Are ionisation alarms still legal in an existing Adelaide house?

An existing ionisation alarm that still works is not automatically an offence, but it is a poor instrument for smouldering furniture and it is the type the fire services have been asking people to move away from. When you replace it, fit a photoelectric alarm that meets AS 3786. New work and a title transfer will push you toward mains power or a ten-year sealed battery, depending on the age of the dwelling.

Who changes the battery in a rental?

The landlord must provide working alarms of the right type and should check them at inspections. A tenant who notices a chirp or a dead unit should report it in writing and should not remove the alarm. Nine-volt swaps on an old replaceable-battery unit are a holding action, not a strategy. A sealed ten-year unit has no annual battery ritual.

Do I need an alarm in every bedroom?

The legal test in South Australia is locations that give people in bedrooms reasonable warning so they can get out. Hallways that serve bedrooms are the usual minimum. The Metropolitan Fire Service and the National Construction Code both push further: bedrooms themselves, every storey, and interconnection on new work. If you are already on a ladder, put them where sleeping people actually are.

Smoke alarms in South Australia: what the law actually requires

Every South Australian home needs working smoke alarms, but the type, the power source and the interconnection rules still depend on when the place was built or sold. Here is the practical requirement, without invented section numbers.

Smoke alarms are the one piece of domestic electrical equipment that South Australia treats as civic furniture. Every home is supposed to have them. Owners and residential landlords are supposed to keep them working. The fine for leaving them out is a few hundred dollars — less than a funeral, more than people like to pay for a forgotten hallway. What the law does not do is hand every 1920s Unley villa the same shopping list as a 2018 Mawson Lakes townhouse. Type, power source and interconnection still depend on when the place was built, when the title last moved, and whether you are doing new work.

This is a practical map as at 2025–26, not a substitute for the Planning, Development and Infrastructure regulations or a fire-service fact sheet on a particular floor plan. We do not invent section numbers we cannot stand behind. Consumer and Business Services handles the rental side. The Office of the Technical Regulator sits behind hard-wired work. A licensed electrician does prescribed electrical work. Isolate properly or do not go up the ladder.

What every home already owes

Class 1 and Class 2 dwellings — ordinary houses, townhouses, and the flats that share a residential building — must have one or more smoke alarms that comply with an approved standard. In practice that standard is AS 3786. The alarms must sit in locations that give occupants of bedrooms reasonable warning so they can get out. A single alarm over the kitchen is not a bedroom warning. A single alarm in a two-storey Burnside house, downstairs by the front door, is a hope. A long Norwood corridor with bedrooms off both sides is a different problem from a Salisbury open-plan box with one short hall. Fit them where sleeping people will actually hear them in time.

If the title transfers, South Australia gives the new owner six months to bring the alarms up to a higher power-source rule: mains-powered, or a ten-year-life battery that is non-replaceable, non-removable and permanently connected. That is the moment a lot of cheap nine-volt units quietly become illegal to rely on. If you bought before 1 February 1998 and have never sold, a replaceable-battery alarm can still be the letter of the older rule. It is also the unit that dies because someone took the battery for a bike light.

Dwellings built from 1 January 1995 sit under the Building Code requirement for 240-volt, mains-powered alarms. New dwellings, additions and extensions must interconnect, so that one alarm sounding sets the others off. Renovators in Goodwood keep missing that when they add a rear pavilion and leave the old hallway unit as a lonely chirp. Hard-wired alarms are electrical work. If you are unsure what is in the void, stop and hire a licensed electrician. Do not work live.

Photoelectric, ionisation, and the thing the fire service actually wants

Ionisation alarms are quicker on fast flaming fires — a waste-paper basket going up. Photoelectric alarms are better on the slow, smouldering furniture fire that fills a hallway with smoke before it makes a dramatic flame. Most people who die in house fires die in smoke, at night, in a bedroom off a hall.

