Opinion: Smoke Alarm Location

Interesting scenario today: Two co-workers hired me together to inspect two identical floor-plan homes that are almost next door to one another. The homes are both new construction, same builder/same super, finished at the same time. There were a number of differences in how some things were executed between the two homes. It’s interesting to see how much drift there is from house to house

One of the differences involved the required smoke alarm outside the master bedroom. In the attached image the open arched doorway leads to a small alcove with a return air chase and thermostat and the doorway to the master bedroom. House #2 (not the one in the photo) had the smoke alarm that is required to be outside of the sleeping area located inside the alcove approximately at the point of the lower arrow (this location I know is OK); House #1 had the same smoke alarm located as you see in the photo at the top of the arrow (on the upper level ceiling).

I’m curious as to whether you believe this location to be correct/acceptable or improper and why in either case.

I am leaning toward improper because I’m thinking that placing outside the open passageway constitutes it not being “in the immediate vicinity” for the sleeping room, even though the location is technically on the first floor.

Please give me your thoughts. I’ll hold out on finalizing the report comment until I’ve heard some opinions.


I would defiantly recommend them right in the bedrooms as the CPSC recommends in a case like this.
You want them 6 inches from the wall ceiling intersection and not near vents or dead air space.

That smoke alarm is not anywhere near the bedroom door. If it’s required to be out side the bedroom I’d write it up as being wrong.

Agree. No need to over-analyze it. It’s wrong, so report it as such.

I should have elaborated: There are smoke alarms inside of each sleeping room. The alarm in question is the one that is required to be located outside of each separate sleeping area.

Edit: Just found the location requirement in NFPA 72 “Outside of each separate dwelling unit sleeping area within 6.4M (21 feet) of any door to a sleeping room, the distance measured along a path of travel.”

Another pertinent section: "Where dwelling units include great rooms or vaulted/cathedral ceilings extending over multiple floors, smoke alarms that are located on the upper floor that are intended to protect the aforementioned area shall be permitted to be considered as part of the lower floor(s) protection scheme to meet the requirements of
Based on this, it appears that the location on the upper ceiling is OK**

BTW: smoke alarms should be located so that the closest edge is not less than 4 inches from the wall ceiling juncture, wall mounted units should have the top edge also not more than 12 inches below the wall ceiling juncture.

Your smoke is fine. It satisfies being within 21 ft of the door and it looks to be within 36 inches of the peak but not closer than 4.


Nevermind…I waited too long to type. You edited in the correcxt info.


Some code depends on location.
In Illinois it is with in 15 feet of bedrooms for both smoke and carbon monoxide detectors since Jan 1st of 2006.

That is if living space is considered in danger of Co2.

Central Boilers do not count in multi units.

So, it’s OK. But I would not want to rely on that smoke detector to wake me up in the middle of the night!

Are the smoke detectors in that house interconnected, so if one alarm sounds they all activate? This would be OK because of the alarm in each bedroom.

Yes all alarms are interconnected for smoke and CO alerts. It would be quite a challenge for a hearing person to sleep through these.