Oso, WA

Unincorporated Snohomish County does not have a stand-alone short-term rental permit ordinance, so operators are governed primarily by Washington's statewide framework in RCW 64.37 (enacted 2019). Operators must hold a state business license, carry $1 million in liability insurance (or use a platform that does) under RCW 64.37.050, post safety information and CO/smoke alarm compliance under RCW 64.37.030 and RCW 19.27.530, and remit state and local lodging and sales taxes under RCW 82.08. Incorporated cities (Snohomish, Edmonds, Everett, Lynnwood, Marysville) layer their own STR permits on top.

Snohomish County's Title 30 (Unified Development Code) does not set a numeric guests-per-bedroom cap for short-term rentals in unincorporated areas. Maximum occupancy defaults to the Washington State Building Code (RCW 19.27 / WAC 51-51), which adopts the IRC requirement of at least 70 sq ft for the first sleeping occupant and 50 sq ft per additional occupant. Bed and breakfast inns and guesthouses regulated under SCC 30.28.020 require a certificate of occupancy with annual inspection.

Snohomish County does not publish a separate STR-specific parking standard in Title 30 SCC. Off-street parking for an STR in an unincorporated single-family or duplex dwelling defaults to the residential minimums in the SCC parking chapter (generally two stalls per single-family home plus one per ADU). Bed and breakfast inns and guesthouses under SCC 30.28.020 add guest-room parking. On-street parking on county roads follows SCC Title 13 and the rules of the road in RCW 46.61.

Short-term rental operators in unincorporated Snohomish County must register statewide with the Washington Department of Revenue under RCW 64.37, collect Washington state retail sales tax, county/state lodging taxes under RCW 67.28, and remit them through the DOR combined excise tax return. The county does not levy a separate STR-specific permit fee; building, septic, and zoning fees follow the underlying use under SCC Title 30.

Fireworks in unincorporated Snohomish County are governed by the State Fireworks Law (Chapter 70.77 RCW) plus county discharge restrictions enforced by the Snohomish County Sheriff's Office. In legal areas of unincorporated Snohomish County, consumer fireworks may be discharged only on July 4 from 9:00 a.m. to 11:59 p.m. - all other dates and times of year are prohibited. Fireworks discharge has been banned year-round in the unincorporated Southwest Urban Growth Area since 2020-2021, and a 2024 county ordinance extends a sales ban to that area effective summer 2025. Most incorporated cities (Everett, Lynnwood, Edmonds, Marysville, Mill Creek, Mountlake Terrace, Mukilteo, Bothell, Brier, Arlington, Gold Bar, Index, Woodway) ban fireworks year-round.

Snohomish County Code Chapter 10.01 (Noise Control) regulates noise in unincorporated areas, with sound-level standards adopted from WAC 173-60. SCC 10.01.020 defines nighttime as 10:00 p.m. to 7:00 a.m. weekdays and 10:00 p.m. to 9:00 a.m. weekends. SCC 10.01.040 prohibits public disturbance noise originating from any property. Receiving residential property limits drop by 10 dB(A) at night - typically 50 dB(A) night versus 60 dB(A) day. Cities like Everett, Lynnwood, Marysville, and Edmonds enforce their own municipal noise codes within city limits.

Snohomish County Code 30.28.040 allows fences and freestanding walls up to 6 feet in height in any required front, side, or rear yard without a setback (unless a landscaped area is required). Building permits are not required for fences 6 feet or less; fences over 7 feet require a building permit per the Washington State Building Code. Up to three strands of barbed wire are allowed atop fences 6 feet or less. Where a fence sits on a retaining wall, height is measured from the uphill side. Cities within Snohomish County (Everett, Lynnwood, Edmonds, Marysville) have separate fence rules.

Snohomish County Code Chapter 9.14 (Dog Leash Law) requires any dog off its owner's property to be under the control of a responsible person. SCC 9.14.030 defines 'under control' as restrained by a secure leash or other restraint not more than 8 feet in length and held by a person capable of physically restricting the animal. Livestock running at large is prohibited. Dangerous and potentially dangerous dogs are regulated under SCC Chapter 9.20 and RCW 16.08. Animal Services: 425.388.3440 (3000 Rockefeller Ave, Everett). Cities like Everett, Lynnwood, Marysville, and Edmonds have their own leash codes.

Snohomish County regulates development in special flood hazard areas (SFHAs) under Snohomish County Code Chapter 30.65, which incorporates the National Flood Insurance Program (NFIP) minimum standards adopted on March 15, 1984. The chapter applies to FEMA-mapped 1%-annual-chance floodplains shown on the FIS and FIRMs dated June 19, 2020, including the Stillaguamish River (mouth to RM 11.1), Snohomish River, and Puget Sound shorelines. The Washington Shoreline Management Act (RCW 90.58) and the county's Shoreline Master Program impose additional setbacks within 200 feet of shorelines of statewide significance.