The South Australian Metropolitan Fire Service has been blunt: photoelectric, interconnected, and more of them than the legal minimum if you can stand it. That is a recommendation with a uniform behind it. The law talks about an approved standard and locations that give reasonable warning. It does not, in the documents we are prepared to paraphrase, make every existing ionisation disc an immediate offence. Replacing one is the moment to stop buying the old type. If the unit still says “ionisation” and the date is a previous decade, treat replacement as overdue. Do not put a photoelectric alarm directly over the toaster and then declare smoke alarms impossible. Move it toward the hallway.

Power: nine-volt theatre, ten-year lithium, and mains

The chirp at 2am is a design. Nine-volt batteries run down, get taken out, get forgotten. South Australia’s transfer rule and the Building Code’s mains rule are both attempts to get households off that ritual.

A ten-year sealed lithium alarm — non-replaceable, non-removable, permanently connected — is the unit the transfer rule points at when mains power is not already there. You fit it, you test it, you replace the whole thing at the end of its dated life. Mains-powered alarms with battery backup are the new-build default, and they need a Certificate of Compliance if the work is prescribed. Interconnection on new work is not a nicety. A fire in a Thebarton lean-to should wake the person in the front bedroom.

Hard-wiring is not a DIY evening. Ceiling spaces in Prospect cottages are a biography of previous owners. You do not go rummaging live. You do not twist a new alarm onto a lighting circuit because the fitting was nearby. That is how people leave a working-looking alarm on a circuit that dies with the light switch.

Rentals, landlords, and the inspection that actually looks up

Residential landlords have to provide working smoke alarms. Consumer and Business Services puts the duty on the owner: the right type, enough of them, working at the start of a tenancy, and checked at inspections. Tenants should report a chirp or a missing alarm in writing. They should not take the alarm down because it objects to dinner, and they should not be asked to fund a mains upgrade as if it were a scented candle.

A landlord who fitted one ionisation unit in 2004 and calls that “compliant forever” is arguing with the transfer rule, the Building Code if the place is post-1995, and the fire service. Glenelg and Henley Beach flats fail this in different aesthetics from Burnside bungalows. The duty is the same. Hard-wired interconnection after an extension is construction work, not a Bunnings run by the tenant.

Bedrooms, hallways, storeys

The legal phrase is reasonable warning for occupants of bedrooms. The practical layout, which tracks the National Construction Code for new dwellings and the fire service’s advice for everyone else, looks like this:

An alarm in the hallway that serves the bedrooms, close enough that smoke from a living room fire hits it before the hall is a chimney.
An alarm on every storey, including a storey that is only a rumpus or a landing.
Alarms in bedrooms if you want the house to match how people actually die, which is behind a closed door.
Interconnection on new dwellings, additions and extensions, so the pavilion and the old hall agree.

Closed bedroom doors are the Adelaide summer habit that makes hallway-only coverage thinner than it looks. A child in a Prospect front room with the door shut for the air-conditioner is not in the same acoustic space as the hallway unit. Put a photoelectric alarm in the room. Interconnect it if you are already doing electrical work.

Do not treat a smoke alarm as a substitute for the rest of home electrical safety. A cooking smell that is actually a warm powerpoint is a different essay: warning signs of an electrical fault. A family house with shuttered powerpoints and no working alarm has solved the wrong half of the night. Child-safe circuits is the neighbouring piece. The rules hub is where licensing and Certificates of Compliance live if your “smoke alarm job” became a lighting circuit.

A smoke alarm is not a negotiation with the toaster. It is a small machine with one job, and the law already told you where that job is.

What to do on Tuesday

Test the button. If nothing happens, replace the unit or call someone who can. A disc older than ten years is a candidate. Prefer photoelectric, sealed lithium or mains with backup, and more than the minimum in a two-storey house. If you own a rental, look up during inspections.

Hard-wired work is a licensed electrician. If you have just bought, the six-month clock is not a rumour. A chirp is not “settling into the new weather”. SA Power Networks will not come for a hallway alarm. The Metropolitan Fire Service will come for a fire. The practical requirement is a working alarm, of a type the standard recognises, where sleeping people can hear it, powered in the way your building’s age and sale history demand, interconnected when the work is new. Everything else is taste, and taste is how houses fill with smoke while the only alarm sits above the grill.