smoke alarm outside the 3 bedrooms that are clustered together around a hallway. As the bedrooms are close together, one smoke alarm can legally cover all three bedrooms.

CFA recommends installing an additional smoke alarm (yellow) inside each of the bedrooms because, if a fire starts inside the bedroom, the extra smoke alarm is more likely to detect the smoke than the one outside the bedrooms. We also recommend installing an additional smoke alarm in the living area because most fatal fires start in either a bedroom or living area.

3 Bedroom, 2 Storey

A floor plan of a 3-bedroom double storey home. Blue circles indicate where smoke alarms must be installed by law, outside the three upstairs bedrooms clustered together and in the stairwell on the ground floor. Yellow circles indicate where extra smoke alarms should be installed for better protection, inside three bedrooms and the living room.

This three bedroom, double storey home requires (blue) one smoke alarm outside the three bedrooms on the top floor. As the three bedrooms are close together, one smoke alarm can legally cover both bedrooms. Because the home has two storeys, an additional smoke alarm is required by law in the stairwell on the ground floor.

CFA recommends installing an additional smoke alarm (yellow) inside each of the bedrooms because, if a fire starts inside the bedroom, the extra smoke alarm is more likely to detect the smoke than the one outside the bedrooms. We also recommend installing an additional smoke alarm in the living room because most fatal fires start in either a bedroom or living area.

3 Bedroom, 3 Storey

A floor plan of a 3-bedroom, three storey home. Blue circles indicate where smoke alarms must be installed by law, one outside the bedroom on the ground floor, one outside each of the separated bedrooms on the top floor, and in the stairwell on the middle floor living area. Yellow circles indicate where extra smoke alarms should be installed for better protection, inside the four bedrooms, in the living room and in the garage.

This three bedroom, three storey home requires (blue) one smoke alarm outside bedroom three, on the ground floor. It also requires a smoke alarm outside each of the two bedrooms on the top floor. As the two bedrooms on the top floor are some distance apart, they each require their own smoke alarm outside the bedroom door. Because the home has three storeys, an additional smoke alarm is required by law in the stairwell on the middle floor. The same rule would normally require another smoke alarm at the bottom of the stairs on the ground floor, however the smoke alarm outside bedroom three already serves that purpose.

CFA recommends installing an additional smoke alarm (yellow) inside each of the bedrooms because, if a fire starts inside the bedroom, the extra smoke alarm is more likely to detect the smoke than the one outside the bedroom. We also recommend installing an additional smoke alarm in the garage, and one in the living room because most fatal fires start in either a bedroom or living area.

4 Bedroom Home

4 Bedroom, Single Storey

A floor plan of a 4-bedroom single storey home. Blue circles indicate where smoke alarms must be installed by law, outside each group of bedrooms at opposite ends of the house. Yellow circles indicate where extra smoke alarms should be installed for better protection, inside the four bedrooms and the living room.

This four bedroom, single storey home requires (blue) a single smoke alarm outside the 3 bedrooms that are clustered together adjoining the living room. As the bedrooms are close together, one smoke alarm can legally cover both bedrooms. It also requires a single smoke alarm outside the two bedrooms clustered at the other end of the house.

CFA recommends installing an additional smoke alarm (yellow) inside each of the bedrooms because, if a fire starts inside the bedroom, the extra smoke alarm is more likely to detect the smoke than the one outside the bedrooms. We also recommend installing an additional smoke alarm in the living area because most fatal fires start in either a bedroom or living area.

4 Bedroom, 2 Storey

A floor plan of a 4-bedroom double storey home. Blue circles indicate where smoke alarms must be installed by law, one outside the master bedroom on the ground floor, one outside the three bedrooms on the second floor, and one in the stairwell on the ground floor. Yellow circles indicate where extra smoke alarms should be installed for better protection, inside each of the four bedrooms, in the upstairs living room and in the home theatre.

This four bedroom, double storey home requires (blue) one smoke alarm outside the three bedrooms on the top floor. As the three bedrooms are close together, one smoke alarm can legally cover all three bedrooms. Another smoke alarm is required outside the master bedroom at the far end of the ground floor. Because the home has two storeys, an additional smoke alarm is required by law in the stairwell on the ground floor.

CFA recommends installing an additional smoke alarm (yellow) inside each of the bedrooms because, if a fire starts inside the bedroom, the extra smoke alarm is more likely to detect the smoke than the one outside the bedrooms. We normally also recommend installing an additional smoke alarm in the living room because most fatal fires start in either a bedroom or living area. However, the smoke alarm outside the master bedroom will serve this purpose. We do, however recommend installing an additional smoke alarm inside the home theatre and in the upstairs, separate living area.

