What Washington Requires for CO Detectors: Placement and Duties

Last verified: February 17, 2026

Washington carbon monoxide detector laws are anchored in RCW 19.27.530 and supporting code provisions such as WAC 51-51-0315. The statewide framework applies across covered homes, rentals, and many lodging-related residential occupancies, with trigger conditions tied to fuel-burning sources, fireplaces, attached garages, and code-governed occupancy pathways. Washington code text also addresses placement by sleeping-area proximity and story-level coverage in covered dwellings.

The statute includes role allocation language, including owner installation obligations and tenant maintenance responsibility in rental contexts identified by the law. Statewide enforcement is primarily carried out by counties and cities under local code administration authority.

Washington operators should preserve section-level citations, installation records, and maintenance history in each property file. Recording local code-administration contacts and inspection timelines for each jurisdiction further supports compliance readiness.

In 60 Seconds

CO detector requirements for Washington
Applies to homes?	Yes
Applies to rentals?	Yes
Applies to hotels/STRs?	Yes

When Are CO Alarms Required?

Buildings with fuel-burning appliances
Buildings with attached garages
New construction
Residential occupancy classifications in adopted code determine whether lodging-type properties fall under covered Group R pathways.
RCW 19.27.530 includes statutory exceptions where no listed carbon monoxide source condition exists.

Where to Install CO Alarms

Outside each separate sleeping area in the immediate vicinity of bedrooms under WAC 51-51-0315.
On each additional story of covered dwellings including basements and excluding uninhabitable attic or crawl-space contexts under WAC 51-51-0315.

For detailed placement guidance beyond legal requirements, see where to place carbon monoxide detectors.

Device Requirements

Install alarms in accordance with manufacturer instructions as required by WAC 51-51-0315.
Additional listing and technical details follow adopted Washington code pathways for the applicable occupancy.

Landlord and Tenant Responsibilities

Landlord: Property owners must install required alarms in covered dwellings and rental contexts under RCW 19.27.530.

Tenant: Tenant maintenance and replacement responsibilities are assigned by RCW 19.27.530 in covered rental-unit contexts.

Washington enforcement and implementation details can vary by local jurisdiction and code-administration practice.

Enforcement

Enforced by: Counties and cities enforcing state building code locally under RCW 19.27.060 and related administration pathways.

Enforcement typically occurs:

During permit and inspection workflow for covered construction and occupancy scenarios.
During local complaint or compliance review when required alarms are missing disabled or non-operational.

Penalties for Non-Compliance

RCW 19.27.530 does not provide one statewide stand-alone fine table for carbon monoxide alarm noncompliance in the cited section text.

RCW 19.27.530 with local enforcement administration under RCW 19.27.060.

Additional Notes

Washington compliance files should keep RCW and WAC citations together with occupancy classification records.
Local jurisdictions may have process differences for inspection scheduling and correction notices.

Official Sources & References

Revised Code of Washington section 19.27.530 — 19.27.530 (state code, accessed 2026-02-17)
Primary statewide statutory source for requirements, exceptions, and rental responsibility language.
Washington Administrative Code section 51-51-0315 — R315.2 and R315.3 pathways (building code, accessed 2026-02-17)
Placement and installation framework for residential carbon monoxide alarms.
Washington Administrative Code chapter 51-54A — Group R occupancy classifications including R-1 and R-2 contexts (fire code, accessed 2026-02-17)
Occupancy classification source for lodging and residential code applicability analysis.
Washington State Building Code Council carbon monoxide fact sheet — Public guidance summary (agency guidance, accessed 2026-02-17)
Supplemental agency guidance aligned to RCW and WAC references.

Disclaimer: This information is provided for general guidance and is not legal advice. Requirements may vary by city, county, and building type. Always verify current rules with local authorities and official sources.

Frequently Asked Questions

For Washington audits, which RCW-WAC citation is the primary legal anchor?

RCW 19.27.530 is the main statewide legal anchor, supported by placement language in WAC 51-51-0315. This combination sets the requirement framework for covered homes, rentals, and certain lodging-related occupancies. Owners should not rely on one summary sentence because exceptions and role allocation details are section-specific. Washington property files should keep RCW and WAC citations in the same packet so installation and maintenance decisions remain traceable during inspections. Include local enforcement contact details in that packet.

Under RCW and WAC, what Washington placement checks matter most?

WAC 51-51-0315 places alarms outside sleeping areas in immediate bedroom vicinity and on each additional story in covered dwellings, including basement levels in the listed scenarios. Placement should be documented room by room and matched to the locally enforced code edition. Teams should keep as-built location records and device details for each unit. Washington compliance outcomes are stronger when placement evidence and section citations are preserved together for audit and enforcement review.

How are landlord and tenant responsibilities split in Washington?

RCW 19.27.530 assigns owner installation duties in covered contexts and includes tenant maintenance and replacement responsibilities in rental scenarios identified by the statute. This means compliance workflows should include both owner and occupant action steps, not only installation checklists. Lease packets should identify reporting channels for non-operational devices and timelines for correction. Washington operators should keep notices and repairs in a dated log tied to the governing section. This log should include completion date and verifier.

What penalty table does Washington list for noncompliance?

The cited RCW 19.27.530 section does not present one stand-alone statewide fine table specific to carbon monoxide alarm violations. Even without a dedicated fine schedule in that section, local enforcement and liability exposure can still be significant when required alarms are missing or disabled. Teams should prioritize prompt correction and preserve proof of remediation. Washington compliance notices should cite RCW 19.27.530 and local enforcement instructions. Keep each notice linked to the property compliance timeline.

In Washington, which RCW-WAC triggers can still apply to all-electric units?

Not automatically. Washington scope depends on statutory exceptions, occupancy classification, and local interpretation of risk conditions in the adopted code framework. Owners should avoid broad assumptions and verify exemption logic with the local authority having jurisdiction before finalizing status. Written exemption records are important for turnover, insurance, and incident review. Washington files should store the exact section language used to justify each exemption. Include the approving authority and decision date.

For Pacific portfolios, what Washington compliance step differs most from Oregon?

Washington in this dataset relies on RCW and WAC integration with local code administration, while Oregon combines ORS remedy language, OAR rules, and ORSC pathways. Regional teams should keep separate Pacific Northwest matrices instead of one shared policy baseline. For side-by-side process work, review Oregon CO detector laws and compare trigger timing, remedies, and documentation expectations. Washington teams should separate RCW records from Oregon ORS and OAR references. Keep local agency contacts in both state files before launching regional updates.

Practical CO Detector Guides

Beyond legal requirements, these guides help you choose, install, and maintain CO alarms:

Where to place carbon monoxide detectors — room-by-room placement recommendations
CO detector beeping patterns — what different alarms mean
What to do if your detector goes off — emergency response checklist
CO resources and links — official agencies and safety information