Explaining in detail the smoke alarm locations’ requirements according to the most recent international and California residential building codes and NFPA 72 in new and existing residential properties.
Smoke detectors locations code requirements
Smoke detectors shall be installed according to section (R 314.3), in the following locations,
- In each bedroom.
- Outside bedrooms, ”hallway leads to a bedroom”. If the house has to separate hallways leads to separate bedrooms groups, two separate smoke alarms shall be placed in each hallway.
- On each level of the house, including basements and habitable attics and not including crawl spaces and uninhabitable attics.
When Smoke alarms required to be battery operated vs hard wired?
Smoke alarms permitted to be battery operated only if the following conditions occur section (R 314.6),
- No construction, just updating the smoke alarm throughout the house.
- Interior remodeling of the house without removing drywall, unless there is an access to the attic, crawl space or basement which could provide access for the house wiring without removing drywall.
- Where construction are limited to the exterior of the residential property, such as the reroofing or replacing siding, or the addition or replacement of windows or doors.
- Construction is limited to the installation, alteration or repairs of plumbing or mechanical systems or the installation, alteration or repair of electrical systems without removing drywall.
If any other type of constructions were not previously listed above, Smoke alarms shall be hard wired and equipped with a battery backup.
Un-permitted smoke detectors locations
Smoke alarms shall not be installed in the following locations according to residential code section (R314.3.3),
- It shall not be installed within 3 ft. from the door or opening of a bathroom that contains a bathtub or shower.
- It shall be installed a minimum of 20 ft. distance from a cooking appliance. which the main reason for smoke alarm goes off randomly.
- It shall not be installed within (3 ft.) horizon from the supply air registers of a forced air heating cooling system (HVAC).
- It shall not be installed within (3 ft.) from the tip of the blade of a ceiling-suspended ceiling fan.
Where should smoke alarms be placed in house?
| Locations | Smoke detectors requirements |
| Bedroom | Required-Every bedroom |
| Bathroom | Not Required- 3ft away from bathroom door |
| Living room | Required if it leads to a bedroom- No Hall way |
| Kitchen | Not Required- 20 ft. away from cooking appliance |
| Hallway | Required- leads to bedrooms |
| 1st, 2nd, 3rd story | Required-Every Level |
| Laundry room | Not Required |
| Basement | Required |
| Attic | Not Required |
| Habitable attic | Required |
| Crawl Space | Not Required |
| Garage | Not Required |
| AC Register | 3 feet away |
| Ceiling fan | 3 feet away tip of the blade |
Related: Where to install a carbon monoxide detector.
Smoke alarms Interconnection
Smoke detectors shall be interconnected when its required to be hard wired according to the residential codes as I mentioned above, which means when one smoke alarm goes off the rest of the smoke alarms within the same house shall go off as well.(R314.4).
Reference Codes – International Building Code – California Residential Code
This is some really good information about smoke detectors. Lately, I have been considering getting more of them in my smoke detector. I liked that you pointed out that you don’t need to put one in a laundry room. However, it might be a nice precaution because a fire could start there.