4 Bedroom, 3 Storey

A floor plan of a 4-bedroom, three storey home. Blue circles indicate where smoke alarms must be installed by law. One smoke alarm outside the ground floor bedroom, one outside the two bedrooms clustered on the top floor, and one outside the master bedroom at the other end of the top floor. An extra smoke alarm is required on the middle floor near the stairwell. Yellow circles indicate where extra smoke alarms should be installed for better protection, inside the four bedrooms and the garage.

This four bedroom, three storey home requires (blue) one smoke alarm outside bedroom four, on the ground floor. It also requires a smoke alarm outside the master bedroom on the top floor. Another smoke alarm is required outside the other two bedrooms on the top floor. As the two sleeping areas on the top floor are some distance apart, they each require their own smoke alarm. Because the home has three storeys, an additional smoke alarm is required by law in the stairwell on the middle floor. The same rule would normally require another smoke alarm at the bottom of the stairs on the ground floor, however the smoke alarm outside bedroom four already serves that purpose.

CFA recommends installing an additional smoke alarm (yellow) inside each of the bedrooms because, if a fire starts inside the bedroom, the extra smoke alarm is more likely to detect the smoke than the one outside the bedroom. We also normally recommend installing an additional smoke alarm in the living room because most fatal fires start in either a bedroom or living area. However, the smoke alarm that serves the stairwell on the middle floor will do. We do recommend installing another smoke alarm in the garage.

Guidelines for installing smoke alarms

Hands installing a white smoke detector on a ceiling.

The ideal location for a smoke alarm is the centre of a ceiling, away from walls and corners.

Do not install smoke alarms near the highest point of cathedral or sloping ceilings, the corner junction of walls and ceilings or between exposed floor joists. Smoke can trap a pocket of clean air in corners like these, meaning that a smoke alarm in the corners may not detect smoke. These locations are called 'dead air spaces'.

Do not install smoke alarms near windows, doors or air ducts where drafts could affect alarm sensitivity.

Ceiling installation

Illustration showing a smoke alarm on a flat ceiling, avoiding the dead air spaces in the corners where the walls meet the ceiling. An alternative location is indicated on the wall between 30cm and 50cm from the ceiling if you can't put one on the ceiling.

Smoke alarms should be located in the centre of the ceiling. If it can't be located in the centre, it should be 30cm from any corner or wall.

Wall installation

Illustration showing a smoke alarm on the wall between 30cm and 50cm from the ceiling if you can't put one on the ceiling. It indicates a dead air space to avoid, within 30cm from the ceiling.

If it's not possible to install a smoke alarm on the ceiling, you can install one high up on a wall. Smoke alarms on walls should be located 30cm - 50cm from the ceiling.

Cathedral ceiling or sloping ceiling installation

Illustration showing a smoke alarm on a cathedral ceiling, avoiding the dead air space 50cm from the top apex of the ceiling. It shows the smoke alarm installed between 50cm and 150cm max from the top of the ceiling.

Smoke alarms on cathedral or sloped ceilings should be located 0.5m - 1.5m from the highest point.

hide

How to install a smoke alarm

In this video, you will learn how to install a battery powered smoke alarm in your home.

Don't open or break smoke alarms

Some smoke alarms contain a very small amount of radioactive material. It is safe within the smoke alarm and won't hurt you. But do not open, dismantle or break smoke alarms when disposing of them as the radioactive material may be exposed.

Household quantities of smoke alarms can be placed into your general household waste for normal kerbside pickup.

Resources

 

Page last updated: Thursday, 3 September 2026 5:15:24 PM

Other topics you may be interested in:

Garages and sheds

Learn how to prevent fires starting in your garage or shed, including storing chemicals and charging electrical equipment safely.

Tagged with Home fire safety

Read article

Click through to Garages and sheds

Renters rights and responsibilities

Learn the rights and responsibilities of renters when it comes to fire safety in your home, including smoke alarms, gas and electricity.

Tagged with Home fire safety

Read article

Click through to Renters rights and responsibilities

Advice for rental providers

Learn your responsibilities as a rental provider when it comes to smoke alarm, gas and electricity safety.

Tagged with Home fire safety

Read article

Click through to Advice for rental providers

What to do if your house catches fire

It's important you know what to do if a fire starts in your home. Learn when to try and put a fire out, and when to get out and call Triple-Zero (000).

Tagged with Home fire safety

Read article

Click through to What to do if your house catches fire