Beyond the Minimum
Garages, Sheds and Where the EV Charges
Everything above is about the alarms the regulations require, and those live in the hallways and sleeping areas. A garage is a different problem, and it is not covered by doing the legal minimum well.
Garages defeat ordinary smoke alarms. They run hot in a Perth summer, they fill with exhaust and fumes every time a car starts, and they collect dust off the floor. Put a standard photoelectric alarm in one and it will either nuisance-trip until somebody takes the battery out, or get mounted somewhere it will never see anything. That is why detection in a garage is usually a heat question rather than a smoke question, sometimes with carbon monoxide alongside it where a combustion vehicle lives in the same space.
The reason it comes up now is what is parked in there. An electric vehicle charging overnight in an attached garage is worth more than the contents of most houses, and it sits against a shared wall while everyone is asleep. Detection in that space is a reasonable thing to want, separate from anything the Building Regulations ask of you. What fire authorities recommend for EV garages →
Ajax FireProtect 2: heat, smoke and CO versions, in black or white.
It does not have to begin as a whole security system. Ajax FireProtect 2 detectors work on their own without a hub. They sound their own siren, and where more than one is fitted they trigger each other, so an alarm in the garage wakes the house. What they cannot do without a hub is reach your phone. Add a hub later and the same detectors start reporting to the Ajax app, with nothing already installed needing to be replaced. If a charger install is happening anyway, that is the visit where adding detection in the same space costs least.