Smoke Alarm Count and Placement (IRC R314)

One in each sleeping room, one OUTSIDE each separate sleeping area, and one on each additional story including basements and habitable attics -- three bedrooms, one sleeping area, one extra story is five, minimum. The CLEARANCE depends entirely on the SENSING TYPE, and the spread is better than three to one: 20 ft horizontally from a permanently installed cooking appliance for ionization, 10 ft for ionization with a silencing switch, and 6 ft for photoelectric or an alarm marked to reduce cooking nuisance alarms. So an alarm 8 ft from the range fails as ionization and passes as photoelectric -- in an open plan, changing the type is usually the only way a required location works, and far cheaper than moving it. Also the 3 ft separation from a tub/shower bathroom door.

minimum alarms = sleeping rooms + separate sleeping areas + additional stories; required cooking clearance = 20 ft (ionization), 10 ft (ionization with a silencing switch), or 6 ft (photoelectric, or marked to reduce cooking nuisance alarms); bathroom separation = 3 ft horizontally from the door or opening of a bathroom with a tub or shower.

IRC R314.3 Location and R314.3.1 Installation near cooking appliances.

Both provisions are short prescriptive sentences reproduced in state adoptions and building-department bulletins. No table is reproduced.

Estimate. AHJ and licensed professional govern.

Field names used by the API: sleeping_rooms, sleeping_areas, additional_stories, alarm_type, distance_to_cooking_ft, distance_to_bath_door_ft, required_alarms, required_cooking_ft, cooking_deficit_ft, bath_deficit_ft

• Count each sleeping room + outside each separate sleeping area + each additional storyIRC R314.3
• Story exclusions crawl spaces and uninhabitable attics do not countIRC R314.3
• Cooking clearance 20 ft ionization, 10 ft ionization with silencing, 6 ft photoelectric or nuisance-listedIRC R314.3.1
• Bathroom 3 ft horizontally from the door or opening of a bathroom with a tub or showerIRC R314.3
• Exception separations yield where they would prevent a required location - a documented last resortIRC R314.3 / R314.3.1
• Not checked CO alarms, interconnection, power and battery backup, mounting geometry, existing-dwelling triggersstated scope limit