Interactive toolkit
Three tools that turn the guidance on this site into an answer for your own building. All of them run in your browser — nothing is sent anywhere, and nothing is stored.
1 · How many alarms does your home need?
Enter the size and shape of the dwelling and the calculator returns a device count, a per-storey figure and the spacing rules it applied. It uses the travel-distance and spacing logic of the British and American domestic codes as a sanity check on ordinary residential rooms — treat the result as a starting point for a proper design, not as a substitute for one.
Coverage calculator
Roughly 70 m² of flat ceiling per smoke alarm, with circulation and sleeping-space rules applied on top.
2 · Is that mounting position any good?
Click any of the numbered positions on the floor plan to see the verdict and the reasoning. The rooms and the positions are typical of a two-storey family home, which is where most placement mistakes happen.
Placement checker
Eight candidate positions, from the textbook-correct to the ones that cause nuisance alarms.
Click any numbered marker. The verdict explains what the fire code expects at that point and what the air around it is doing.
3 · Which device suits this room?
Describe the building, the power available and the room, and the selector returns a device class with the reasoning and the certification regime that applies. It suggests a type of device, not a brand — the point is to help you write or check a specification.
Product selector
Five questions. The result is a specification class, not a sales recommendation.