One of the most common mistakes homeowners make when fitting out their home with smoke alarms is treating every room the same. The reality is that different spaces present very different fire and false-alarm risks, and the right alarm for a bedroom is not the right alarm for a kitchen.
Getting this wrong does not just mean wasted money. Installing a smoke alarm in a kitchen leads to constant false triggers from cooking, which typically results in the alarm being disabled. Installing a heat alarm in a bedroom, on the other hand, may not detect a smouldering fire until it has already spread significantly.
This guide breaks down exactly which alarm type suits each room in your home, and why.
The Two Main Alarm Types
Photoelectric smoke alarms
Photoelectric smoke alarms detect visible smoke particles using a light-scatter detection chamber. They are the standard requirement for NZ homes and are particularly effective at detecting slow, smouldering fires, which are the most common residential fire type. They are sensitive to airborne particles, which makes them unsuitable for rooms where steam, grease, or cooking fumes are present.
Heat alarms
Heat alarms do not detect smoke. They respond to either a rapid rise in room temperature or a fixed temperature threshold being reached. Because they are immune to airborne particles, they produce no false alarms from cooking or steam. They are slower to activate than smoke alarms in a smouldering fire scenario, which is why they are not recommended as the primary alarm type in living and sleeping areas.
Room-by-Room Guide
Bedrooms
Alarm type: Photoelectric smoke alarm
Bedrooms are the highest-priority location for smoke alarm protection. A fire that starts while you are asleep gives you the least time to respond, and a smoke alarm in or near each bedroom is your first line of defence.
Under NZS 4514:2021, a smoke alarm is required within 3 metres of each bedroom door, measured along the ceiling. Installing one inside each bedroom as well is strongly recommended, particularly in larger homes or where bedroom doors are kept closed at night.
Living Rooms and Lounges
Alarm type: Photoelectric smoke alarm
Living areas are frequently occupied spaces with a range of potential ignition sources, including electrical equipment, candles, fireplaces, and soft furnishings. A smoke alarm on the ceiling of each living area, positioned centrally and away from air vents, provides early detection.
In open-plan layouts where the living area flows into a kitchen, position the smoke alarm toward the living end of the space, as far from the cooking zone as practical.
Hallways and Landings
Alarm type: Photoelectric smoke alarm
Hallways and landings are critical detection points because they connect sleeping areas to the rest of the home. Smoke travelling through a hallway will reach a centrally placed alarm quickly, giving occupants early warning before fire reaches bedroom areas.
At minimum, one smoke alarm is required in each hallway on each level of the home. For longer hallways (over 12 metres), consider two alarms positioned along the length.
Kitchen
Alarm type: Heat alarm
The kitchen is the most common source of false alarms in any home. Steam from boiling water, smoke from high-heat frying, and airborne grease particles will all trigger a photoelectric smoke alarm. Installing a smoke alarm in the kitchen typically leads to it being disabled within weeks. A wireless heat alarm is the correct choice here. It will not trigger from normal cooking activity but will activate when temperatures reach dangerous levels and alert the entire interconnected system.
Under NZS 4514:2021, a heat alarm is specifically recommended for kitchens and sculleries separated from living areas by a door.
Garage
Alarm type: Heat alarm
Garages present a unique challenge. Vehicle exhaust, fuel vapours, and dust from tools and equipment make smoke alarm installation impractical. A heat alarm provides reliable fire detection without nuisance triggers from day-to-day garage activity.
Because garages are often physically separated from the main living areas, it is particularly important that the garage heat alarm is interconnected with the rest of the home’s alarm system, so occupants inside the house are alerted immediately.
Laundry
Alarm type: Heat alarm
Steam from washing machines and dryers, combined with lint and airborne particles, makes laundries a poor environment for smoke alarms. A heat alarm is the appropriate choice and will activate reliably if a dryer fire occurs, which is one of the more common household appliance fires in New Zealand.
Bathroom
Alarm type: Not required, but position nearby hallway alarm carefully
Bathrooms themselves do not require a smoke alarm, but the hallway outside a bathroom should be positioned so the alarm is not directly in the path of steam from a shower or bath. Keep the hallway alarm at least 1.5 metres from the bathroom doorway where possible.
The Importance of Interconnection
Regardless of alarm type, all alarms in your home should be interconnected. When your kitchen heat alarm triggers, every smoke alarm in your bedrooms and hallways should sound at the same time. This is how you ensure that a fire starting in one part of the home alerts everyone everywhere.
Quick Reference Summary
- Bedroom: Photoelectric smoke alarm
- Lounge / living area: Photoelectric smoke alarm
- Hallway / landing: Photoelectric smoke alarm
- Kitchen: Heat alarm
- Garage: Heat alarm
- Laundry: Heat alarm
- Bathroom: No alarm required (manage nearby hallway placement)
Key Takeaways
Choosing the right alarm for each room is not complicated once you understand the fundamental difference between smoke and heat detection. Match the alarm type to the environment it will operate in, interconnect everything, and you have a system that is both reliable and free of nuisance triggers.On Point Distribution supplies the full CAVIUS range of photoelectric smoke alarms and heat alarms for every room in your home. View our full fire safety product range or visit our FAQ for further guidance on alarm selection and placement.