Seattle, WA Fire Regulations: Smoke Detectors (2026)
Key Facts
- Smoke detector placement
- 4-12 inches from ceiling, in/near sleeping rooms
- CO alarm placement
- every level & outside each sleeping room
- Testing trigger
- each time a unit becomes vacant
- Tenant record
- signed statement of understanding required
- Enforcing agency
- Seattle Dept. of Construction and Inspections
Summary
Seattle's housing code makes landlords install smoke detectors within 4 to 12 inches of the ceiling inside and outside every sleeping room, plus carbon monoxide alarms on every level, and test both devices whenever a housing unit becomes vacant between tenants.
4.Install smoke detectors on the ceiling or on the wall not less than 4 inches nor more than 12 inches from the ceiling at a point or points centrally located in a corridor, inside each sleeping room, and immediately outside each sleeping room, and test smoke detectors when each housing unit becomes vacant;5.Install carbon monoxide alarms outside each sleeping room and on each level of the dwelling unit, and inside any sleeping room that contains a fuel-burning appliance or fireplace, and test carbon monoxide alarms when each housing unit becomes vacant;6.Make all needed repairs or replace smoke detectors and carbon monoxide alarms with operating devices before a unit is reoccupied; and7.Instruct tenants as to the purpose, operation, and maintenance of the detectors and alarms and have the tenant sign a statement of understanding.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Municipal Code: Supplement 44 Update 1).
Full Breakdown
B sits in the "Duties of Owners" subchapter of the Housing and Building Maintenance Code and applies to every building containing rented housing units, regardless of what a lease says about shifting responsibility to a manager or tenant. 4 requires the owner to install a smoke detector on the ceiling, or on a wall between 4 and 12 inches down from the ceiling, at a point centrally located in each corridor, inside every sleeping room, and immediately outside every sleeping room. 5 adds a matching carbon monoxide alarm requirement: outside each sleeping room, on every level of the dwelling unit, and inside any sleeping room that itself contains a fuel-burning appliance or fireplace.
Both devices must be tested by the owner "when each housing unit becomes vacant", meaning between every tenancy, not on some fixed calendar schedule. 6 backs that up with a repair duty: the owner must make all needed repairs or replace non-functioning smoke detectors and CO alarms with operating devices before the unit is reoccupied. 7 requires the owner to instruct the incoming tenant on the purpose, operation, and maintenance of the detectors and alarms and to have that tenant sign a statement of understanding, creating a paper record that the devices were working and explained at move-in.
5 directly into the Rental Registration and Inspection Ordinance (RRIO) checklist that a qualified inspector uses to pass or fail a unit for its certificate of compliance.
Violations & Fines
A unit that fails to meet the detector and alarm placement or testing duties can be cited by the Seattle Department of Construction and Inspections under Chapter 22.206 with a notice of violation and compliance deadline, and separately fails the RRIO checklist items tied to 22.206.160.B.4 and .5, blocking the property's certificate of compliance under SMC 22.214.050 until the owner installs, repairs, or documents working devices and the signed tenant statement of understanding.
Frequently Asked Questions
Does Seattle require smoke detectors to be hardwired?
How often must a landlord test the alarms?
What happens if a unit fails an RRIO inspection over detectors?
Sources & Official References
Other rules in Seattle
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Smoke Detectors in Nearby Cities
How other cities in King County handle smoke detectors.